1. Levers and Pulleys Not so simple machines!

2. Just think….  Could you lift your science teacher in the air?

3. Keep Thinking….. (This means you don’t have to write this!!)  Building a house  Lifting a car  Building the pyramids  Handicap ramps  Paper cutters  Wheels on a car  What do all of these have in common?  They are use simple machines!

4. Important Definitions  Machine- device for doing work  Complex machines have motors, simple machines do not  Effort- the amount of force applied to a machine  Effort is measured in Newtons (N)

5. Types of Simple Machines  Lever  Pulley  Wheel and axle  Inclined plane  Wedge  Screw

6. Just Read… Simple machines have been used for thousands of years. They were even used to help build the pyramids!

7. Levers The most simple and most common simple machine.

8. 3 Parts of a lever

9. Class 1 Levers

10.  The fulcrum is located somewhere between the effort and the load  Examples include:  The claw of a hammer  crowbar

11. Double Class 1 Levers  Two levers working together form a double lever  Examples Include:  Scissors  Tin snips

12. Class 2 Levers

13.  Has a fulcrum at one end of the lever arm  Examples include:  Paper cutter  Wheelbarrow

14. Class 3 Levers

15.  In a class 3 lever, the fulcrum is at one end, and the effort is applies between the fulcrum and the load  Examples include:  Baseball bat  Fishing pole  Catapult

16. Wheel and Axle

18.  Can be an actual wheel and axle OR a bar that rotates around an axis  Examples include:  Steering wheel  A wrench turning a bolt (see levers and pulleys book page 7)  Windlass (crank used to raise a bucket, see page 8)  Handle of a faucet (page 8)

19. The Inclined Plane

21.  A sloped, flat surface, or ramp  One-part simple machine that does not move

22. Pulleys

24.  A pulley is a wheel that is free to turn on an axle  The wheel is called a sheave  A pulley is considered to be a variation of the lever  Pulleys can be fixed or movable