Question

A steam engine delivers `5.4xx10^(8)J` of work per minute and absorbs `3.6xx10^(9)J` of heat per minute from its boiler. What is the efficiency of the engine? How much heat is wasted per minute?

Answer 1

Output, i.e., useful work done per min.`=5.4xx10^(8)J`
Input, i.e, heat absorbed per min. `=3.6xx10^(9)J`
Efficiency `=(output)/(i nput)= (5.4xx10^(8))/(3.6xx10^(9))= 0.15= 0.15xx100%= 15%`
Heat energy wasted// minute = Heat absorbed// minute- useful work done// minute
`= 3.6xx10^(9)-5.5xx10^(8)= 10^(9)(3.6-0.54)= 3.06xx10^(9)J`