A motorist traveling with a constant speed of 15m/s passes a school-crossing
corner, where the speed limit is 10m/s. Just as the motorist passes, a police
officer on a motorcycle stopped at the corner stars off in pursuit with constant
acceleration of 3m/s2
. (a) How much time elapses before the officer catches up
with the motorist? (b) What is the officer’s speed at that point?
(a) v t = 1/2 a t^2 ... 15 t = 1.5 t^2 ... t^2 - 10 t = 0 ... t = 10
(b) v = a t ... v = 3 m/s^2 * 10 s ... v = 30 m/s