Simple Machines

What is a Simple Machine?
Simple Machines are basic mechanical devices for applying a force and doing work. More complex machines are made up of a bunch of simple machines. Everyday you use machines without even thinking about it. A machine is anything that helps make work easier. Basic tools like staplers, screwdrivers and scissors are simple machines. These machines are all based on simple inventions like levers, planes, pulleys or wheels.

Fast Facts!

  1. Simple machines were first discovered and described by Greek philosopher Archimedes.
  2. The Egyptians likely used the inclined plane to help build the pyramids. Using ramps would have made getting the large stones to the top much easier.
  3. Galileo was the first to work out a working mathematical theory on how simple machines worked.
  4. Your bicycle makes use of nearly every kind of simple machine in order to make a more complex machine.
  5. The wheel and axle was an important invention in the history of mankind. It was first used around 5,000 years ago by the Sumerians.​
How did the Egyptians build the Great Pyramids thousands of years ago (~2,500 BCE)? Could you build a pyramid using 9,000-kilogram (~10-ton or 20,000-lb) blocks of stone with your bare hands? That's like trying to move a large elephant with your bare hands! How many people might it take to move a block that big? It would still be a challenge to build a pyramid today even with modern tools, such as jackhammers, cranes, trucks and bulldozers. But without these modern tools, how did Egyptian workers cut, shape, transport and place enormous stones? Well, one key to accomplishing this amazing and difficult task was the use of simple machines.

Simple machines are devices with no, or very few, moving parts that make work easier. Many of today's complex tools are really just more complicated forms of the six simple machines. By using simple machines, ordinary people can split huge rocks, hoist large stones, and move blocks over great distances.
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However, it took more than just simple machines to build the pyramids. It also took tremendous planning and a great design. Planning, designing, working as a team and using tools to create something, or to get a job done, is what engineering is all about. Engineers use their knowledge, creativity and problem-solving skills to accomplish some amazing feats to solve real-world challenges. People call on engineers to use their understanding of how things work to do seemingly impossible jobs and make everyday activities easier. It is surprising how many times engineers turn to simple machines to solve these problems.
How do Simple Machines help us?
Illustrate the power of simple machines by asking students to do a task without using a simple machine, and then with one. For example, create a lever demonstration by hammering a nail into a piece of wood. Have students try to pull the nail out, first using only their hands and then introduce a hammer. Furthermore, Think of how much work it would be to pick up a car to take it to the mechanic if we had to do all the work ourselves. Luckily we have a machine called a tow truck that makes it easier.  What are other types of machines we use?

Machines make our work easier.

Bring in a variety of everyday examples of simple machines. Hand out one out to each student and have them think about what type of simple machine it is. Next, have students place the items into categories by simple machines and explain why they chose to place their item there. Ask students what life would be like without this item. Emphasize that simple machines make our life easier.
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One of the first things you want your students to know about any topic is why it is important. If you are teaching your students about simple machines, they need to understand how important simple machines are to our lives. They need to know, how do simple machines help us?

Simple machines are one of the most important inventions in human history. On the surface, simple machines are used to help reduce effort and energy through a mechanical advantage. They help enhance a person’s ability to tackle specific tasks that would otherwise be difficult with our bare hands. Simple machines help us do work more easily. They don't change the total amount of work needed to move something, but they make it easier by reducing the force required. 

Work is a combination of force and distance. So, when we increase the distance an object moves, the force needed decreases.

Simple machines work in a single motion, and if we combine several of them, we get a compound machine that can do more complex tasks. Scientists enjoy creating these compound machines, often called Rube Goldberg Machines. A Rube Goldberg machine is a device that performs a set of interconnected steps to complete a simple task. A ball might run down a ramp, trigger a sequence of dominoes, which then trigger another action, and so on. The sequence continues until the final task is completed. 

We use simple machines because they make work easier. Work, scientifically defined, is the force applied to an object multiplied by the distance it moves. Each task requires a specific amount of work, and that doesn't change. So, the force multiplied by the distance always equals the same amount of work.

The trade-off between force and distance, known as mechanical advantage, is present in all simple machines. With mechanical advantage, the longer it takes to do a job, the less force you need to use throughout the job. Usually, tasks feel difficult because they demand a lot of force. Therefore, by using the trade-off between distance and force, we can make our tasks much easier.
Simple Machines vs. Compound Machines
Simple machines can be combined to create compound machines. Compound machines can be as small as a mechanical watch or as large as a construction crane. Some, such as a car, contain thousands of parts.

In a compound machine, forces and motion are transferred from one part to another. One way this is done is with gears. A gear is typically a circular piece of metal with teeth, or ridges, along its outer edge. The teeth of one gear fit into those of another. When one gear turns, it also turns the other gear. Another way of transferring forces and motion is with a type of pulley that uses a chain or a band of flexible material called a belt.

A bicycle is an example of a compound machine that uses a chain to transfer force. The chain runs around two separate toothed wheels, which act as pulleys. One is attached to the axle of the rear wheel. The other is attached to the pedals through an axle. The pedals work like the crank of a wheel-and-axle machine. The force used to turn the pedals becomes a stronger turning force on the axle and its toothed wheel. The chain transfers the force to the rear wheel and makes it turn. In some bicycles the chain can be shifted between toothed wheels of different sizes. This changes the amount of force the rider needs to turn the rear wheel.​

Another example of a compound machine is a wheelbarrow. In a wheelbarrow, the functionality of a wheel and axle combines with a lever. Numerous compound machines can be created through the use of six basic simple machines. Some additional examples of compound machines are a can opener, shovel, and a jack.
Force 
Force is a simple PUSH or PULL. A PUSH moves an object away. A PULL brings it closer.
Lets understand with some examples of force ( i.e. push or pull).

When you throw a ball, it means you are applying force to push it away from you. Or, when you are opening the drawer, it means you are applying force to pull it towards you. Suppose you are asked to move a table. In how many ways can you move it?

When you push the table, it moves or when you pull the table it still moves. It means force can make a static object move. Static object is an object that can’t move. 


Force can be as small as a nudge or as big as a shove. There are many forces around us every day. Such as riding your bike, kicking a ball, flying a kite, riding your skateboard, etc.
What effect do Forces have on Objects? 
Force can..
  • make something move
  • speed up
  • slow down
  • stopping object 
  • change direction
  • or even change shapes 
Force + Force Reduction
Force, the essence of a push or pull on an object, manifests in various forms like friction, gravitational, electric, buoyant, spring, tensional, magnetic, and applied. Engaging a force to move an object across a distance signifies the accomplishment of work. Whether it's pushing a box or pulling open a door, our daily activities involve exerting forces. Even when leveraging machines for increased force, known as mechanical advantage, we enhance our capabilities.

Yet, force isn't solely about movement; it extends to situations like a game of tug-o-war. Pulling on a rope may not constitute work if nothing moves, but if the opposing team succumbs, work is unequivocally done. In the realm of basic mechanical devices, the likes of levers and inclined planes strategically apply 'force reduction.' These devices, exemplified by a seesaw or a ramp, optimize our efficiency by minimizing the force required for tasks.

Consider the lever, where adjusting the distance between the force and fulcrum eases lifting heavy objects with minimal exertion. Inclined planes, another simple machine, facilitate the upward movement of bulky items, demanding less force than direct lifting. From the seesaw's pivotal point to ramps aiding in loading boxes onto trucks, these examples underscore how simple machines ingeniously incorporate force reduction, streamlining our daily endeavors.
Different Types of Forces + Examples 
Force can be classified into two broad categories

Contact forces: These are those types of forces when two objects interact with each other; they have a physical contact with each other. Types of contact forces are: Frictional force; Tension force; Normal Force; Air Resistance Force, Applied Force, Spring Force.

Frictional force
As an object moves across a surface it causes friction. Friction force can be sliding or static. Friction depends upon the nature of the two interacting surfaces. Example: A book sliding on the table, a ball rolling on the floor.

Tension force
A force that is transmitted through a string, rope, cable or wire when it is pulled tightly by the object on the opposite end is a tension force. This force flows across the length of the wire or rope. Example- A cable car or climbing a mountain using a rope.

Normal force
This is the force exerted upon an object that is in contact with another stable object. Usually a normal force is applied horizontally between two objects in contact. Example-A book resting on a table or a person leaning on the wall.

Air Resistance force
This a frictional force applied on objects when they are in air. Often the Air Resistance force opposes the movement of the object. It is noticeable for objects that travel at high speed up in the air. Example- An airplane or a parachute.

Applied force
A force with which an object has been pushed or pulled. Here a force is applied to an object by a person or any other object. Example- A person pushing a chair to the other side of the room

Spring force
It is the force which results when a spring is stretched or compressed. A spring is a metal elastic device that returns to its original form when pulled or pressed. If the spring is stretched, spring force is attractive. If it is compressed, spring force is repulsive. Example- Trampoline, diving board etc.

Action at a distance forces: These types of forces happen when two interactive objects are not in physical contact with each other; yet they are able to push or pull. Types of Action at a distance forces are: Gravitational force, Electrical force and Magnetic forces.

Gravitational force
This is the force by which the Earth or moon or other massively huge objects attract another object towards them. All objects on the Earth experience the gravitational force, which is directed downwards towards the center of the earth. The force of gravity is always equal to the weight of the object.

Electrical force
It is one of the fundamental forces of the Universe. It is a force that exists between all charged particles. It is all around us. It is responsible for making our hair stand on a cold day. When the hair on the head stands and refuses to be brushed, that is static energy. It is this force which allows you to see when you turn on the lamp in a dark room.

Magnetic force
This is a push or pull exerted by a magnet. The force of attraction between an object and a magnet is called magnetism. All magnets have north and south poles. This force is the attraction or repulsion that arises between electrically charged particles due to their motion. Example- Iron nails when placed near a magnet.
Mass + Force
Lets understand with an example. Your friend gives you three covered boxes to push.

You pushed all three boxes. Which box were you able to push easily and which box did you find hard to push?

Your answer is Box C. Well-done! You are right.

Do you know ? Why did you find it difficult to push box C? Because box C is filled with rocks that are heavier than paper and cotton ball filled boxes A and B respectively.

Have you ever wondered why rocks are heavier than cotton balls and paper? That’s because rocks have more MASS than cotton balls and paper. Objects that are heavy or have more mass need more force to move it. That’s why you found it difficult to push box C.

What is Mass?
Mass is the amount of matter (i.e., electrons, protons and neutrons) in an object.
Mass is usually measured in kilograms which is abbreviated as kg.

If two objects are the same mass, and different forces are applied to them. The object that receives the greater force will move faster, and the object that receives the lesser force will not move as fast.

Question for kids – What would it take to slow down or stop a heavier object?

Answer is, to slow down or stop a heavier object, the force must be greater than what it would to slow down a smaller object
Push or Pull
  1. Open the drawer to get a pencil, what are you doing? (Push/Pull)
  2. Rolling a ball (Push/Pull)
  3. Press on the wall (Push/Pull)
  4. Drawing a bucket of water from well (Push/Pull)
  5. When you High Five with your friend (Push/Pull)
  6. When you are raising the bottom of the book in the air, what are you doing? (Push/Pull)
  7. If you raise your cute teddy bear by its ear, what are you doing? (Push/Pull)
Playground Physics 
Take it outside to introduce young children to physics concepts! Here are some ideas for exploring those topics on a preschool playground:

Pendulums:
Hang a swing and let the children observe how it swings back and forth. Discuss the concept of a pendulum and how gravity is causing the swing to move. Have the children experiment with pushing the swing gently and then with more force to observe the changes in its motion.

Gravity:
Use the opportunity of the swing to talk about gravity. Explain that gravity pulls objects towards the Earth and that's why the swing comes back down after being pushed.

Force and Motion:
Allow children to experiment with pushing and pulling objects on the playground. Discuss how a push or a pull can make an object move.
Create a simple ramp with a board or slide and let children roll balls down it. Discuss how the force of pushing the ball makes it move.

Inertia:
Use a roundabout (merry-go-round) on the playground to demonstrate inertia. Start it spinning and then stop it suddenly, discussing how objects want to keep moving in the same direction.

Push and Pull:
Set up a small wagon or cart and let the children take turns pushing and pulling it. Discuss the difference between a push and a pull and how they affect the motion of the wagon.

Simple Machines:
Point out simple machines on the playground, like slides, swings, and see-saws. Discuss how these machines make it easier for us to do work (move or lift things).

Newton's Law:
Simplify Newton's laws by introducing the idea that objects like the swing or a ball want to stay still unless a force (push or pull) acts on them. Use simple examples to illustrate each law.
Remember to keep it fun and interactive, allowing the children to explore and discover these concepts through hands-on play. Encourage questions and observations to promote a deeper understanding of basic physics principles.
Mechanical Advantage
The term mechanical advantage is used to describe the number of times a simple machine multiplies the effort force applied. The mechanical advantage is the ratio of the load force to the effort force, or, MA= F load ¸ F effort. This ratio gives an idea of the effectiveness of a simple machine in reducing work.
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​Mechanical Advantage, a captivating concept intricately linked to the realm of simple machines, is certain to grab the attention of young minds. This notion serves as a measure of the extent to which force amplification occurs when employing tools, mechanical devices, or machine systems. Delving into the example of a seesaw, a fundamental machine operating on the lever principle, offers us a clearer understanding of this intriguing concept.

Consider the seesaw: the farther the distance from the fulcrum, the less effort is required to elevate the person on the opposite end, all thanks to the Mechanical Advantage facilitated by the lever! This fundamental principle extends its influence to an array of other simple machines, including pulleys, inclined planes, wheels, axles, screws, and wedges. Each of these leverages Mechanical Advantage to streamline and enhance the efficiency of challenging tasks, demonstrating the fascinating interplay of physics and engineering in the world of simple machines. Engaging with these concepts not only provides valuable insights but also sparks curiosity about the mechanics that surround us in everyday life.

Work
Work is defined as an amount of force (or effort) to move an object a distance. Simple machines make work easier by multiplying, reducing, or changing the direction of a force.
The equation is simple: W = FxD
Simple machines cannot change the amount of work done, but they can reduce the effort force that is required to do the work!
As you can see by this formula, if the effort force is reduced, distance is increased.

Understanding work in physics means grasping the connection between force and energy. By helping students comprehend this concept, we provide them with a broader view of the world and insight into how simple machines assist us. Simple machines, such as a wheelbarrow, make us more efficient by allowing us to apply force over greater distances, optimizing our muscle power.

There are six basic types of simple machines: lever, wheel and axle, pulley, inclined plane, wedge, and screw. Each of these alters either the direction or magnitude of a force, enhancing our capacity to do work. This means we can achieve the same amount of work with less energy or take on a heavier workload without increasing our effort.

To understand work, students should know that it involves force and distance. For older students, trigonometry may be necessary to calculate work when force isn't parallel to the motion. However, younger students can start by grasping the basic concept, setting them up for success later.

Additionally, students should recognize that work represents a change in energy, requiring an understanding of kinetic and potential energy to comprehend how simple machines aid us.

Examples are crucial in teaching work. Students should witness instances where work is done and cases where it's not, despite the application of force or distance. Keep in mind that force is the product of mass and acceleration, so an object moving at a constant velocity without friction experiences no force, and therefore, no work is done on it.
Consider This:
Ask the class what work they would like to do when they grow up. What does it mean to work? Before we learn about simple machines, we need to learn some science (specifically physics) words. Let’s start with work.

​Put a box of books that is too heavy for the children to lift off the floor. Ask the child to lift the box on the table. Once they get past the “I can’t do it” part, have them problem solve how they can accomplish their work.  They can take the books out/move the box/put the books back in or have a friend help them. No matter how they accomplish it, how long it takes, or who helps it is still the same amount of work.
  • As they try ask, "Are you doing any work? No!
  • Why not? You haven’t moved the box of books.
  • Are you using energy to try to lift that box? Yes!
  • According to scientists, work is defined as moving a mass over a distance. How do they define work?
  • Okay, now what can they do to actually do the work? How can they lift this box of books onto the table?
    • The child could take one book out of the box at a time until the child can lift the box by themselves and then put all the books back in the box.
    • A few people could help the child
    • The child could build a contraption to lift it up there.
  • Have the child get the box of books on the table either way. Regardless of which way we solve the problem, would the amount of work done the same? Yes. Regardless of how we did it, we lifted the heavy box with its contents to the table.
  • Did the box weigh the same when two, three or four people lifted it? Yes, it weighed the same, but the people shared the work.
  • When you were lifting the box to the table what force were you working against? Gravity.
  • When we do work we use energy. What do you think energy is? Scientists define energy as the ability to cause change; can change the speed, direction, shape, or temperature of an object.
  • Who used energy in doing the work of lifting the box? Everyone who helped had to use energy to get the work done.
  • Who remembers the definition of work? (Moving a mass over a distance) What work was done here? This box, this mass, we raised (moved) it how many inches?
  • When you were moving the box the force of gravity was working against you; making it heavy to lift.
  • You used energy to lift the box.
  • When you worked together you each had to use less power to accomplish the same work.
Force + Work
Physicists came up with the law of machines, which states that little effort applied over a long distance can lift a great weight over a short distance. 

What do you think force means? We mentioned that gravity is a force. A force is a push or a pull. What is force?

Newton’s First Law of Motion says that objects at rest will remain at rest unless acted upon by an unbalanced force. Objects in motion will remain in motion at the same speed and direction unless acted upon by an unbalanced force.

Have one child lightly push another child. Have a third child push a fourth child harder. You are all demonstrating force. Physicists, who are scientists who study how things move, measure force in Newtons or pounds. Which child exerted more Newtons or pounds?

All simple machines transfer force. Some change the direction of force, some change the strength of the force, and some change both the direction and the strength. Most simple machines make work easier by allowing you to use less force over a greater distance to move an object. Some machines make work easier by allowing you to move things farther and/or faster. In these machines, a larger force is required, but over a shorter distance.
Power
​Power is the rate of work or the ability to do work or get things done. Once students understand work, power should be easier to understand. Simple machines make work easier by increasing distance and decreasing force. That is the key point in learning how do simple machines help us.
​In the context of simple machines, power is related to how quickly or easily a task can be accomplished. Imagine you have a friend named Mr. Push who helps you move things around. Now, Mr. Push has different amounts of power depending on how he uses it.

Lever: 
Mr. Push has a seesaw (lever) to lift a heavy object. If he pushes closer to the heavy object, it's easier for him to lift it because he uses less power. But if he pushes farther away, it's harder for him, and he needs more power.
Lesson: The position where Mr. Push applies his power on the lever affects how easy or difficult it is for him to lift things.


Wheel and Axle:
Now, Mr. Push has a big wheel (like a doorknob) that he turns to open a door (wheel and axle).
If the wheel is large, he can turn it with less effort, making it easier for him to open the door.
Lesson: The size of the wheel and axle can affect how much power is needed to do a task.

Pulley:
Imagine Mr. Push using a pulley to lift a heavy bucket.
If he uses more pulleys, it becomes easier for him to lift the bucket because the load is shared among multiple ropes.
Lesson: More pulleys can make a task easier by spreading the load.

Inclined Plane:
Mr. Push has a ramp (inclined plane) to move a heavy box.
It's easier for him to push the box up the ramp than lifting it straight up.
Lesson: Using an inclined plane can make it easier to move things vertically.

Screw:
Now, Mr. Push has a screw to attach two things together.
If the screw has more threads, it's easier for him to twist and join the things together.
Lesson: The design of the screw can affect how easy it is to twist and fasten things.
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So, power in simple machines is all about finding ways to make tasks easier by using different tools and techniques. Kids can think of it like figuring out the best way for Mr. Push to get his work done without using too much effort!
We will learn about the different simple machines, which are; Incline Plane, Lever, Wedge, Screw, Wheel and Axle, and the Pulley. ​
Six Different Simple Machines
  1. ​Inclined Plane: is a slanting surface connecting a lower level to a higher level.
  2. Lever: is a stiff bar that rests on a support called a fulcrum which lifts or moves loads.
  3. Wedge: is an object with at least one  slanting side ending in a sharp edge, which cuts material apart.
  4. Screw: is an inclined plane wrapped around a pole which holds things together or lifts materials.
  5. Wheel and Axle: a wheel with a rod, called an axle, through its center lifts or moves loads.
  6. Pulley: is a simple machine that uses grooved wheels and a rope to raise, lower or move a load.​
Inclined Planes
​Inclined planes, which constitute one of the six types of simple machines, consist of flat surfaces sloping or tilting from one end to another. These planes facilitate tasks by providing a surface where one end is higher than the other.

This design enables the movement of heavy objects to higher points through sliding rather than lifting, as it is generally more manageable to slide an object than to lift it. Recognizable to children as ramps, slides, or hills, these machines possess a distinctive ability to facilitate the upward movement of heavy objects with reduced force.
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For example, the task of lifting a substantial box and placing it directly into a truck can be quite demanding. However, utilizing an inclined plane, such as a ramp, to slide the same box significantly alleviates the effort involved. This efficiency arises from the fact that inclined planes reduce the force required to elevate heavy items by extending the distance over which the force is applied.
How do Inclined Planes help us?
An inclined plane helps make lifting things easier by making the object travel a longer distance. Instead of lifting something straight up, like a wheelbarrow, you can push it up a slanted surface (inclined plane). This way, you end up in the same spot, but it feels easier because you cover more distance and use less force. Simple machines like inclined planes make lifting heavy stuff easier for us. That's how they help us.
Examples of Inclined Planes
1. Slides: the inclined surface helps one slide down easily.
2. Ramps: they assist in moving heavy objects up or down.
3. Wheelchair ramps: they make it easier for wheelchairs to access higher or lower levels.
4. Roads or hills: their sloped surfaces aid vehicles in moving up or down.
5. Ski slopes:  they allow skiers to slide down a slope.
6. Escalators:  they transport people between different levels.
7. Ladders: they create an inclined path for climbing up or down.
Try This!
  • Experiment: "Rolling Down the Ramp"

Materials:
A sturdy board or plank (ramp)
Small toy cars or balls
Building blocks or books to elevate one end of the ramp
Optional: Tape, markers, or craft materials for decorating the ramp

Procedure:
Introduction (5 minutes):
Start by introducing the concept of inclined planes to preschoolers. Explain that inclined planes are surfaces that are slanted, making it easier to move objects up or down.

Setup (5 minutes):
Place the ramp on a flat surface and elevate one end using building blocks or books.
Ensure that the ramp is secure and won't slip.

Experiment (15 minutes):
Allow the children to place small toy cars or balls at the top of the ramp and observe how they roll down.
Discuss the concept of the inclined plane and how it helps the objects move.
Encourage them to try different angles of inclination and observe how it affects the speed of the objects rolling down.
Physics in the Classroom
Children learn some basics of physics when playing in the block center with ramps. During play with these objects, children make observations and comparisons with the speed or direction of the toys. Encourage vocabulary such as:
slope
fast
slow
up
down
higher
lower
push
pull​
Questions/Discussion
  • What happens when you place a toy car at the top of the ramp?
  • How does the inclined plane make it easier for the toy car to move?
  • Can you make the car go faster by changing the angle of the ramp?
  • Why do you think inclined planes are useful?
  • What might happen if we used a different object?
  • Which object will roll down faster, the marble, or the can of soup?
  • What happens if...you make the ramp higher or lower?
  • What happens if...you try and push the object up the ramp?
  • How might we...get the items to roll into each other?
  • How might we...make the ramp more stable?
Family Connection
  • Suggest families explore inclined planes in their home, such as stairs or ramps for bikes and skateboards.
  • Encourage parents to help their children create their own ramps using household items like cardboard, books, or wooden planks.
  • Ask the children to experiment with different materials on their homemade ramps, such as rolling different toys or objects.
  • Prompt families to find examples of inclined planes in their community, such as wheelchair ramps or driveways.
  • Practice identifying ramps you see on walks, drives, or looking at pictures.
  • Consider a family engineering challenge. Can you make a pillow slide the entire length of the kitchen? What about making a ball roll over obstacles in the backyard? Can we make a ramp as tall as you are?

Dive Deeper
  • Extension Activity: "Friction Fun on the Ramp"

Materials:
Ramp (from the previous experiment)
Small toy cars or balls
Various materials to create friction (e.g., carpet, sandpaper, fabric, plastic wrap)
Optional: Tape, markers, or craft materials for decorating the ramp
Procedure:

Introduction (5 minutes):
Briefly revisit the concept of inclined planes and discuss how inclined planes are used to make objects move. Introduce the concept of friction and explain that it's a force that can slow down or stop moving objects.

Setup (5 minutes):
Place the ramp on a flat surface and elevate one end using building blocks or books.
Attach different materials to the surface of the ramp to create friction. For example, secure carpet, sandpaper, fabric, and plastic wrap on different sections of the ramp.

Experiment (15 minutes):
Allow children to place small toy cars or balls at the top of the ramp and observe how they roll down on the different surfaces with varying levels of friction.
Discuss how the materials added to the ramp create friction and affect the movement of the objects.
Encourage them to compare how the cars or balls roll on surfaces with high friction (e.g., carpet) versus low friction (e.g., plastic wrap).

Discussion Questions:
  • What happens when you roll a toy car down the ramp with carpet? How about with plastic wrap?
  • Which surface creates more friction, and which one allows the car to go faster?
  • How does friction affect the movement of the toy car?
  • Why might friction be important in certain situations?

Extension Activities for Home:
  • Suggest families explore friction at home by trying different surfaces (e.g., tabletops, floors) and observing how toys or objects move.
  • Encourage parents to help their children create additional ramps with various friction-inducing materials found at home.
  • Ask preschoolers to experiment with everyday objects (e.g., different types of shoes) on surfaces with varying levels of friction.
  • Prompt families to find examples of friction in their community, such as car tires on different road surfaces.
This extension activity adds an additional layer to the inclined plane experiment by introducing the concept of friction. It encourages young learners to observe and understand how different materials on the ramp can influence the movement of objects, promoting a deeper exploration of basic physics principles.
Lever 
A lever, a fundamental component among the six simple machines, consists of a straight rigid object like a board or bar pivoting on a fulcrum. Levers harness the concept of leverage, amplifying force to make work more manageable. When utilizing a lever, a smaller force is applied over a longer distance to lift a load a shorter distance.

In our daily lives, levers play a crucial role, aiding in the movement or lifting of heavy objects with minimal effort. These versatile machines are integrated into various items we regularly encounter, such as seesaws, scissors, and tweezers, all operating based on the same core principle.

This principle involves three key elements: the effort (force applied to the lever), the fulcrum (pivot point), and the load (the object to be moved). What sets levers apart is their adaptability—by adjusting the fulcrum's position, it becomes possible to shift or lift larger objects with reduced exertion, showcasing the remarkable capabilities of levers.

Examples of levers include seesaws, pliers, crowbars, and tweezers, all demonstrating the simple yet effective machine's ability to multiply force.
How do Levers help us?
A lever is like a simple tool that helps you move things. It has a long bar and a point in the middle where it can turn. This turning point is called the fulcrum. You push down on one side of the bar, and it makes something on the other side move.

A lever has three main parts: where you push (effort), the thing you want to move (load), and the point in the middle (fulcrum). Levers can be different types based on where these parts are.
  1. First class levers: The fulcrum is in the middle, between where you push and what you want to move. Like a seesaw.
  2. Second class levers: The thing you want to move is in the middle, between where you push and the fulcrum. Like a wheelbarrow, where the wheel is the fulcrum.

Levers make it easier to move stuff around!
Try This!
  • Experiment: "Balancing Act with Levers"
Materials:
A ruler or a sturdy wooden plank
Small objects (such as building blocks, toy cars, or small toys)
A fulcrum (a small object like a wooden block or a small plastic container)
Optional: A small container or cup

Procedure:
Introduction (5 minutes): 
Start by discussing the concept of levers in simple terms with the preschoolers. Explain that levers are tools that help lift or move things. Use everyday examples like seesaws or a crowbar to illustrate the concept.

Setup (5 minutes):
Place the ruler or plank on the fulcrum (the small object) to create a simple lever.
Demonstrate how the lever works by placing a small object on one side of the ruler.
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Experiment (10 minutes):
Encourage the children to explore and experiment with the lever by placing different objects on each side.
Discuss how the lever moves and what happens when different objects are placed on either side. Ask questions like, "What happens when you put a heavy object on one side and a light object on the other?" 
​Let them try to balance the lever by adjusting the position of the objects.
Questions/Discussion
  • When have you had to move something heavy from down low to high up?
  • How can you making lifting something heavy easier?
  • What did you observe when you placed different objects on the lever?
  • How did the lever move when you added a heavy object?
  • Can you make the lever balance by adjusting the position of the objects?
  • Why do you think the lever moves?
Family Connection
  • Encourage families to find and explore other examples of levers in their home, such as using a seesaw at the park or playing with a crowbar.
  • Create a lever at home using a ruler and a household object as a fulcrum, experimenting with different objects to discover how weight affects balance.
  • Have the children draw pictures or take photos of levers they find or create at home and share their findings with the family.
Examples of Levers
1. Seesaw: this playground staple is a classic example of a lever.
2. Door handle: pushing or pulling a door operates as a lever.
3. Scissors: the two blades work as levers when cutting.
4. Crowbar: it helps lift or move heavy objects.
5. Wheelbarrow:  it uses a lever to lift and carry loads.
6. Nutcracker: it works as a lever to crack open nuts.
7. Tongs: they use a lever to grip and hold objects.
   Fun Fact: Though the definitions for types of catapults vary, each share one goal: to hurl an object through the air. The word "catapult" comes from the Latin word catapulta and the Greek word katapaltēs, meaning "to hurl."
Dive Deeper with Levers by building a Catapult
  • Experiment: "Catapult Creations"

What is a Catapult? 
A catapult is a simple machine that uses a lever and tension to launch or throw objects over a distance. It typically consists of a lever arm, like a long stick, and a launching platform, such as a spoon or cup, to hold the object being thrown. By applying force to the lever arm, often through the use of tension created by rubber bands or other elastic materials, the catapult propels the object into the air. Catapults have been historically used for various purposes, including in warfare and as a tool for exploration.

Materials:
Craft sticks (about 10 per child)
Rubber bands
Plastic spoon (one per child)
Small pom-poms or soft balls
Small plastic container or cup
Optional: Markers, stickers, or decorative materials for decorating the catapult

Procedure:
Introduction (5 minutes):
Begin by introducing the concept of levers and catapults to the class. Explain that levers are simple machines that can be used to lift or launch objects. Briefly mention how catapults are a type of lever used for launching things.

Setup (5 minutes):
Give each child craft sticks and rubber bands.
Instruct them to create a base by stacking the craft sticks and securing them with rubber bands. This will serve as the lever arm.
Attach the plastic spoon to one end of the craft stick stack, creating a launching platform.

Experiment (15 minutes):
Demonstrate how to use the catapult by placing a small pom-pom or soft ball in the spoon and pressing down on the other end of the craft stick.
Allow preschoolers to experiment with their catapults, adjusting the angle of the spoon and the force applied to launch the objects.
Encourage them to launch the pom-poms into a small plastic container or cup.

***Optional Extensions:
Allow students to make various versions of the catapult. Students can then test the best design by determining which catapult launches the object the furthest and the highest.
Students can experiment with the amount of effort, or force, used when pushing down on the end of the catapult. Students can observe the best amount of force to launch further or higher. 

Discussion Questions:
What type of simple machine is this? How do you know?
How does this simple machine perform work? How does it make work easier?
What are the different parts of this lever?
How did you make the pom-pom go far with the catapult?
What happens when you change the angle of the spoon or adjust the craft sticks?
How does the catapult use a lever to launch the pom-pom?
Why do you think catapults were used in the past?

Extension Activities for Home:
Suggest families explore other examples of levers at home, such as using a seesaw or a door as a lever.
Encourage parents to help their children create different types of catapults using household materials like spoons, rubber bands, and craft sticks.
Ask families to experiment with launching lightweight objects of different sizes and shapes using their homemade catapults.
Prompt the children to draw pictures or take photos of their catapults and share their creations with their family.

This experiment engages preschoolers in a hands-on exploration of levers through the creation of a simple catapult. The extension activities encourage families to continue the learning experience at home and explore other examples of levers in their environment.
The Mechanics of a Catapult
A typical catapult consists of several key components, each contributing to its functionality:
  • Catapult arm: The catapult arm is the long wooden beam or lever that holds the projectile. It is the part that moves when the catapult is fired.
  • Tension: Tension, often created by twisted rope or other means, stores the energy required to launch the projectile.
  • Sudden release: When the tension is suddenly released, it transfers the stored energy to the catapult arm, causing it to swing rapidly and launch the projectile.
  • Counterweight (in some designs): Some catapults, like trebuchets, use a counterweight to generate force. The counterweight is raised and then dropped, creating the energy needed for the launch.
  • Wheels (in some designs): Some larger catapults are mounted on wheels to facilitate movement and positioning.
How do Catapults Work?
This is a great simple physics activity for kids of multiple ages. What is there to explore that has to do with physics? Let’s start with energy including elastic potential energy. You can also learn about projectile motion.

Newton’s 3 Laws of Motion state that an object at rest stays at rest until a force is applied, and an object stays in motion until something creates an imbalance. Every action causes a reaction.

When you pull down the lever arm all that potential energy gets stored up! Release it and that potential energy gradually changes over to kinetic energy. Gravity also does its part as it pulls the object back down to the ground.

To delve deeper into Newton’s Laws, check out the information here.

You can talk about stored energy or potential elastic energy as you pull back on the Popsicle stick, bending it. When you release the stick, all that potential energy is released into energy in motion producing the projectile motion.

A catapult is a simple machine that has been around for ages. Have your kids dig up a little history and research when the first catapults were invented and used! Hint; check out the 17th century!
Learn more...
Wheel + Axle
The wheel and axle, a fundamental simple machine, enhances our ability to move and lift objects effortlessly. This mechanism consists of a larger circular component, known as the wheel, and a smaller rod-like structure, the axle, centrally attached. As the wheel is set in motion, both components rotate together, demonstrating its functional synergy.

This ingenious invention finds application in various everyday items such as doorknobs, car wheels, and roller skates. Beyond reducing friction for easier object movement, the wheel and axle play a crucial role in transportation, addressing challenges that would otherwise be formidable.
How does a Wheel + Axel help us?
A wheel and axle is like a big wheel connected to a small rod called an axle. It's easier to turn the big wheel because it travels a longer distance compared to the axle.

Think of a screwdriver as an example. The handle of the screwdriver is bigger than the end, making it easier to turn. So, simple machines like wheel and axle help us do things more easily.
Friction + Gravitational Force
When we have to move a real heavy load, we have to use a great deal of force to push it because of friction and gravitational force. A wheel and axle fixes this problem in a jiffy. 

What is Friction?
Force resisting the motion of the object on the ground.

What is Gravitational force?
Force that pulls the object to the ground.

The “Wheel and axle” solves this problem! In this simple machine, a wheel is locked to a central axle and they rotate each other when a force is applied on either one of them.

When we place a heavy load on the axle and push it, the rolling of the wheels reduces the friction to a large extent. However, the frictional force does not depend on the surface area of the object. The friction depends on its mass and what material it is made of. When there is less friction, it takes less force to move something.
To learn more about Gravity + Friction visit the links below:
Examples of Wheels + Axles
1. Car: the wheel and axle work together to help the car move.
2. Bicycle: the wheels rotate around the axle when riding a bike.
3. Rollerblades/Skates: the wheels spin around the axles for movement.
4. Wagon or cart: the wheels turn around the axles to carry loads.
5. Doorknob: turning the knob rotates the spindle (axle) to open or close a door.
6. Toy cars or trucks: the wheels spin around the axles for movement.
7. Lawnmower: the wheels rotate around the axles to move the lawnmower forward or backward.
Try This!
  • Experiment: "Rolling Fun with Wheels and Axles"

Materials:
Cardboard tubes (from paper towels or wrapping paper)
Plastic bottle caps
Wooden dowels or sturdy straws
Craft materials (colored paper, markers, glue, tape)
Small objects (e.g., toy cars, small figurines)
Optional: Paints and brushes

Procedure:
Introduction (5 minutes):
Start by introducing the concept of wheels and axles to the the class. Explain that wheels and axles are simple machines that make it easier to move objects. Show examples like toy cars or wagons.

Setup (5 minutes):
Distribute cardboard tubes, plastic bottle caps, wooden dowels, and other craft materials.
Demonstrate how to create a simple wheel and axle by attaching a plastic bottle cap to each end of a wooden dowel using tape or glue.

Experiment (15 minutes):
Encourage the children to create their own "rolling objects" using the provided materials.
Let them experiment with different combinations of wheels and axles to create unique rolling toys.
Have them test their creations by rolling them on a smooth surface.
Questions/Discussion
  • Describe a time when you needed to push something heavy.
  • What kinds of things do you use that have wheels?
  • How did you make your rolling toy move?
  • What happens when you change the size of the wheels or the length of the axle?
  • Can you make your rolling toy go faster or slower?
  • Why do you think wheels and axles are useful for moving things?
Family Connection
  • Ask families to explore the concept of wheels and axles at home by identifying them in everyday objects like toy cars, strollers, or carts.
  • Encourage parents to help their children create more advanced rolling toys using recycled materials found at home.
  • Have the children measure the distance their rolling toys travel and compare the results.
  • Prompt families to go on a "wheel hunt" around the house or neighborhood and create a collage or drawing of the different wheels and axles they find.
Learn more...​
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Pulley
A pulley, a type of simple machine, employs a wheel with a groove and a rope. The rope is threaded through the groove, with one end looping around the load while the other end is pulled. This mechanism facilitates the movement of the load or redirection of force.

Various examples of pulleys abound, ranging from cranes and flag poles to window blinds. When multiple pulleys are utilized in tandem, it forms a block and tackle system. Another application involves flat wheels and belts, commonly found in cars. Pulleys, ubiquitous in a child's daily encounters, function to lift heavy objects with minimal effort by distributing the weight across a larger area, simplifying the lifting process.

Encountered in diverse settings like window blinds, flag poles, and playground equipment, pulleys are also integral components in more intricate machinery such as cranes and elevators designed for handling exceptionally heavy loads. As children grasp the mechanics of pulleys, they concurrently acquire insights into physics and engineering principles, recognizing how simple machines enhance the convenience of our everyday lives.
How does a Pulley help us?
​A pulley is like a wheel with a rope around it, and it helps make lifting things easier. It does this in two ways. First, it lets you pull down on the rope to lift something instead of pulling up. Second, if you add more wheels to the pulley, it makes the rope longer and reduces the force needed to lift things.

Using a pulley with one wheel changes the direction of the force, but it doesn't make it easier to lift. If you use a pulley with two wheels, it not only changes the direction but also makes it half as hard to lift things. So, if it took 500 units of force before, now it only takes 250 units. Adding more wheels makes it even easier to lift things. That's one way simple machines, like pulleys, help us.
Different Types of Pulleys
There are three types of pulleys, namely, fixed pulleys, movable pulleys, and compound pulleys.

Fixed pulleys are those pulleys that are attached to a single point. As the name suggests that this pulley is stationary and is fixed to support like wall or ceiling and the rope/chain passes through it. These are vital mechanical devices as they change the direction of the object, which is very helpful.

Movable pulleys are different types of pulleys as they move with the object and unlike the fixed pulley; they need little effort to lift the heavy objects. They multiply the effort made on them. The drawback of using these pulleys is that they do not change the direction of the object.

Compound pulleys are the combination of the fixed pulleys and movable pulleys. They have both the qualities of the fixed and movable pulley. They need little force to lift the heaviest objects and they can change the direction of the objects being lifted.
The Science behind a Pulley System
The science behind a pulley system lies in the principles of mechanics, particularly those related to forces and motion. By understanding these concepts, we can explore how pulleys work and the scientific principles that govern their operation.

Force and Motion: According to Newton’s laws of motion, when a force is applied to an object, it causes the object to experience acceleration or change in motion. In the case of a pulley system, the force is applied to lift or move an object.
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Mechanical Advantage: One of the key concepts in pulley systems is mechanical advantage, which refers to the ratio of the output force (effort) to the input force (load). Pulleys can increase mechanical advantage, allowing a smaller input force to exert a larger output force. This happens by distributing the load across multiple ropes or changing the direction of the force.

Tension and Load Distribution: When a force is applied to one end of a rope in a pulley system, it creates tension throughout the rope. This tension is transmitted to the load, allowing it to be lifted or moved. In a multiple-pulley system, the load is distributed among the different ropes and pulleys, reducing the amount of force needed to lift the load.

Conservation of Energy: Pulley systems also operate based on the principle of conservation of energy. Although they can provide mechanical advantages, they cannot create energy. The work done by the effort force is equal to the work done against the load force. In other words, the energy input equals the energy output, neglecting any losses due to friction or other factors.

Friction: While pulleys are designed to minimize friction, it is still a factor that affects their efficiency. Friction between the rope and the pulley wheels can reduce the effectiveness of the system and require additional force to overcome. Lubrication and proper maintenance can help minimize friction and optimize the performance of the pulley system.
Examples of Pulleys
1. Flagpole: a pulley system raises and lowers the flag.
2. Blind cords: pulling a cord operates a pulley to open or close blinds.
3. Well bucket: a pulley helps lift water from a well.
4. Elevator: elevators use pulleys to move up and down.
5. Zip line: a pulley system enables movement along the line.
6. Gardening hoist: a pulley lifts heavy pots or tools in the garden.
7. Exercise machines:  some gym equipment uses pulleys to adjust resistance.
Mechanical Advantage + Pulleys
Any machine’s purpose is to provide a better and increased output for a given input. The mechanical advantage is the term that defines the effectiveness of any machine. There are three types of mechanical advantages: Force, Distance, and Speed. Though the mechanical advantage of simple machines is a significant factor in measuring their performance, it can be used for highly complex machines also.

In the case of pulleys, to measure the performance of the pulleys force mechanical advantage is in use. It defines how effective the pulleys are. In theoretical terms, the mechanical advantage is the ratio of the force utilized to the force applied to the work.
Facts about Pulley
  1. Examples in our everyday world include blinds, garage doors, and even a flagpole.
  2. ​These simple machines have been around for thousands of years. The origin is not entirely known, but some historians believe that Mesopotamians used this simple machine to life water as long ago as 1500 BF.
  3. Archimedes was an ancient Greek scientist who invented the pulley and other simple machines such as the lever.
  4. ​The most significant advantage of a pulley system is that it can double the strength applied from the pulley to lift the weight.
  5. Other names for pulleys include a drum or a sheave.
Try This!
  • Experiment: "Up and Down with Pulleys"

Materials:
Thick string or yarn
Small plastic container or basket
Small toys or objects with varying weights
Hook or sturdy attachment point (e.g., a doorknob, tree branch, or curtain rod)
Optional: Colored markers, stickers, or decorative materials for decorating the container

Procedure:
Introduction (5 minutes):
Begin by introducing the concept of pulleys to the class. Explain that pulleys are simple machines that help lift or move objects. Use simple examples like raising a flag on a pulley system.

Setup (5 minutes):
Tie one end of the string to the handle of the plastic container or basket.
Thread the other end of the string over the hook or attachment point, creating a simple pulley system.

Experiment (15 minutes):
Demonstrate how the pulley works by placing a small toy or object in the container and pulling on the free end of the string to lift it.
Allow the children to take turns pulling on the string to raise and lower the container with different toys inside.
Encourage them to experiment with different weights and discuss how it feels to lift heavier or lighter objects.
Questions/Discussion
  • When have you had to move something heavy from down low to high up?
  • When have you had to pull something? What kinds of things are difficult to pull?
  • How does the pulley system help you lift the container?
  • What happens when you put a heavy toy inside? How about a light toy?
  • Can you make the container go up and down smoothly?
  • Why do you think pulleys are useful for lifting things?
Family Connection
  • Challenge families to find examples of pulleys in their home or community, such as window blinds, flagpoles, or well systems.
  • Invite parents to help the little learners to create a simple pulley system at home using materials like a clothesline and a small basket.
  • Ask families to explore different ways to make lifting objects easier at home, discussing the use of pulleys in everyday life.
  • Encourage children to draw pictures or take photos of their pulley systems and share them with their family.
Learn more...​
Wedge
A wedge is a simple machine used to push two objects apart. If you put two inclined planes back to back, you get a wedge. A wedge is a triangular shaped tool, a portable inclined plane, and one of the six simple machines. It can be used to separate two objects or portions of an object, lift up an object, or hold an object in place. 

Examples of the wedge include knives, chisels, and axes.

In their everyday lives, children frequently encounter wedges, a type of simple machine, often without even noticing. Characterized by two inclined planes arranged back to back, wedges are designed to alter the direction of force, facilitating the cutting or splitting of objects, or securing them in place.  This mechanism is utilized in commonplace items like knives, axes, doorstops, and even certain playground slides, making these items recognizable examples of wedges for kids. An intriguing aspect of wedges is their efficiency; the sharper a wedge is, the less force is required to perform its function, demonstrating its effectiveness as a simple machine.
How do Wedges help us?
A wedge is like a portable slanted tool. It can split things, such as when an ax splits a log. It can also stop things, like a doorstop, and lift things, like a plow lifting soil.

Similar to other simple machines, a wedge makes it easier to do work by making the force needed less and increasing the distance over which the work is done.

When using a wedge, like when splitting a log with an ax, you push down, but the sides of the log move outward. This makes it easier to push down on the wood than to pull it apart. So, in simple terms, wedges help us by making work easier and changing the direction of force.
​Wedge Vocab
  • Wedge: a simple machine used to separate or hold together materials
  • Separate: divide, tear, or move apart
  • Secure: hold in place; make stable
Facts about Wedges​
  1. A wedge is a simple machine.
  2. It’s a type of inclined plane.
  3. Used to split or cut objects.
  4. Converts force into a splitting action.
  5. Has a thin edge and a wide base.
  6. Increases force efficiency.
  7. Common in axes and knives.
  8. Reduces the effort needed for tasks.
  9. The oldest known wedge is from 8000 BC.
  10. Also used in doorstops and chisels.
Examples of Wedges
1. Knife: a knife uses a wedge to cut through objects.
2. Axe: an axe's wedge shape splits wood when chopping.
3. Doorstop: it holds a door open by using a wedge.
4. Chisel: it separates materials by applying pressure at its wedge-shaped tip.
5. Nail: a nail's pointed end works as a wedge when hammered into wood.
6. Zipper: a zipper's teeth function as wedges to fasten or unfasten.
7. Tacks: they secure things to a surface by piercing in with their wedge shape.
Try This!
  • Experiment: "Wedge Fun with Slicing Shapes"

Materials:
Playdough or modeling clay
Plastic knife or a butter knife (blunt and safe for children)
Various soft materials (e.g., fruits like bananas or soft vegetables)
Optional: Craft foam or cardboard, glue, and markers for creating wedge shapes

Procedure:
Introduction (5 minutes):
Begin by introducing the concept of wedges to preschoolers. Explain that wedges are simple machines with a pointed shape that can be used to split or separate things.

Setup (5 minutes):
Give each child a small amount of playdough or modeling clay.
Provide a plastic or butter knife for each child.

Experiment (15 minutes):
Instruct the children to use the plastic knife to cut or slice through the playdough.
Discuss how the knife has a wedge shape and how it helps in cutting or separating the playdough.
Encourage them to experiment with cutting different shapes and sizes using the wedge-shaped knife.​
Questions/Discussion
  • How does the wedge-shaped knife help you cut through the playdough?
  • Can you think of other objects or tools with wedge shapes?
  • What happens when you press the wedge harder or softer into the playdough?
  • Why do you think wedges are helpful in cutting or splitting things?​
Family Connection
  • Encourage families to explore wedges in the kitchen by involving preschoolers in cutting soft fruits or vegetables with a safe knife.
  • Have parents help their children create wedge shapes from craft foam or cardboard, decorating them with markers.
  • Ask families to find examples of wedges in their homes or community, such as doorstops, cutting tools, or even the tip of a pencil.
  • Prompt the children to explore how wedges are used in everyday life, such as cutting food, splitting objects, or holding doors open.​
Learn more...​
Screw
A screw is essentially a specialized form of an inclined plane, coiled around a central pole. This simple machine, often employed unconsciously in everyday activities, serves various functions, including lifting objects and fastening them together. Its distinct design enables bidirectional movement, depending on the turning direction.

Examples of screw simple machines are ubiquitous in daily life, ranging from swivel chairs and jar lids to common screws. Beyond their role in mundane items, screws play a vital part in tools like screwdrivers and drills, significantly enhancing efficiency and simplifying various tasks.

How do Screws help us?
A screw is like a twisted ramp around a stick. When you turn the screw, it can make things go up the twisted ramp. Screws are handy for holding things together.

Examples of screws are jar lids, bolts, drill bits, light bulbs, water faucets, and the ends of hoses.

Just like other simple tools, screws make it easier to do work by making us use less force. It's easier to push a screw into a wall than a nail because the edges of the screw move in a circle and cover a longer distance than a nail. This is one way simple tools make our work easier.

Screws are also useful because the twisted ramp edges keep the screw in place and help hold things together.
Examples of Screws
1. Screwdriver and screw:  turning the screwdriver drives the screw into or out of a surface.
2. Jar lids: twisting the lid on or off utilizes a screw-like mechanism.
3. Lightbulbs: twisting them into a socket works like a screw.
4. Clamps:  tightening or loosening a clamp involves a screw mechanism.
5. Corkscrew:  it uses a screw to insert into a cork for opening bottles.
6. Hooks and bolts: turning them involves a twisting motion like a screw.
7. Vise grips: turning the handle tightens or loosens the grip using a screw mechanism.
 Picture
Parts of a Screw
A screw is simply an inclined plane around a cylinder. To describe this better, you can view it as a cylinder with a head (solid top) at one end and a pointed tip (like a nail) at the other end. More importantly, it has ridges winding around it. The correct term for the ridges (or grooves) around the shaft or cylinder is the thread.

The distance between threads is the same for each screw but is different on other screws. The distance between threads is called a Pitch.
Nails vs. Screws
Using some scrap wood, experiment by using screw drivers to drive in screws of different types into the wood. 

Which takes more turns to screw it in?
Which screw do you think will hold better? Why?
Which screw has the most distance wrapped around it?
Which requires more work?

Then screw a screw through a two stacked up cardboard boxes. Then we put a nail through the plates. ASK the kids what they thought would hold better? They found that a screw held better.
Try This!
  • Experiment: "Twisting and Turning with Screws"

Materials:
Corks (one per child)
Small plastic or wooden beads
Small screw or wood screw
Screwdriver (appropriate for children's use)
Optional: Paper, markers, and stickers for decorating the corks

Procedure:
Introduction (5 minutes):
Start by introducing the concept of screws to the children. Explain that screws are simple machines that have spiral threads and are used for holding things together or lifting objects.

Setup (5 minutes):
Give each child a cork and a small plastic or wooden bead.
Show them the small screw and the screwdriver.

Experiment (15 minutes):
Demonstrate how to use the screwdriver to twist the screw into the cork, leaving enough space for the bead to be threaded onto the screw.
Instruct the children to use the screwdriver to twist the screw into the cork.
After screwing it in, show them how to thread the bead onto the screw.​
Questions/Discussion
  • How did the screw go into the cork?
  • What happens when you turn the screw with the screwdriver?
  • Why do you think the screw stays in the cork even after you stop turning it?
  • How is a screw different from other objects we've explored?
Family Connection
  • Encourage families to explore screws around the house, pointing out examples in furniture, appliances, or everyday objects. Remember lids are also a type of screw (milk cap, toothpaste lid, etc.). Notice how some lids stayed on better and were less likely to spill – the ones that were screwed on tightly.
  • Have parents help their children create a simple screw-based project, such as attaching small wooden pieces together using screws.
  • Prompt children to observe how screws are used at home and discuss their findings with their family.
  • Ask families to find examples of screws in the neighborhood or during outings, such as in construction sites or playground equipment.
Learn more...​
Physics + Engineering Basics
Simple machines, fundamental tools in physics, simplify our work by enabling us to exert less force over a larger distance, and their understanding can help kids grasp key science concepts. These include levers, pulleys, wedges, wheels and axles, inclined planes, and screws. Introducing engineering for kids with simple machines adds an exciting dimension to their learning experience, making it both educational and engaging.

Levers, similar to seesaws, aid in lifting heavy items with less effort by spreading the force over a longer distance. Pulleys, on the other hand, assist in heavy lifting by altering the force direction. Incorporating engineering concepts for kids, such as building their own miniature pulley systems, can make the learning process hands-on and interactive.

Wheels and axles help objects to glide smoothly across surfaces, thereby reducing friction. This can be demonstrated through practical activities, encouraging kids to design and build their own miniature vehicles incorporating wheels and axles, fostering creativity and problem-solving skills. Inclined planes, such as ramps, facilitate the upward movement of bulky objects with less effort, showcasing the practical applications of these simple machines.

Screws, essentially inclined planes wrapped around a rod, can either hold things together or lift objects. Engaging kids in constructing their own simple machines, like a screw-based device, enhances their understanding of how these tools function. By merging engineering for kids with the exploration of simple machines, educators can create a dynamic learning environment where theoretical concepts come to life through hands-on activities. These simple machines all operate based on basic physics principles, laying the foundation for a broader understanding of science and engineering for young learners.
Why do Engineers care about Simple Machines? 
​How do such devices help engineers improve society? Simple machines are important and common in our world today in the form of everyday devices (crowbars, wheelbarrows, highway ramps, etc.) that individuals, and especially engineers, use on a daily basis. The same physical principles and mechanical advantages of simple machines used by ancient engineers to build pyramids are employed by today's engineers to construct modern structures such as houses, bridges and skyscrapers. Simple machines give engineers added tools for solving everyday challenges.
Simple Machines Investigation Questions/Discussion
  • General Understanding:
​What is a simple machine?
Can you name some simple machines we use every day?
How do simple machines make our lives easier?
What are the six types of simple machines?
  • Lever:
What is a lever?
Can you think of examples of levers we use at home?
How does a seesaw work as a lever?
  • Pulley:
What is a pulley and how does it help us?
Can you find a pulley at home or in your neighborhood?
How do pulleys make lifting things easier?
  • Inclined Plane:
What is an inclined plane?
Can you find examples of inclined planes in our home or community?
How does an inclined plane make it easier to move things?
  • Wedge:
What is a wedge?
Can you find objects at home that have wedge shapes?
How do wedges help us in our daily lives?
  • Screw:
What is a screw?
Where can you find screws in your home?
How do screws help hold things together?
  • Wheel and Axle:
What is a wheel and axle?
Can you find examples of wheel and axle in your toys or household items?
How does a wheel and axle help things move?​

Engineers and Simple Machines:
What is an engineer, and what do they do?
Can you think of different types of engineers (e.g., mechanical engineer, civil engineer)?
How do engineers use simple machines in their work?

Real-world Applications:
Can you imagine situations where engineers use levers in construction or machinery?
How might a civil engineer use pulleys in building structures or bridges?
In what ways do engineers incorporate inclined planes in their designs?
What are the considerations an engineer must keep in mind when designing a new structure?
What are the considerations an engineer must keep in mind when choosing a site to build a new structure? ​

Problem Solving:
How do engineers use simple machines to solve problems?
Can you think of an example where a simple machine helps make a task easier or more efficient?
Why is it important for engineers to understand and use simple machines?
Family Connection
  • Simple Machines Scavenger Hunt: Encourage families to go on a scavenger hunt at home or in their neighborhood to find examples of simple machines. Take photos or draw pictures of the machines they discover. See how many you can find around your house! Use the attached Simple Machines Scavenger Hunt! Worksheet to conduct a fun scavenger hunt. Have the students find examples of all the simple machines used in the classroom and their homes.
  • Counting and Categorizing Simple Machines: Search for simple machines used in your daily life and categorize them to see which types of simple machines you use most often.
  • Show + Tell: Have the children bring  in everyday examples of simple machines from home and demonstrate how they work.
  • Everyday Engineering: Challenge families to create a simple machine at home using everyday materials. For example, they can build a lever using a ruler and a small object.
  • Explore the Kitchen: In the kitchen, identify simple machines such as wedges (knife), wheels and axles (rolling pin), and screws (can opener). Discuss how these machines make cooking and meal preparation easier.
  • DIY Projects: Encourage families to engage in simple DIY projects that involve using basic tools and simple machines. For example, creating a ramp for toy cars or a pulley system for lifting small objects.
  • Outdoor Exploration: Explore simple machines in outdoor settings, such as finding examples of wheels and axles in bikes or pulleys in playground equipment. Discuss how these machines contribute to outdoor activities.
  • Meet an Engineer: Arrange a virtual or in-person meeting with an engineer (if possible) to discuss their work. Ask them how they use simple machines in their projects and daily tasks.
  • Engineering Challenges: Create engineering challenges at home where families can work together to solve problems using simple machines. For example, building a structure with blocks using principles of balance and leverage.
  • Field Trip to Construction Sites: Take a family field trip to a construction site or any place where engineering is involved. Observe and discuss the use of cranes (pulleys), levers, and other simple machines.
  • Toy Engineering: Encourage families to explore engineering concepts through toys that involve simple machines. Building a toy car with wheels and axles or constructing a mini-bridge using blocks can be fun and educational.
  • Design and Build: Engage families in a design and build project where they create a model using simple machines. This could be a small playground, a toy that incorporates gears (another type of simple machine), or a lifting system.

​Learn more...

Sample Simple Machine Activities

  • Archimedes Screw Exploration from High Hill Education is a simple project using a plastic bottle that showcases how this invention made hundreds of years ago was able to move material.
  • Kids will get a kick out of moving toys from downstairs to upstairs using this Banister Pulley from Hands on As We Grow
  • Kids are sure to be impressed by this working elevator model that explores pulleys from How to Adult
  • Let your kids imaginations run wild as they make their own Button Wheel & Axel Cars from Almost Unschoolers
  • Pulley Experiment for Kids from 123 Homeschool 4 Me uses common household items like cans to make a fun-to-try simple machine
  • Simple machines and art collide in this fun Inclined Planes Art from Strong Start
  • Stack It Up! - Students analyze and begin to design a pyramid. They perform calculations to determine the area of their pyramid base, stone block volumes, the number of blocks required for their pyramid base, and make a scaled drawing of a pyramid on graph paper.
    Watch this activity on YouTube
  • Choosing a Pyramid Site - Working in engineering project teams, students choose a site for the construction of a pyramid. They base their decision on site features as provided by a surveyor's report; distance from the quarry, river and palace; and other factors they deem important to the project.​​
  • Launching Snowman from Buggy & Buddy is such a cute activity to help kids explore levers in a super creative way!
  • What can simple machines make? Take a peak with this Make a Crane from At Home with Ali
  • Wheel and Axle Project using plates from Sciencing is a fun, simple to make project with items you probably have laying around your house.
  • Simple and to the point Movable Pulley with Paper Clips from Carrots are Orange​
  • Paper Towel Roll Catapult from Kids Activities Blog is a mega size project showcasing the lever
  • This epic PVC Pipe Pulley from Little Bins for Little Hands is big in size, not in cost or difficulty to make!
  • Rolling Pin Pulley from Kids Activities Blog shows us that you don’t need anything fancy to make simple machines work
  • Tissue Box Catapult from Premeditated Leftovers is a fun twist on the typical lever project you’ve seen
  • Using Marbles to Experiment with Forces from Inclined Planes from The Techy Teacher turns discovering inclined planes into a game. Ready. Set. Learn!
  • What’s the Big Deal with a Fulcrum? from Ozark Ramblings is a simple, no frills look at a lever.​
  • This DIY Muscle Machine from KiwiCo is a fascinating project using pulleys.
  • I Spy Simple Machines from 123 Homeschool 4 Me is a free printable that not only teaches about simple machines, but gives instructions for a fun simple machines scavenger hunt too!
  • Bubble Machine Blower Machine from Teach Beside Me – this is such a fun idea kids will get excited about that explores the wheel simple machine
  • Lego Zipline from Little Bins for Little Hands is such a cool project to explore pulleys with kids
  • This easy to make pulley and lever board from Inspiration Labratories is the perfect introductory project to do indoors with kids of all ages!
  • Levers have never been more fun than when you create one out of recycled materials like The OT Toolbox
  • DIY Craft Stick Catapult is a fun-to-try activity learning about levers from Coffee Cups and Crayons
  • Make science come alive for kids with this Straw Roller coaster from Frugal Fun 4 Boys that explores inclined planes with kids!
  • Dive into history with this Ancient Civilization Irrigation Model that explores several simple machines from Teach Student Savvy
Click on image to view activity

More Simple Machine Videos
More Videos: Watch simple explanations of Simple Machines and related concepts. Click the link to browse through all study tools.

Key Words

  • Design: (verb): To plan out in systematic, often graphic form. To create for a particular purpose or effect. Design a building. (noun) A well thought-out plan.
  • Engineering: Applying scientific and mathematical principles to practical ends such as the design, manufacture and operation of efficient and economical structures, machines, processes and systems.
  • Force: A push or pull on an object.
  • Inclined plane: A simple machine that raises an object to greater height. Usually a straight slanted surface and no moving parts, such as a ramp, sloping road or stairs.
  • Lever: A simple machine that increases or decreases the force to lift something. Usually a bar pivoted on a fixed point (fulcrum) to which force is applied to do work.
  • Mechanical advantage : An advantage gained by using simple machines to accomplish work with less effort. Making the task easier (which means it requires less force), but may require more time or room to work (more distance, rope, etc.). For example, applying a smaller force over a longer distance to achieve the same effect as applying a large force over a small distance. The ratio of the output force exerted by a machine to the input force applied to it.
  • Pulley: A simple machine that changes the direction of a force, often to lift a load. Usually consists of a grooved wheel in which a pulled rope or chain runs.
  • Pyramid: A massive structure of ancient Egypt and Mesoamerica used for a crypt or tomb. The typical shape is a square or rectangular base at the ground with sides (faces) in the form of four triangles that meet in a point at the top. Mesoamerican temples have stepped sides and a flat top surmounted by chambers.
  • Screw: A simple machine that lifts or holds materials together. Often a cylindrical rod incised with a spiral thread.
  • Simple machine: A machine with few or no moving parts that is used to make work easier (provides a mechanical advantage). For example, a wedge, wheel and axle, lever, inclined plane, screw, or pulley.
  • Spiral: A curve that winds around a fixed center point (or axis) at a continuously increasing or decreasing distance from that point.
  • Tool: A device used to do work.
  • Wedge: A simple machine that forces materials apart. Used for splitting, tightening, securing or levering. It is thick at one end and tapered to a thin edge at the other.
  • Wheel and axle: A simple machine that reduces the friction of moving by rolling. A wheel is a disk designed to turn around an axle passed through the center of the wheel. An axle is a supporting cylinder on which a wheel or a set of wheels revolves.
  • Work: Force on an object multiplied by the distance it moves. W = F x d (force multiplied by distance).​
  • Complex machine: A machine that operates by combining two or more of the six simple machines.
  • Torque: The result of applying a linear force at the outside of a circular frame to create a turning tendency.​
  • Compound pulley: A compound pulley is a combination fixed and movable pulley system.
  • Differential
  • Fixed pulley: A fixed pulley is a simple machine that uses a wheel with a groove in it and a rope that fits into the groove. The other end of the rope attaches to a load , or the object you're needing to move.
  • Force: Force is a push or pull on an object that can cause acceleration, slow down, remain in place, or change shape. 
  • Friction: Force that slows or stops movement between two objects that are in contact with each other.
  • Fulcrum: A pivot point around which a lever turns 
  • Kinetic energy: The energy an object has because of its motion.​
  • Effort :The force applied to make the object move.
  • Load:  An amount of something carried. 
  • Mass: The amount of matter (i.e., electrons, protons and neutrons) an object contains.
  • Movable pulley: A movable or class 2 pulley has an axle that is "free" to move in space. A movable pulley is used to transform forces. A movable pulley has a mechanical advantage of 2. That is, if one end of the rope is anchored, pulling on the other end of the rope will apply a doubled force to the objects attached to the pulley.
  • Newtons First Law of Motion: The first law says that any object in motion will continue to move in the same direction and speed unless forces act on it.
  • Newtons Second Law of Motion: The second law states that the greater the mass of an object, the more force it will take to accelerate the object. There is even an equation that says Force = mass x acceleration or F=ma.
  • Third Law of Motion: The third law states that for every action, there is an equal and opposite reaction. This means that there are always two forces that are the same. 
  • Pivot:  A fixed point supporting something that turns or balances
  • Potential energy: The stored energy an object has because of its position or state.  
  • Rube Goldberg machine: A complex machine that is designed to carry out simple tasks. A Rube Goldberg machine works with a series of chain reactions that transfer energy through different pulleys, levels, cogs, and more to carry out one final task. 
  • Slope: Ground that is not level or flat.
  • Balanced Forces: These forces occur when two equivalent forces work in opposite directions on a surface. 
  • Unbalanced forces:  These forces occur when two forces act in opposite directions on a surface unequal in magnitude and size.

Concepts Related to Simple Machines

If your class is interested in studying simple machines and you choose to facilitate a simple machine investigation, consider using any 3 or 4 concepts listed below. Choosing a limited number of concepts based on children's interests helps to narrow down the research required by teachers. It also helps teachers shape the investigation by diving deeper into the chosen content instead of feeling pressure to cover all concepts related to the topic. Choosing what's most relevant to the children in your class helps everyone get the most out of the investigation. 
Work
Force + Force Reduction
Compound + Simple Machines
Mechanical Advantage
Gravity
Friction
​Newtons Laws of Motion
Power
Potential + Kinetic Energy
Balanced + Unbalanced Forces
​Inclined Plane
Lever
Wedge
Screw
Wheel + Axle
Pulley

Simple Machine Songs

Books about Simple Machines

Click on the link to purchase from Amazon.

Simple Machines Resources and References

https://www.ducksters.com/science/simple_machines.php
https://easyscienceforkids.com/all-about-simple-machines/
https://theproductiveteacher.com/physical-science/how-do-simple-machines-help-us-2/
https://www.ducksters.com/science/laws_of_motion.php
​https://www.123homeschool4me.com/
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