Calculate in newton the weight of 2.5-kg melon. what is it in pounds?

W= weight
w=(9.81N/kg)
w=(9.81N/kg)(2.5kg)
w= 24.525N

1N=0.224808943 pound-force
w= 5.513439327 LB

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.