How much work is done by the engine?

[zaga04]

Homework Statement

Heat input of an engine is 1330 J/s at 375°C and heat output is 800 J/s.

Each second, how much work is done in the process?

Homework Equations

Q_L/Q_H=1-e

The Attempt at a Solution

Q_L=(1-e)Q_H

Q_H=W/e

W=average of 1330 and 800 which is 1065J

Q_H=1065J/.40 (e was calculated in part A, which I don't need help on).
= 2.6625kJ

Q_L=(1-.40)2.6625kJ
Q_L=1.6kJ/s or 1.6kW

I followed an example in my textbook, the part I am confused on is how to get W, I just took the average of the two that were given.

 

[rock.freak667]

An engine converts heat to work.


So heat is input to the engine, the engine does work and rejects some heat.

If we apply conservation of energy we get.


Heat input=Work done + heat rejected