FCTC FCTC Test Pulleys, Gears, and Levers Questions and Answers 5

Question 1

A lever in equilibrium has a 50 lb load 4 feet from the fulcrum. How much effort is needed 10 feet from the fulcrum on the opposite side?

Accepted Answer

20 lbs

Answer

Using the lever equation: effort × 10 = 50 × 4, so effort = 200 ÷ 10 = 20 lbs.

Question 2

Which scenario correctly describes an idler gear in a gear train?

Accepted Answer

It reverses the direction of rotation without changing the gear ratio

Answer

An idler gear placed between two gears reverses the direction of the driven gear without affecting the overall gear ratio.

Question 3

A snatch block is a type of pulley used in rigging. What makes it different from a standard pulley?

Accepted Answer

It can be opened to insert a rope without threading the end

Answer

A snatch block opens on the side so a rope can be inserted midway without needing access to the rope's end.

Question 4

If a first-class lever's effort arm equals its resistance arm, what is the mechanical advantage?

Accepted Answer

1

Answer

When effort arm = resistance arm, MA = effort arm ÷ resistance arm = 1, so no force multiplication occurs.

Question 5

A worm gear set has a worm with 1 start and a worm wheel with 40 teeth. What is the gear reduction ratio?

Accepted Answer

1:40

Answer

With a single-start worm, one full worm rotation advances the wheel by 1 tooth, so the ratio is 1:40.

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