Kinematics of motion in a straight line — practice question

A car with mass $600\,\text{kg}$ is moving on a level straight road, and its engine is delivering power at a rate of $40\,\text{kW}$. The resistive force on the car is steady and has magnitude $800\,\text{N}$. At the point $A$ on the road, the car moves with speed $25\,\text{m s}^{-1}$. The acceleration of the car at point $B$ is one-half of its acceleration at $A$.