Before we start we should have some idea of the route of our solution. We should observe that force, distance and work have a relation and that mass, velocity and work have a relation. So we should calculate the work done by the brakes stopping the car. W=FD so W = 20030=6000J We know work = change in energy and that the final energy is 0. So we now know that the starting energy of the car KE = 6000J We now look to the kinetic energy equation that states KE = 1/2 * m * v^2 solving for v we have v=sqrt(2KE/m) we now just plug in v = sqrt(26000/1000) = sqrt(12) = 3.46 ms^-1