A shell explodes into two fragments,one fragment 25 times heavier than the other.If any gas from the explosion has negligible mass,then
A) the momentum change of the lighter fragment is 25 times as great as the momentum change of the heavier fragment.
B) the momentum change of the heavier fragment is 25 times as great as the momentum change of the lighter fragment.
C) the momentum change of the lighter fragment is exactly the same as the momentum change of the heavier fragment.
D) the kinetic energy change of the heavier fragment is 25 times as great as the kinetic energy change of the lighter fragment.
E) the kinetic energy change of the lighter fragment is 25 times as great as the kinetic energy change of the heavier fragment.

Question

Quizplus · Accepted Answer

The law of conservation of momentum states that the total momentum of a closed system is constant if no external forces act on it. In the case of the shell explosion, the system is the two fragments. Since they are part of the same system and no external forces are considered, the momentum change of one fragment must be equal and opposite to the momentum change of the other, regardless of their masses. This means the momentum change of the lighter fragment is exactly the same as the momentum change of the heavier fragment, but in the opposite direction.

A Shell Explodes into Two Fragments,one Fragment 25 Times Heavier