A monorail starts from rest and accelerates at a rate of 2.2 m/s^2 for 10 s. Then it turns at a constant speed for 74 s then slows down at a rate of 1.5 m/s^2

If the heat engine is a perfect carnot cycle engine, thenefficiency = (t2-t1)/t2   where t1=temperature of cold reservoir ( ° k) = 135            t2=temperature of hot reservoir ( ° k)   = 325thereforeefficiency = (t2-t1)/t2 = (325-135)/325 = 0.5846 = 58%  note: this is the theoretical maximum efficiency of a perfect heat engine.   real-life engines do not achieve this value.