How long will it take them to glide to the edge of the rink?

At the center of a 50 m diameter circular ice rink, if a 77 kg skater traveling at 2.3 m/s and then collides with a 63 kg skates traveling at 3.7 m/s. This is how long it will take them to glide to the edge of the rink:

Speed after the collision = √{[77 (2.3) 77^2] + [63 (3.7) ^2]} / (77+63) = 2.09 m/s

For them to be able to get to the edge which is 50 m away it will take them 23.9 seconds.