1. What is mechanical advantage?
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What is mechanical advantage?

2. Mechanical advantage is the amount of help that a machine gives you.
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Mechanical advantage is the amount of help that a machine gives you.

3. 5/8/2018
What is WORK?

4. Work occurs when a force moves an object over a distance.
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Work occurs when a force moves an object over a distance.

5. 5/8/2018
What is a FORCE?

6. A force is a PUSH or a PULL.
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A force is a PUSH or a PULL.

7. 5/8/2018
What is a PULLEY?

8. A pulley is a simple machine.
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A pulley is a simple machine.
It is made with a grooved wheel and a rope.

9. 5/8/2018
What is a GEAR?

10. 5/8/2018
A gear is a simple machine. It is a toothed wheel that meshes another toothed mechanism.
It can change the speed, direction, or amount of force needed to do work.

11. When the teeth of two gears are in contact with each other they are…
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When the teeth of two gears are in contact with each other they are…

12. 5/8/2018
Meshed

13. 5/8/2018
What are the names given to the first, middle and last gears in this Gear Train? ? ? ?

14. 5/8/2018
Idler

15. If the follower gear is moving faster, it is called…
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If the follower gear is moving faster, it is called…

16. 5/8/2018
Gearing Up

17. What direction is the follower gear moving in?
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What direction is the follower gear moving in?
Driver
Follower ?

18. Identify the following:
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Identify the following:
Gear
Teeth
Axle
Meshed Area

19. This is an example of what type of pulley system?
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This is an example of what type of pulley system?

20. A Movable Pulley System
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A Movable Pulley System
A movable  pulley  is a pulley that moves with the load.
The advantage of a movable pulley is that the effort needed to move the load is less than the weight of the load.
The disadvantage is that the load is moving in the same direction as the effort and this is not always convenient.

21. This is an example of what type of pulley system?
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This is an example of what type of pulley system?

22. The fixed pulley is attached to an unmovable object.
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A Fixed Pulley System
The fixed pulley is attached to an unmovable object. 
The advantage is that the direction of the effort needed to move the load is opposite to the load itself.
The disadvantage is that you have to apply the same effort to lift the load as the weight of the load.

23. This is an example of what type of pulley system?
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This is an example of what type of pulley system?

24. A Block and Tackle Pulley System
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A Block and Tackle Pulley System
The Block and Tackle pulley system is made up of two or more pulleys. 
The advantage is that the direction of the effort needed to move the load is opposite to the load itself.
Another advantage is that the effort needed to move the load is less than the weight of the load.

25. What type of pulley system does NOT give you mechanical advantage?
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What type of pulley system does NOT give you mechanical advantage?

26. 5/8/2018
A Fixed Pulley System

27. 5/8/2018
What is the effort needed to lift a load of 120N using this pulley system?

28. 5/8/2018
30 Newtons

29. Block and Tackle Pulley
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Match the following: 1
Fixed Pulley A
Movable Pulley B 2
Block and Tackle Pulley C 3

30. Match the following: Spur Gear Worm Gear Bevel Gear A 1 B 2 C 3
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Match the following: A
Spur Gear 1 B
Worm Gear 2
Bevel Gear C 3

31. 5/8/2018
What is different about the way gears on a bicycle turn in comparison to standard spur gears?

32. The gears turn in the same direction.
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The gears turn in the same direction.
Bicycles have sprocket and chain gears that work like some pulley systems. A chain connects the sprocket gears on the pedals to the back wheel. The chain also allows the gears to turn in the same direction. The sprockets keep the chain from slipping as it turns.

33. 5/8/2018
Why might a Block and Tackle pulley system be the best choice in this situation?

34. 5/8/2018
A Block and Tackle pulley is a good choice in this situation because the amount of effort needed is less which is good for heavy loads.
Also, the direction of the effort is opposite with a Block and Tackle pulley. It is easier to “pull down” in order to lift because you can have gravity help you.

35. Why was a movable pulley not a good choice in this example?
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Why was a movable pulley not a good choice in this example?

36. 5/8/2018
With a movable pulley the effort is in the same direction as the load. If the load is moving up, the person would need to pull up which would be awkward.

37. This is an example of gearing up.
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How many times would the follower gear rotate if the driver gear were to rotate 2 times?
This is an example of gearing up.
FOLLOWER
DRIVER

38. This is an example of gearing up.
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How many times would the driven gear rotate if the driver gear were to rotate 3 times?
This is an example of gearing up.
DRIVER
FOLLOWER

39. 5/8/2018
What is the effort needed to lift a load of 50N using this pulley system?

40. 5/8/2018
25 Newtons

41. 5/8/2018
What is the effort needed to lift a load of 400N using this pulley system?

42. 5/8/2018
200 Newtons

43. 5/8/2018
Fill in the blanks:
A gear train can change the _______, _______, or amount of _______needed to do work.
A pulley system can change the _______ of effort and the _______ of effort needed to move a load.