Physics + Engineering
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.
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.
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.
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.
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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.
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.
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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.
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..
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.
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.
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
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
- Open the drawer to get a pencil, what are you doing? (Push/Pull)
- Rolling a ball (Push/Pull)
- Press on the wall (Push/Pull)
- Drawing a bucket of water from well (Push/Pull)
- When you High Five with your friend (Push/Pull)
- When you are raising the bottom of the book in the air, what are you doing? (Push/Pull)
- 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.
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.
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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.
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.
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.
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.
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.
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.
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.
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!
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.
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!
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.
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.
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
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?
Can you think of examples of levers we use at home?
How does a seesaw work as a lever?
Can you find a pulley at home or in your neighborhood?
How do pulleys make lifting things easier?
Can you find examples of inclined planes in our home or community?
How does an inclined plane make it easier to move things?
Can you find objects at home that have wedge shapes?
How do wedges help us in our daily lives?
Where can you find screws in your home?
How do screws help hold things together?
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?
- General Understanding:
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:
Can you think of examples of levers we use at home?
How does a seesaw work as a lever?
- Pulley:
Can you find a pulley at home or in your neighborhood?
How do pulleys make lifting things easier?
- 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:
Can you find objects at home that have wedge shapes?
How do wedges help us in our daily lives?
- Screw:
Where can you find screws in your home?
How do screws help hold things together?
- 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...
- Inventors of Tomorrow-Simple Machines
- Hub Pages-Inventions and Simple Machines Presentations and Field Trip Ideas
- See the Edheads website for an interactive game on simple machines
- Simple Machines Handbook