a rubber ball is thrown against a horizontal wall and bounces back with the same speed it came in at. The change in momentum vector of the ball is


A) 10 m/s^2

B) in the same directions the ball's initial motion

C) in the opposite direction as the ball's initial motion

D) zero

The units of A) are acceleration, m/s^2 , not momentum which is mass * velocity so NO WAY

If it reversed direction of velocity without changing sign of momentum
then
obviously it came back with NEGATIVE MASS !
so NO WAY

C) well all right

D ) LOL, it was thrown at zero speed ? Perhaps the mass was zero?

The change in momentum vector of the ball is D) zero.

When the ball bounces back with the same speed it came in at, it means that the ball's velocity reverses direction. However, since momentum is a vector quantity that depends on both the magnitude and direction of an object's velocity, a velocity reversal will result in a change in sign of the momentum vector. Thus, the change in momentum vector is zero because its magnitude remains the same but its direction changes.

To determine the change in momentum vector of the ball after bouncing against the horizontal wall, we need to consider the law of conservation of momentum. According to this law, the total momentum in a system remains constant unless acted upon by an external force.

In this case, when the rubber ball is thrown against the horizontal wall, it exerts a force on the wall and experiences an equal and opposite force from the wall. As a result, the ball's momentum changes in magnitude but not in direction.

Since the ball bounces back with the same speed it came in at, this means that its final velocity is equal in magnitude but opposite in direction to its initial velocity. Consequently, the change in momentum vector is in the opposite direction as the ball's initial motion.

Therefore, the correct answer is:

C) in the opposite direction as the ball's initial motion.