Calculate the acceleration of 25kg object that is moved with a force of 300n

F=ma -> a=F/m 
a = 300N/25kg = 12 m/s^2 

(note 1N = 1 kg*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.