FCTC Pulleys, Gears, and Levers 4

Question 1

A bevel gear set is used primarily to accomplish which task?

Accepted Answer

Transmit power between shafts at an angle

Answer

Bevel gears are cone-shaped and designed to transmit motion between shafts that intersect at an angle, commonly 90 degrees.

Question 2

A scissors jack on a car is an example of which simple machine principle?

Accepted Answer

Lever and screw combination

Answer

A scissors jack uses a screw to force levers apart, combining lever and screw simple machines to multiply force and lift a vehicle.

Question 3

In a clock, why are gears of different sizes used together?

Accepted Answer

To control different speeds for hour, minute, and second hands

Answer

Different gear ratios in a clock cause the hour, minute, and second hands to rotate at precise, different speeds from the same power source.

Question 4

When the effort arm of a lever is shorter than the load arm, the lever provides which of the following?

Accepted Answer

Less force but greater speed and range

Answer

When the effort arm is shorter than the load arm, mechanical advantage is less than 1 — you apply more force but gain speed and distance.

Question 5

A worm gear is most commonly used to achieve which result?

Accepted Answer

Very large gear reductions in a compact space

Answer

Worm gears provide very high gear reduction ratios in a small package and are often self-locking, preventing back-driving.

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