text: A watt is a Joule/sec. So the engine output is 5 kJ/s. "Your answer differs from the correct answer by 10% to 100%." It would have been helpful to know what you put in to get this response.\n\na) "Expels" ... does that mean wasted energy or useful energy? I'll assume it's useful energy. So 4 times as much energy is wasted - 24000 J.\n\nb) 5 kJ/s * 1 cycle/6 kJ ==> 0.833 cycles/s or 1.2 s/cycle