WTMA Force, Motion, and Friction 3

Question 1

A 5 kg object accelerates at 4 m/s². What is the net force acting on it?

Accepted Answer

20 N

Answer

Using Newton's second law: F = ma = 5 kg × 4 m/s² = 20 N.

Question 2

Two workers push a crate from opposite sides with equal force. What is the result?

Accepted Answer

The crate does not move

Answer

Equal and opposite forces produce a net force of zero, so the crate remains stationary (assuming it was at rest).

Question 3

A sled slides down a snowy hill and reaches the flat ground. What eventually stops it on the flat?

Accepted Answer

Friction between sled runners and snow

Answer

Friction between the sled runners and the snow acts opposite to the direction of motion, gradually decelerating the sled to a stop.

Question 4

Which scenario shows Newton's third law of motion in action?

Accepted Answer

A rocket expels gas downward and rises upward

Answer

A rocket demonstrates Newton's third law: the action of expelling gas downward produces an equal and opposite reaction force upward.

Question 5

A wrench handle is extended by adding a longer handle. How does this affect the force needed to turn a bolt?

Accepted Answer

Less force is needed

Answer

A longer handle increases the moment arm (torque), allowing the same bolt to be turned with less applied force.

WTMA - Wiesen Test of Mechanical Aptitude Practice Test