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## Homework Statement

Derive an expression for the effiency of the cycle (of a Stirling Engine) working between two heat baths at temperatures T1 and T2 with volumes in the ratio V2/V1. Assume the working substance is a monatomic ideal gas.

## Homework Equations

Work done=heat absorbed from going from V1 to V2 at constant temperature and is given by:

RT ln(V2/V1)

Heat absorbed in going from T1 to T2 is:

(3/2)R(T2-T1)

efficiency=1-Q2/Q1 where Q2 is the heat lost per cycle and Q1 is the heat gained per cycle.

## The Attempt at a Solution

I have an expression but I have no idea if it was correct. I tried to google what the correct efficiency should be but I couldn't find it. My expression is:

[tex]\eta = \frac{(T_2-T_1) (ln(V_2/V_1)+3)}{T_2 ln(V_2/V_1) +1.5(T_2-T_1)}[/tex]

I don't think it's right, it looks a bit messy. If someone could tell me if it's correct or not that would be a great help. It would be an even greater help if someone could tell me where I have gone wrong or give me the correct expression so I can work out how to derive it.

Thanks.