A 20% efficient real engine is used to speed up a train from rest to 5.00 m/s. It is known that an ideal (Carnot) engine using the same cold and hot reservoirs would accelerate the same train from rest to a speed of 6.50 m/s using the same amount of fuel.
The engines use air at 300 K as a cold reservoir. Find the Temperature of the steam serving as the hot reservoir.
I know the efficiency of Carnot engine is 1- (T_c/T_h) and the thermal efficiency of a heat engine is 1- (Q_c/Q_h). I'm not sure how to set this up.