Two skaters stand facing each other. One skater's mass is 60 kg, and the other's mass is 75 kg. The two skaters push off each other. After the push, the smaller
skater has a velocity of 3.0 m/s. If no other forces are acting on the skaters, what
is the velocity of the larger skater?

v' = 2.4 m/s

Explanation:

Given that,

Mass of one skater, m = 60 kg

Mass of the other's skater, m' = 60 kg

The two skaters push off each other. After the push, the smaller  skater has a velocity of 3.0 m/s.

When there is no external force acting on a system, the momentum remains conserved. It means initial momentum is equal to the final momentum. Let v' is the velocity of the larger skater.

mv = m'v'

So, the velocity of the larger skater is 2.4 m/s.