A 150 x 103-kg car starts from rest and accelerates

Question

Solve the all parts of following question:

Question: A 1.50 x 10³-kg car starts from rest and accelerates uniformly to 19.5 m/s in 12.6 s. Assume that air resistance remains constant at 400 N during this time.

Part A: Find the average power developed by the engine.

Part B: Find the instantaneous power output of the engine at t = 12.6 s, just before the car stops accelerating.

I want help to find the average power developed by the engine.