WTMA Mechanical Comprehension 3

Question 1

A spring is compressed 3 inches by a 30-lb force. Following Hooke's Law, how much force is needed to compress it 5 inches?

Accepted Answer

50 lbs

Answer

Hooke's Law: force is proportional to displacement. The spring constant = 30/3 = 10 lb/in, so 5 in × 10 lb/in = 50 lbs.

Question 2

Which of the following is an example of a third-class lever?

Accepted Answer

A fishing rod

Answer

In a third-class lever the effort is between the fulcrum and the load, as in a fishing rod where the hand applies effort between the pivot point and the fish.

Question 3

Air pressure in a tire is measured in PSI. If the tire's internal volume decreases by half (without leaking), what happens to the pressure?

Accepted Answer

It doubles

Answer

Boyle's Law states that pressure and volume are inversely proportional at constant temperature, so halving the volume doubles the pressure.

Question 4

A block-and-tackle system uses two movable pulleys. What is its mechanical advantage?

Accepted Answer

4

Answer

Each movable pulley doubles the mechanical advantage, so two movable pulleys provide a mechanical advantage of 4.

Question 5

Two pipes carry water to a tank. Pipe A has a diameter of 2 inches and Pipe B has a diameter of 4 inches. At equal water pressure, which pipe delivers more water?

Accepted Answer

Pipe B, because a larger cross-section allows greater flow

Answer

Flow rate depends on cross-sectional area; Pipe B's area (πr²) is four times that of Pipe A, so it carries four times more water.

WTMA - Wiesen Test of Mechanical Aptitude Practice Test

WTMA - Wiesen Test of Mechanical Aptitude Practice Test

WTMA Mechanical Comprehension 3