1. The problem statement, all variables and given/known data Values from previous problem: Pre-collision: v2kg=6m/s -->, v3kg=3m/s <-- Post-collision: v2kg=2m/s <--, v3kg=5.67m/s --> Collision time: 0.2 sec 2. Relevant equations F=mA=m(Δv/Δt) 3. The attempt at a solution My instinct to solve this was to use the pre-collision values to find out the forces each puck had on each other, because it seems like post-collision values for velocity would be irrelevant because the pucks are no longer having any force on each other. So, I did the following... Force of 2kg puck on 3kg puck: F=2kg(6m/s / 0.2 sec) = 60N Force of 3kg puck on 2kg puck: F=3kg(3m/s / 0.2 sec) = 45N Is this the correct way to approach this problem? Thanks for your help!