Pulleys & Gears

Suppose the first gear in a system has 12 teeth. How many teeth should the second gear have, if you want the second gear to turn half as fast as the first gear?

• 6

• 24

• 12

• 36

Tags

NGSS.MS-PS2-2

The more teeth that there are on the second gear, the less it turns.

• True

• False

When gears have the same number of teeth, one of them will turn more than the other.

• True

• False

Why do you think oil is put on the chains of bicycles?

• a) The oil reduces the friction, which makes it easier to ride.

• b) Oil makes the sprocket shine

• c) The chains rub against the sprockets, which would cause both of them to wear down over time.

• Both A and C

In a fixed pulley, the direction of the effort is where?

• up

• down

• left

• right

Which of the following decreases when an object is lifted using a movable pulley?

• The distance the object moved
• The amount of force needed
• The length of the pulley’s rope
• The pull of gravity on the object

In a move-able pulley, the direction of the effort force is where?

• Down

• Up

• Left

• Right

There are three types of pulleys: fixed, movable, and combined.

• True

• False

Tags

NGSS.MS-PS2-2

Bonus question: What is different about the way gears on a bicycle turn in comparison to regular spur gears?

• a) Standard spur gears turn in opposite directions.

• b) Sprockets on a bike are not meshed and both turn in the same direction using the chain

• c) There's nothing different about it.

• Both a and b

Bonus question: Which gear would be best for travelling the fastest on flat ground?

• High gear would be best.

• Low gear would be best.