1. Work & Simple Machines

2. Define / Describe WORK

3. Define / Describe WORK
Work is done when a force causes an object to move in the direction that the force is applied.
The formula for work is: W = F X D
If there is no movement, there is no work

4. Two things must happen for work to be done. What are they?

5. Two things must happen for work to be done. What are they?
A force must be applied to an object
The object must move in the same direction as the force

6. What is the purpose of a machine?

7. What is the purpose of a machine?
to make work easier

8. How do machines make work easier?

9. How do machines make work easier?
They can change the amount of force
They can change the distance
(Remember that Work = Force X Distance)
They can also change the direction

10. What are the 6 types of simple machines?

11. What are the 6 types of simple machines?
There are three simple machines:
The lever, the pulley, and the inclined plane The wheel and axle, the wedge, and the screw are modifications of these simple machines.

12. What is a compound (or complex) machine?

13. What is a compound (or complex) machine?
A machine made up of two or more simple machines.

14. Describe LEVER

15. Describe LEVER
A lever is a simple machine made with a rigid bar free to pivot (move) around a fixed point called a fulcrum

16. Describe the 3 types of levers:

17. Describe the 3 types of levers:
A first class lever is like a teeter-totter or see-saw. One end will lift an object (child) up just as far as the other end is pushed down.
A second class lever is like a wheel barrow. The long handles of a wheel barrow are really the long arms of a lever.
A third class lever is like a fishing pole. When the pole is given a tug, one end stays still but the other end flips in the air catching the fish.
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18. Diagrams of Levers
Effort force = input force
Load = output force

19. Diagrams of Levers

20. Describe PULLEYS

21. Describe PULLEYS
A pulley is a simple machine made with a rope, belt or chain wrapped around a grooved wheel. A pulley works two ways.

22. How does a pulley work? A pulley works two ways.
It can change the direction of a force or it can change the amount of force.

23. What are the types of pulleys?

24. What is an inclined plane?

25. What is an inclined plane?
An inclined plane is a simple machine with no moving parts. It is simply a straight slanted surface.

26. Diagram of Inclined Plane

27. What is a wheel and axle?

28. What is a wheel and axle?
A wheel and axle is a modification of a pulley. A wheel is fixed to an axle.
The wheel and axle must move together to be a simple machine.
Sometimes the wheel has a crank or handle on it.
Examples of wheel and axles include roller skates and doorknobs.

29. Diagram of Wheel & Axle

30. What is a wedge?

31. What is a wedge?
A wedge is a modification of an inclined plane that moves. Used to cut!
It is made of two inclined planes put together.

32. Diagram of Wedge
simplemachines.html

33. What is a screw?

34. What is a screw?
A screw is a simple machine that is like an inclined plane.
It is an inclined plane that wraps around a cylinder.
Used to hold things together!

35. Diagram of Screw