Forces and equilibrium — practice question

A car with mass $860\,\text{kg}$ moves on a level straight road. The engine supplies power $P\,\text{W}$, while the resistive force opposing the motion is $R\,\text{N}$. At one point, the car has speed $4.5\,\text{m s}^{-1}$ and acceleration $4\,\text{m s}^{-2}$. At another point, its speed is $22.5\,\text{m s}^{-1}$ and its acceleration is $0.3\,\text{m s}^{-2}$.