1. The problem statement, all variables and given/known data A ball with momentum of 10 kg-m/s [E] hits an object and rebounds with momentum of 6 kg-m/s [W]. What was the change in momentum? 2. Relevant equations delta p=p(final)-p(initial) 3. The attempt at a solution delta p=p(final)-p(initial) delta p=(6 kg-m/s)-(10 kg-m/s) delta p= -4 kg-m/s This problem seems so simple, and yet it's in the middle of a worksheet full of really hard problems, so I just wanted to make sure I'm doing it right.