1. The problem statement, all variables and given/known data A particle of mass 5m moving with speed v explodes and splits into two pieces with masses of 2m and 3m. The lighter piece continues to move in the original direction with speed 5v relative to the heavier piece. What is the actual speed of the lighter piece? 2. Relevant equations Momentum = Mass x Velocity 3. The attempt at a solution The answer is 4v, as stated in the answer sheet, but I've no idea how to get it. Appreciate any help here, thanks!