A rocket is fired in space. As it moves, the total momentum of the rocket and its exhaust gases
A) decreases.
B) remains the same.
C) increases.
D) Any of the choices could be correct, depending on the nature of the rocket.

Question

Quizplus · Accepted Answer

According to the law of conservation of momentum, the total momentum of a system remains constant in the absence of external forces. In this case, the rocket and its exhaust gases are the components of the system. The rocket expels gas at high velocity in one direction, causing it to experience an equal and opposite force in the opposite direction. This means that the momentum of the gas is equal and opposite to the momentum of the rocket. Therefore, the total momentum of the system (rocket + gas) remains constant, and so option B is correct.

A Rocket Is Fired in Space