Chasing a Truck At the instant the traffic light turns green

Chasing a Truck At the instant the traffic light turns green, an automobile starts with a constant acceleration a of 1.9 m/s^2. At the same instant a truck, traveling with a constant speed of 9.4 m/s, overtakes and passes the automobile. How far beyond the traffic signal will the automobile overtake the truck? How fast will the car be traveling at that instant?

Solution

a) v t = 1/2 a t²

t = 2 v / a = (2 * 9.4) / 1.9 = 9.89 s

D = v t = 9.4 * 9.89

= 92.966 m

b) V_c = a * t = 1.9 * 9.89

= 18.79 m/s