FCTC Test Applying Mechanical Reasoning Questions and Answers 5

Question 1

A fixed pulley is used to lift a 150 lb load. How much force must be applied to the rope?

Accepted Answer

150 lbs

Answer

A fixed pulley only changes the direction of force, not its magnitude; you must still pull with 150 lbs.

Question 2

Three resistors of 6 ohms each are connected in parallel. What is the total resistance of the circuit?

Accepted Answer

2 ohms

Answer

For equal resistors in parallel, total resistance = single resistance ÷ number of resistors = 6 ÷ 3 = 2 ohms.

Question 3

A gear train consists of three gears in series with 10, 20, and 40 teeth respectively. The first gear drives the second, and the second drives the third. If the first gear turns at 400 RPM, at what speed does the third gear turn?

Accepted Answer

100 RPM

Answer

First to second: 400 × (10/20) = 200 RPM; second to third: 200 × (20/40) = 100 RPM.

Question 4

A 10 lb object rests on a frictionless inclined plane at 30°. What is the component of gravity pulling the object down the slope?

Accepted Answer

5 lbs

Answer

The force along the slope = weight × sin(30°) = 10 × 0.5 = 5 lbs.

Question 5

Which of the following best describes the mechanical advantage of a wedge used to split wood?

Accepted Answer

MA = length ÷ width

Answer

The mechanical advantage of a wedge equals its length divided by its width — a longer, thinner wedge splits more easily.

FCTC Test Practice Test

FCTC Test Practice Test

FCTC Test Applying Mechanical Reasoning Questions and Answers 5