A softball player wishes to determine her mass. She glides frictionlessly along on ice
skates at 2.1 m/s. She is thrown a ball of 0.80 kg mass at 27 m/s. She finds that after the collision is slowed to 1.2 m/s. What is her mass?

Formula: m1 v1 + m1 v1 + m2 v2

A 426 N force acts for 0.037 sec on a 2.5 kg object.