Question

Bodies A and B have equal mass. Body B is initially at rest. Body A collides with body B in a one–dimensional elastic collision. Which statement is true?
Body A comes to rest.

The momentum of the system is not conserved.
The kinetic energy of the system is not conserved.
The final velocity of body B is twice the initial velocity of body A.

Answer 1

Body A comes to the rest as this criteria can only conserve the momentum .. keep one thing in mind velocities get exchanged when there is a perfect elastic collision that to the masses have to be same

Answer 2

Answer:

Body A comes to rest.

Explanation:

If two objects collide and one of them was at rest and have the same mass, what will happen is that the one that was at rest will absorbe the kinetic energy of the system, and start moving with the same initial velocity of Body A.