1. Machines & Efficiency

2. Simple Machines
In your notebook write down 5 machines you saw on your way to school today.

3. The 6 Simple Machines
Lever

4. The 6 Simple Machines
Pulley

5. The 6 Simple Machines
Inclined Plane

6. The 6 Simple Machines
Screw

7. The 6 Simple Machines
Wedge

8. The 6 Simple Machines
Wheel and Axle

9. Why do we need simple machines?
Machines DO NOT reduce the amount of work.
Work = Fd

10. Why do we need simple machines?
W= Fd
input
output

11. Why do we need simple machines?
Machines make work easier by changing the size or direction of the force.

12. The Inclined Plane
Force
distance

13. Levers Three parts to a lever: Load (output) Force (input) Fulcrum:
support or balance

14. A seesaw is a lever
The fulcrum acts as a pivot point, allowing the lever to rotate.

15. Three Lever Classes
1st Class Lever
Input
Output F

16. Three Lever Classes
2nd Class Lever
Output
Input F

17. Three Lever Classes
3rd Class Lever
Output
Input F

18. Three Lever Classes
2nd Class Lever
Input
Output F

19. Three Lever Classes
3rd Class Lever F
Input
Output

20. Three Lever Classes
1st Class Lever
Input
Output F

21. Mechanical Advantage
MA = Fo = Li
Fi Lo

22. Pulleys
By adding rope you decrease the input force needed to achieve the same amount of work

24. Mechanical Efficiency
Eff = _Wo_ X 100 Wi
Never more than 100%