1. Making WORK easier!

2. Types of Simple Machines
Pulley
Inclined Plane
Lever
Wheel and axle
Wedge
Screw

3. Why do we use them?
Machines make work easier (NOT less) by changing either the:
Size of the force
Direction of the force

4. 50 kg

5. M.A. = Fr Fe Mechanical Advantage
The number of times a machine multiplies your applied force is the ACTUAL mechanical advantge
Resistance Force (weight of object)
M.A. = Fr Fe
Effort Force (force YOU are supplying)
Mechanical Advantage

6. Resistance Force Fr
Effort Force Fe

7. Ideal Mechanical Advantage
The number of times a machine SHOULD multiply your applied force
I.M.A. = depends on type of machine
Ideal Mechanical Advantage

8. M.A. I.M.A. X 100 Efficiency = Efficiency
Measure of how much work put into a
machine is changed to useful work put out
by the machine.
M.A.
I.M.A.
X 100
Efficiency =

9. Work
Energy is conserved  in “ideal” machines, the work you put in is equal to the work the machines gives out
“Real” machines  you do MORE work than machines give back out
Why use them???
W = F·d
W = F·d

10. Parts of a lever Fe dr Fr de Resistance distance Fulcrum
Effort distance

11. Three classes of Levers
1st class lever
2nd class lever
3rd class lever

12. 1st class levers

13. 2nd class lever

14. 3rd class lever Mechanical Advantage is LESS than 1 Fulcrum
Effort Force
Mechanical Advantage is LESS than 1
Resistance Force

15. Which class lever?

16. IMA - Levers
The number of times a lever SHOULD multiply your applied force
I.M.A. = de dr
Effort distance
Resistance distance

17. Inclined plane
Wout = Fr·dr
Win = Fe·de Fe Fr

18. Ideal Mechanical Advantage - Inclined Plane
Big Bang Theory clip
IMA = L h L h

19. Works Cited