- #1

grandpa2390

- 474

- 14

## Homework Statement

I need to find the coefficient of a refrigerator that uses a monatomic gas and only has two steps.

I know the:

initial pressure of the refrigerant

initial temperature

initial volume

and final pressure

Every formula I know requires 4 steps or a knowledge of the outside and inside temperature. This question is unlike anything I have seen to date. The only other problem I have seen like this was for a real refrigerator. it had four steps, and I was given a table for the saturate refrigerant.

## Homework Equations

##COP = \frac{Q_C}{W}##

##COP = \frac{Q_C}{Q_H-Q_C}##

##COP = \frac{T_C}{T_H-T_C}##

## The Attempt at a Solution

Right now, the only thing I can think of is that I could use the equation ##COP = \frac{Q_C}{W}## by finding Q and W of the process the way I did in earlier chapters. And assume that the change in Q is Q_C .

With this attempt, I could take advantage of the formulas that give me these values based on whether or not the gas is monatomic.

Is this the right direction?

edit: I did the problem this way and got a COP of 1...

I assuming that the change in internal energy is 0. the first process is isothermal, and the second process is linear bringing it back to the same initial point. I get that Q=-W so Q/W is 1

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