A 1.50 ✕ 103-kg car starts from rest and accelerates uniformly to 19.3 m/s in 11.7 s. Assume that air resistance remains constant at 400 N during this time.

(a) Find the average power developed by the engine.
W

(b) Find the instantaneous power output of the engine at t = 11.7 s, just before the car stops accelerating.