1. The problem statement, all variables and given/known data The resultant force acting on a train of mass m starting from rest on a level track is a constant P for speeds less than V . For speeds greater than V the power exerted by the resultant force has a constant value PV . Find the time taken to reach a speed 2V from rest, and the corresponding distance travelled. 2. Relevant equations Force= power * velocity Power= dw/dt 3. The attempt at a solution for some reason, i dont know how to go about doing it.