a ball hits and rebounds?

Question

A 0.5 kg ball hits a wall traveling in a positive direction at 5 m/s. It rebounds directly back from the wall at a speed of 5 m/s. Determine the change in momentum of this ball.
A {( kg*m)/s}*2.5
B {( kg*m)/s}*-2.5
C {( kg*m)/s}*5
D {( kg*m)/s}*-5

Answer 1

Step 1: Find initial momentum:
pi = mv = .5 * 5 = 2.5 kg*m/s

Step 2: Find final momentum:
pf = mv = .5 * -5 = -2.5 kg*m/s

Step 3:Find change in momentum:
Δp = pf - pi
Δp = -2.5 - -2.5
Δp = -5 kg*m/s