Part A

Answer:

v' = -18 m/s

Explanation:

• Assuming no external forces act during the collision, the overall momentum must be preserved as follows:

• The initial momentum can be defined this way (with the initial direction of the ball considered positive):

• The final momentum can be formulated as follows (given that v'b moves in the opposite direction to vb):

• If we consider that Mc >> mb, we assume the car's speed remains unchanged as a result of the collision, allowing us to substitute V'c for Vc in (3).
• Consequently, we can rewrite (3) like this:

• By substituting (2) and (4) back into (1), we arrive at:

• By simplifying and rearranging, we can solve for v'b like this:
• , which makes sense because it's as though the ball collided with a wall and simply reversed its velocity post-collision.