Where does this energy come from?

[cali_sk8er205]

Two figure skaters, one weighing 675 N and the other 750 N, push off against each other on very smooth ice.

1. If the heavier skater travels at 1.20 m/s, how fast will the lighter one travel?
2. How much kinetic energy is "created" during the skaters' maneuver?
3. Where does this energy come from?

is this right...

1. Conservation of momentum
Momentum of heavier skater = 1.2*750 = 900kgm/s
Velocity of lighter skater = 900/675 = 1.33m/s

2. KE of heavier = 1/2*m*v^2 = 0.5*750*1.2^2 = 540J
KE of lighter = 0.5 * 675 * 1.3^2 = 600J
Total KE = 1140J

3. It is created from the energy the two skaters use to push away from each other

 

[naresh]

The skaters don't weigh 675 and 750 kg (now that would be scary!)