1. The problem statement, all variables and given/known data Kevin has a mass of 84.2 kg and is skating with in-line skates. He sees his 23.2-kg younger brother up ahead standing on the sidewalk, with his back turned. Coming up from behind, he grabs his brother and rolls off at a speed of 1.74m/s. Ignoring friction, find Kevin's speed just before he grabbed his brother. 2. Relevant equations V= d/t ? I have no idea how to solve this eqn! The only eqn i have for perfectly inelastic collision involves center of mass. PLEASE HELP!!