Suppose a child drives a bumper car head on into the side rail, which exerts a force of 4000 n on the car for 0.200 s. (a) what impulse is imparted by this force? (b) find the final velocity of the bumper car if its initial velocity was 2.80 m/s and the car plus driver have a mass of 200 kg. you may neglect friction between the car and floor.