Question

Two ice skaters stand at rest in the center of an ice rink. When they push off against one another the 45 kg skater acquires a speed of 0.71 m/s. If the speed of the other skater is 0.84 m/s, what is this skater's mass?

Answer 1

Momentum is converved. The momentum initial is zero, the momentum after if
skatermass*.84+45*(-.71)=0