I'm not really sure how to answer this question about power and energy...
A train on a straight level track is pulled at a constant speed of 23m/s by an engine with an output power of 700kW.
the train then moves on to an inclined section of the railway line where the track rises by 1m for every kilometre of track. Explain why the output power of the engine needs to be increased to maintain the same speed of 23m/s.