(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

A heat engine operating between freezing and boling points of water takes 20 cycles to raise a mass of 1000kg through a height of 3m. Calculate the minimum energy per cycle that must be extracted from the hot reservoir in order to achieve this.

2. Relevant equations

η=1-Tc/Th

η=W/Qh

P.E=mgh

3. The attempt at a solution

I assumed that the acceleration woas 9.81m/s^2 so I got 2943J for the Work done and then divided by 20 to get the energy for one cycle to get 147.15J. Plugging into the equation i got Qh= 525.5J which doesn't seem to sound right considering the question is worth 4 marks.Can i assume that the GPE of the mass is the work done or is there more to it? Do I need to include Qc in the work done (WD=Qh-Qc)?

Thanks for any help :)

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# Homework Help: Heat engine- calculating minimum energy per cycle from hot reservoir

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