A space vehicle of mass m has a speed v. At some instant, it separates into two pieces, each of mass 0.5m. One of the pieces is at rest just after the separation.
-Which one of the following statements concerning this situation is true?
A)The moving piece has speed 2v.
B)This process conserves kinetic energy.
C)The piece at rest possesses kinetic energy.
D)The process does not conserve total energy.
E)This process does not conserve momentum.

Question

Quizplus · Accepted Answer

The total momentum before separation is mv. After separation, the piece at rest has zero momentum, so the moving piece must have momentum mv to conserve momentum. Since its mass is 0.5m, its speed must be 2v.

A Space Vehicle of Mass M Has a Speed V