1. Simple Machines Outline Notes
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2. There are 6 basic kinds of simple machines: the inclined plane, the wedge, the screw, the lever, the wheel and axle, and the pulley.

3. 1. Inclined Plane
Inclined plane: flat, sloped surface
Example: ramp

4. A. How It Works
Allows you to exert you input force over a longer distance

5. B. Mechanical Advantage
You can determine the ideal mechanical advantage of an inclined plane by dividing the length of the incline by its height.
Ideal mechanical advantage = length of incline ÷ height of incline

6. 2. Wedge
Wedge: device that is thick at one end and tapers to a thin edge at the other end.
Examples: zipper, knife

7. A. How It Works
Input forces exerted on a wedge causes the output forces to push the wedge into the object.

8. B. Mechanical Advantage
The ideal mechanical advantage of a wedge is determined by dividing the length of the wedge by its width.
The longer and thinner a wedge is, the greater its mechanical advantage.

9. 3. Screws Screw: inclined plane wrapped around a cylinder
Examples: threads in a jar lid, bolt

10. A. How It Works
Threads of a screw act like an inclined place to increase the distance over which you exert the input force

11. B. Mechanical Advantage
The ideal mechanical advantage of a screw is the length around the threads divided by the length of the screw.

12. 4. Levers
Lever: rigid bar that is free to pivot or rotate on a fixed point
Fulcrum: fixed point that a lever pivots around

13. A. How It Works
When you push down, you exert an input force on the handle which pivots on the fulcrum.

14. B. Mechanical Advantage
The ideal mechanical advantage of a lever is determined by dividing the distance from the fulcrum to the input force by the distance from the fulcrum to the output force.
Ideal mechanical advantage = distance from fulcrum to input force
÷ distance from fulcrum to output force

15. C. Different Types of Levers
1st class: always change the direction of the input force
2nd class: increase force but do not change the direction of the input force
3rd class: increase distance but do not increase the direction of the input force

16. 5. Wheel and Axle
Wheel and axle: simple machine made of 2 circular objects fastened together that rotate about a common axis
Examples: screw driver, doorknob

17. A. How It Works
Increases to your force but you must exert your force over a long distance.

18. B. Mechanical Advantage
You can find the ideal mechanical advantage of a wheel and axle by dividing the radius of the wheel by the radius of the axle.
Mechanical advantage = radius of wheel ÷ radius of axis

19. 6. Pulley
Pulley: simple machine made of a grooved wheel with a rope or cable wrapped around it

20. A. How It Works You use a pulley by pulling on one end of the rope.
Pulleys can decrease the amount of input force needed to lift an object or it can change the direction of your input force.

21. B. Types of Pulleys
There are 3 types of pulleys: a fixed pulley (attached to a structure), a moveable pulley (attached to the object you are moving), and a block and tackle (combination of a fixed an a moveable pulley).
The ideal mechanical advantage of a pulley is equal to the number of sections of rope that support the object.

22. 7. Simple Machines in the Body

23. A. Living Levers
Most of the machines in your body are levers that consist of bones and muscles.

24. B. Working Wedges
Your teeth are wedges

25. 8. Compound Machines
Compound machine: machine that utilizes 2 or more simple machines
The ideal mechanical advantage of a compound machine is the product of the individual ideal mechanical advantages of the simple machines that make it up.