1. The problem statement, all variables and given/known data A car pf mass 900kg accelerates from rest to a speed of 20 ms^-1 whilst moving 80m along a horizontal road. Find the tractive force (i.e. the driving force) exerted by the engine, assuming that it is constant and that there is a constant resistance to motion of 250N. 2. Relevant equations 3. The attempt at a solution m = 900kg, u=0ms^-1 , v=20ms^-1, s = 80m acceleration = (20-0)/2 = 10ms^-2 force = ma = 900*10 = 9000N workdone = 7.2*10^5J What about the constant resistance to motion of 250?