1. The number of times a machine multiplies your effort force.
Mechanical Advantage
The number of times a machine multiplies your effort force.

2. Mechanical Advantage
Example: If you push on the handle of a car jack with a force of 30 lbs and the jack lifts a 3000 lb car, what is the jack’s mechanical advantage?
The jack multiplies your effort force by 100 times

3. What type of Simple Machine is a Car Jack?

4. Lever
A lever is a rigid bar that rotates around a fixed point called the fulcrum.
The bar may be either straight or curved.
In use, a lever has both an effort (or applied) force and a load (resistant force).

5. Lever Mechanical Advantage Formula: Input Force / Output Force
Output =R Input =E

6. 1st, 2nd and 3rd class levers

7. Now it’s your turn Answer these questions:
What is the name of your lever?
What Class is your lever?
Why is your lever used?
What is the Mechanical Advantage?
Draw your tool and label your measurements

8. 3 Classes of Levers
The class of a lever is determined by the location of the effort force and the load relative to the fulcrum

9. Examples: 1st class levers: scissors, pliers, seesaw
2nd Class Levers: Wheelbarrow, bottle opener

10. Examples
3rd Class Lever: arm, tongs, mouse trap, bb bat

11. Mechanical Advantage Inclined Plane

12. Mechanical Advantage Formula Inclined Plane
Output Force/ Input Force
Slope/ Height

13. Answer these questions:
Name of Inclined Plane
Why is it used? MA
Draw and Label

14. Mouse Trap Lets put together Mouse Trap
On a piece of paper label the Levers and Wedges.
Figure out the Mechanical Advantage
It this compound saving us any effort?

15. Wedge
Mechanical Advantage of Wedge: Divide the Length of the Slope by the thickness of the width.
Output Force/ Input Force

16. Name of Wedge
Why its used MA
Draw and label

17. Screw
Mechanical Advantage: circumference of the top divided by the pitch of the threads.
Pitch's are the distances between threads.

18. Screw
What is the name of your screw
Why is it used? MA
Draw and label

19. Wheel and Axle
The mechanical advantage of a wheel and axle is the ratio of the radius of the wheel to the radius of the axle.

20. Wheel and Axle
In the wheel and axle illustrated in the previous slide, the radius of the wheel is five times larger than the radius of the axle. Therefore, the mechanical advantage is 5:1 or 5.

21. Answer the Questions: Name of Wheel and Axle Why is it used? MA
Draw and Label

22. Gears and Wheel and Axles
Each gear in a series reverses the direction of rotation of the previous gear. The smaller gear will always turn faster than the larger gear.

23. Pulleys Fixed Pulley Movable Pulley
A fixed pulley changes the direction of a force; however, it does not create a mechanical advantage
The mechanical advantage of a moveable pulley is equal to the number of ropes that support the moveable pulley.

24. When you slip on ice, your foot kicks paddle (A),
lowering finger (B), snapping turtle (C) extends neck
to bite finger, opening ice tongs (D) and dropping pillow (E),
thus allowing you to fall on something soft.