1. The problem statement, all variables and given/known data Train with mass m=6*105kg moves with a constant speed of v=54km/h.After the engine shut down ,train stops in t=40s .Find the average force train performs before engine shut down? 2. Relevant equations I think its asking for Force ? if yes will this equation below do ? 3. The attempt at a solution F=m/t*(mv2/2) I could be so wrong like GIGANTIC WRONG please braniacs reveal your wisdom on this very rough moment for me !