1. Mr. King’s Science Classes
Simple Machines
Mr. King’s Science Classes

2. Introduction Simple machines are machines with few or no moving parts.
There are 7 main Simple Machines.

3. Kinds of Simple Machines
We will be learning about the seven simple machines. They are:
1. Lever
2. Inclined Plane
3. Wedge
4. Screw
5. Wheel and Axle
6. Pulley
7. Gears

4. Energy and Work
Suppose you needed to move an object. You might use tools to help you. Simple machines are tools that use energy to do work.
Energy is the ability to do work.
You probably have used several of the seven kinds of simple machines.

5. 1. What is a Lever? A hammer is a lever that helps do work.
Work is done whenever force makes an object move.

6. There are 3 different kinds or “classes” of levers.
First Class Lever

7. First Class Lever
force

8. First Class Lever
force
fulcrum

9. First Class Lever
force
fulcrum
weight

10. First Class Lever
By moving the fulcrum, the dynamics of the lever change. Here is how:
force
fulcrum
weight

11. First Class Lever
By moving the fulcrum, the dynamics of the lever change. Here is how:
force
fulcrum
weight
Requires more force to move the weight but less distance

12. First Class Lever
By moving the fulcrum, the dynamics of the lever change. Here is how:
force
fulcrum
weight
Requires more force to move the weight but less distance

13. First Class Lever
By moving the fulcrum, the dynamics of the lever change. Here is how:
force
fulcrum
weight
Requires more force to move the weight but less distance

14. First Class Lever
By moving the fulcrum, the dynamics of the lever change. Here is how:
force
fulcrum
weight
Requires more force to move the weight but less distance

15. First Class Lever
By moving the fulcrum, the dynamics of the lever change. Here is how:
force
fulcrum
weight
Requires more force to move the weight but less distance

16. First Class Lever
By moving the fulcrum, the dynamics of the lever change. Here is how:
force
fulcrum
weight
Requires more force to move the weight but less distance
The weight moves a greater distance than the force.

17. First Class Lever
By moving the fulcrum, the dynamics of the lever change. Here is how:
force
fulcrum
weight
Requires more force to move the weight but less distance
The weight moves a greater distance than the force.

18. First Class Lever
By moving the fulcrum, the dynamics of the lever change. Here is how:
Now, move the fulcrum clear to the right and notice the difference.
force
fulcrum
weight

19. First Class Lever
By moving the fulcrum, the dynamics of the lever change. Here is how:
Now, move the fulcrum clear to the right and notice the difference.
force
fulcrum
weight

20. First Class Lever
By moving the fulcrum, the dynamics of the lever change. Here is how:
Now, move the fulcrum clear to the right and notice the difference.
force
fulcrum
weight

21. First Class Lever
By moving the fulcrum, the dynamics of the lever change. Here is how:
Now, move the fulcrum clear to the right and notice the difference.
force
fulcrum
weight

22. First Class Lever
By moving the fulcrum, the dynamics of the lever change. Here is how:
Now, move the fulcrum clear to the right and notice the difference.
force
fulcrum
weight

23. First Class Lever
By moving the fulcrum, the dynamics of the lever change. Here is how:
Now, move the fulcrum clear to the right and notice the difference.
force
fulcrum
weight
Now you have just the opposite, less force to move the weight but more distance.

24. First Class Lever
By moving the fulcrum, the dynamics of the lever change. Here is how:
Now, move the fulcrum clear to the right and notice the difference.
force
fulcrum
weight
Now you have just the opposite, less force to move the weight but more distance.

25. First Class Lever
By moving the fulcrum, the dynamics of the lever change. Here is how:
Now, move the fulcrum clear to the right and notice the difference.
force
fulcrum
weight
Now you have just the opposite, less force to move the weight but more distance.

26. First Class Lever
By moving the fulcrum, the dynamics of the lever change. Here is how:
Now, move the fulcrum clear to the right and notice the difference.
force
fulcrum
weight
Now you have just the opposite, less force to move the weight but more distance.

27. First Class Lever
By moving the fulcrum, the dynamics of the lever change. Here is how:
Now, move the fulcrum clear to the right and notice the difference.
force
fulcrum
weight
Now you have just the opposite, less force to move the weight but more distance.

28. First Class Lever
By moving the fulcrum, the dynamics of the lever change. Here is how:
Now, move the fulcrum clear to the right and notice the difference.
force
fulcrum
weight
The weight does not move very much.
Now you have just the opposite, less force to move the weight but more distance.

29. Can you guess what would be the dynamics if the fulcrum was directly in the middle?

30. Just a change in direction
Can you guess what would be the dynamics if the fulcrum was directly in the middle?
Just a change in direction

31. Now for the 2nd class lever.
How would changing the position of the weight change the dynamics of this lever?
force
fulcrum
weight

32. Now for the 3rd class lever.
How would changing the position of the force change the dynamics of this lever?
force
fulcrum
weight

33. 2. What is an Inclined Plane?
A ramp is an inclined plane.
A ramp helps move objects.
You can use an inclined plane to help move an object to a higher or lower place.

34. What is the mechanical advantage of the ramp or incline plane?
force
What do you notice about the difference between these two ramps?
weight

35. What is the mechanical advantage of the ramp or incline plane?
force
What do you notice about the difference between these two ramps?
weight

36. What is the mechanical advantage of the ramp or incline plane?
force
What do you notice about the difference between these two ramps?
weight

37. What is the mechanical advantage of the ramp or incline plane?
force
What do you notice about the difference between these two ramps?
weight

38. What is the mechanical advantage of the ramp or incline plane?
force
What do you notice about the difference between these two ramps?
weight

39. What is the mechanical advantage of the ramp or incline plane?
force
What do you notice about the difference between these two ramps?
weight

40. What is the mechanical advantage of the ramp or incline plane?
force
What do you notice about the difference between these two ramps?
weight

41. What is the mechanical advantage of the ramp or incline plane?
force
What do you notice about the difference between these two ramps?
weight

42. What is the mechanical advantage of the ramp or incline plane?
force
What do you notice about the difference between these two ramps?
weight
What is the trade off between these two ramps?

43. 3. What is a Wedge? A doorstop is a wedge.
A wedge is a simple machine used to push objects apart.
An ax is a wedge that splits wood.
A wedge could be considered a two sided incline plane.

44. 4. What is a Screw?
A screw is a simple machine used to hold objects together.
Think about your desk.
Does it have screws helping to hold it together?
A screw is an incline plane twisted on itself.

45. 5. What is a Wheel and Axle?
A wheel and axle is a simple machine made of a rod attached to the center of a wheel.
The axle, or rod, turns when you put force on the wheel.
You probably have seen a wheel and axle on scooters, cars, roller skates, and wagons.

46. 6. What is a Pulley?
A pulley is a simple machine with a wheel and with a rope.
The rope fits around the edge of the wheel.
You can use a pulley to move a load up, down or sideways.

47. How do Pulleys Work? They can change direction of the load. force
weight

48. OR How do Pulleys Work? They can change direction of the load. force
weight OR

49. How do Pulleys Work?
Using two different pulleys, with the weight attached to the bottom one with give you a mechanical advantage.
force
weight

50. How do Pulleys Work?
Using two different pulleys, with the weight attached to the bottom one with give you a mechanical advantage.
force
weight
This is called a block and tackle. You will use less force to lift the weight but will have to pull more rope.

51. How do Pulleys Work?
Using two different pulleys, with the weight attached to the bottom one with give you a mechanical advantage.
force
weight
This is called a block and tackle. You will use less force to lift the weight but will have to pull more rope.

52. How do Pulleys Work?
Using two different pulleys, with the weight attached to the bottom one with give you a mechanical advantage.
force
weight
This is called a block and tackle. You will use less force to lift the weight but will have to pull more rope.

53. How do Pulleys Work?
Using two different pulleys, with the weight attached to the bottom one with give you a mechanical advantage.
force
weight
This is called a block and tackle. You will use less force to lift the weight but will have to pull more rope.

54. How do Pulleys Work?
Using two different pulleys, with the weight attached to the bottom one with give you a mechanical advantage.
force
weight
This is called a block and tackle. You will use less force to lift the weight but will have to pull more rope.

55. 7. What is a Gear?
Two toothed wheels fit together either directly or through a chain or belt.
Some gears may have a screw or a toothed shaft in place of one of the wheels.
A gear may also be a combination of toothed wheels that produces a certain speed like in a bicycle.

56. What This Means Simple machines are important to us in our daily life.
They help us do work.
They make our lives easier.