1. Simple Machines
Physics Mr. Berman

2. What are some simple machines?
Lever
Incline Plane
Pulley

3. Simple Machines
Multiply the effort force (allows you to use a smaller effort force to raise a heavier object).
Change the direction of the force.
Do not reduce the work input.

4. Archimedes: ”GIVE ME A PLACE TO STAND AND I WILL MOVE THE EARTH”

5. Lever

6. Mechanical Advantage MA= Output Force(Weight of Object)
Input Force (Effort)
MA shows how much you are multiplying your effort force.

7. What is the trade off?
What happens to the effort distance, when a machine multiplies the effort force?
Answer: Effort distance increases

8. Ideal Mechanical Advantage
IMA= Effort Distance (din )
Output Distance (dout )
IMA is equal to MA in the absence of friction (ideal case).

9. IMA for a Lever IMA= Effort Distance = Effort Arm
Output Distance Load Arm

10. Problem What is the ideal mechanical advantage of the lever shown?
IMA=3
Load
Fulcrum
Effort

11. Lever

12. Types of Levers
Type1
Type 2
Type 3

13. Incline Plane

14. dOUT
dIN

15. Problem: Which has a greater IMA?

16. Problem: Find the IMA.
10m 5m

17. Pulleys

18. Pulleys

19. Single Fixed Pulley Ideally: Win=Wout Findin= Foutdout
IMA= din /dout =1

20. Single Moveable Pulley
IMA= 2

21. Combination of Fixed and Moveable Pulleys
IMA= 2

22. IMA for Pulleys
The IMA of pulleys can quickly be found by counting the number of lifting strands.

23. Question
What is the IMA of the following pulleys?

24. Efficiency
Efficiency indicates the percentage of the input work that was converted to useful work and not lost to friction.
% eff = (Wout / Win) x 100 %
% eff = (MA / IMA) x 100 %