posted by help .
At the instant the traffic light turns green, an automobile starts with a constant acceleration a of 2.3 m/s2. At the same instant a truck, traveling with a constant speed of 9.4 m/s, overtakes and passes the automobile.
(a) How far beyond the traffic signal will the automobile overtake the truck?
(b) How fast will the car be traveling at that instant?
at some time t, the same time for both cars, they have went the same distance d.
You have two equations
Car: d=1/2 a t^2
set the equal, solve for t, thensolve for d.