Newton's laws of motion — practice question

A railway engine with mass $120000\text{ kg}$ is hauling a coach with mass $60000\text{ kg}$ along a straight track that rises at an angle $\alpha$ to the horizontal, where $\sin \alpha = 0.02$. The engine and coach are linked by a light rigid coupling, parallel to the track. The engine supplies a driving force of $125000\text{ N}$, and the constant resistances to motion are $22000\text{ N}$ on the engine and $13000\text{ N}$ on the coach.