Pulleys
What are the two parts of a pulley?
- grooved wheel
- rope
A pulley that is attached to a support is called what?
fixed pulley
wheel; teeth
The standard type of gear is called a _____ _____.
spur gear
The pedals on a bike are the called the _____, and they are attached to the _____ gear.
crank; driver
Name three objects that use pulleys.
Answers will vary.
(crane, elevator, flagpole, clothesline, etc.)
A pulley that is attached to the load is called what?
movable pulley
Name three objects that use gears.
Answers will vary.
(bikes, clocks, cars, etc.)
What gear would you use if you wanted both the driver gear and the driven gear to move in the same direction?
idler gear
The chain works like a _____ to attach the front driver gear to the rear _____ gear, to make the gears rotate.
pulley; driven
What is a compound pulley?
A pulley system with two or more pulleys in it.
direction of force
Multiple gears are _____ together to make a _____ _____, and they always turn in _____ directions.
meshed; gear train; opposite
_____ gears are slanted and change the _____ of movement?
bevel; direction
What is the input component on a bike? What is the output component?
input - pedals; output - rear wheel
Why would someone use a compound pulley system with a fixed pulley and a movable pulley?
- to decrease the effort
- change the direction of force
Does a movable pulley change the direction of the force, or the amount of effort?
amount of effort
What is it called when we see how gears turn in comparison to other gears in the same system?
gear ratio
A _____ gear has only one tooth that goes in a _____.
worm; spiral
If you were to ride your bike uphill, you would put your bike in _____ gear. If you were to ride on flat ground, you would put your bike in _____ gear. If you were to ride your bike downhill, you would put your bike in _____ gear.
low; medium; high
What is it called when movable pulleys decrease the amount of effort needed?
mechanical advantage
In a fixed and movable compound pulley system:
- how much would the force of effort change?
- how far would you have to pull the rope?
- half the effort
- twice as far
If the driver gear has 40 teeth, and the driven gear has 10 teeth, what is the gear ratio?
1:4
The _____ _____ _____ is a flat, straight piece with teeth that mesh with a spur gear.
rack and pinion
How many speeds are on a bike that has 3 driver gears and 7 driven gears?
21
(3x7=21)