Answer
The change in the ball's momentum is $-20.0~kg~m/s$
Work Step by Step
We can find the change in velocity:
$\Delta v = v_f-v_0 = (-2.0~m/s)-(2.0~m/s) = -4.0~m/s$
We can find the change in the ball's momentum:
$\Delta p = m~\Delta v$
$\Delta p = (5.0~kg)(-4.0~m/s)$
$\Delta p = -20.0~kg~m/s$
The change in the ball's momentum is $-20.0~kg~m/s$.
