Suppose a child drives a bumper car head on into the side rail, which exerts a force of 3400 n on the car for 0.400 s. (assume the initial velocity is in the positive direction.) (a) what impulse (in kg · m/s) is imparted by this force? (indicate the direction with the sign of your answer.) kg · m/s (b) find the final velocity (in m/s) of the bumper car if its initial velocity was 3.50 m/s and the car plus driver have a mass of 200 kg. you may neglect friction between the car and floor. (indicate the direction with the sign of your answer.) m/s