Two figure skaters, one weighing 635N and the other 735N, push off against each other on very smooth ice.

a) If the heavier skater (735N) travels at 1.6m/s, how fast will the lighter one travel? Express your answer in m/s.

b) How much kinetic energy is "created" during the skaters' maneuver? Express your answer in joules.

c) Where does this energy come from?

I cannot figure out the answer to part b. I have already calculated part a to be 1.77m/s as velocity of the lighter skater. For part b, I calculated the KE of both skaters and added it together, but that was incorrect. I genuinely don't know how else to do it.