Answer:
A) The correct answer is the first. The shock is elastic
B) For the momentum to be preserved the external force on the system must be zero
Explanation:
Part A
Let's analyze the problem, this is a case of collisions, if the eight ball is stuck, it is as if it had a very high mass, so the cue ball must bounce, since the collision is elastic
The correct answer is the first.
The shock is elastic
Part b
Momentum is preserved if the whole body system is isolated
For the momentum to be preserved the external force on the system must be zero