impulse and collisions I have one problem I've been trying to do, but I'm stuck on it. In this one, two ice skaters collide into each other. The specifics are as follows: Skater 1 (mass 58.96 kg) is travelling at 7.15 m/s. She then collides with skater 2 (mass 49.89 kg) who is at rest. During the collision, skater 1 pushes skater 2 as hard as she can, imparting an average force of 1300 N over a period of .75 seconds. The questions are how fast are skater 1 and skater 2 moving after the impact. I 've got the whole force over time thing is impulse, so I've got that (m1v1f + m2v2f) - (m1v1i + m2v2i) = 975 and breaking it down, collecting like terms, and inserting values I already know, it works out to 5896 v1f-49.89 v2f = 1396.564 Unfortunately, this formula still has 2 unknown values, and I can't think of a second formula to use to do substitution.