An inventor claims to have developed an engine that during a certain time interval takes in 110 MJ of heat at 415 K, rejects 50 MJ of heat at 212 K while manages to do 16.7 kW of work. Do you agree with the inventor's claim ?

An inventor claims to have developed an engine that during a certain t

1.	An inventor claims to have developed an engine that during a certain time interval takes in 110 MJ of heat at 415 K, rejects 50 MJ of heat at 212 K while manages to do 16.7 kW of work. Do you agree with the inventor's claim ?
Answer» Solution :The CLAIMED EFFICIENCY `eta_c= W/(Q_H) = ( 16.7k Wh )/( 110 mJ)` butas ` 1kWh = 10 ^3 xx ( j xx S ) xx ( 60 xx 60 s)= 3.6MJ` `Soeta_C= ( 16.7xx 3.6)/( 110 )= 0.55= 55 %` whilemaximumpossibletheoeticalefficiency ` eta_("max")=1- (T_L )/( T_H)= (T_H -T_L)/(T_H)= ( 415 -212 )/( 415 ) = 0.49= 49 % ` Eqns. (1) and (2) it is CLEAR that claimed efficiency is greater than maximum possible theoretical efficiency, so inventor.s claim does not appear to be correct.