A 1700 kg automobile is at rest at a traffic signal. At the instant the light turns green, the automobile starts to move with a constant acceleration of3.0 m/s 2. At the same instant a2200 kg truck, travelling at a constant speed of 6.0 m/s, overtakes and passes the automobile.
a) How far is the center of mass of the automobile truck system from the traffic light at t = 3.0s?
b) What is the speed of the center of mass of the automobile-truck system then?