A car is stopped at a traffic light. It then travels along a straight road so that its distance from the light is given by x(t) = bt^2 - ct^3 where b=2.40 m/s^2 and c = 0.120 m/s^3; (a) calculate the average velocity of the car for the time interval t = 0 to t = 10.0 s (b) calculate the instantaneous velocity of the car at t= 0 to t = 10.0 s.