A ball with original momentum of +4.0 kg*m/s hits a wall and bounces straight back without losing any kinetic energy. The change in momentum of the ball is?
p (momentum) = mv
Impulse = change in p/change in t
The Attempt at a Solution
I thought that if the KE was conserved, then momentum had to be conserved to, so needless to say, I am confused. Any help would be appreciated!