A new-car owner wants to show a friend how fast her sports car is. The friend gets in his car and drives down a straight, level highway at a constant speed of 60 km/h to a point where the sports car is waiting. As the friend's car just passes, the sports car accelerated at a rate of 2.0 m/s^2. (a) How long does it take for the sports car to catch up to the friend's car? (b) How far down the road does the sports car catch up to the friend's car? (c) How fast is the sports car going at this time?

Question

A new-car owner wants to show a friend how fast her sports car is.  The friend gets in his car and drives down a straight, level highway at a constant speed of 60 km/h to a point where the sports car is waiting.  As the friend's car just passes, the sports car accelerated at a rate of 2.0 m/s^2.  (a) How long does it take for the sports car to catch up to the friend's car?  (b) How far down the road does the sports car catch up to the friend's car?  (c) How fast is the sports car going at this time?

anonymous · Answer

s1 = v1 t
s2 = (1/2) a t^2 

set s1 = s2 and solve for t
that will also give you s2
v2 = a2 t