Question

Compare the work that a 22-kW car engine does in 60 seconds if its efficiency changes from 100% to 75%.

Answer 1

1 kW = 1 kJ/s
Work done
= 22 kW * 60 s
= 22*60 kJ
= 1320 kJ

If the efficiency changes to 75% from 100%, the work done is reduced in the same ratio.

Answer 2

thanks mate...