Energy, work and power — practice question

A cyclist together with her bicycle has a combined mass of $84\,\text{kg}$. She delivers power at a steady rate of $P\,\text{W}$ while travelling along a straight road that is sloping at an angle $\theta$ to the horizontal, where $\sin\theta = 0.1$. When she is going uphill, the cyclist’s acceleration is $1.25\,\text{m s}^{-2}$ at the moment when her speed is $3\,\text{m s}^{-1}$. When she is going downhill, the cyclist’s acceleration is $1.25\,\text{m s}^{-2}$ at the moment when her speed is $10\,\text{m s}^{-1}$. The resistive force opposing the cyclist’s motion, whether she is travelling uphill or downhill, is $R\,\text{N}$.