- #1

barryj

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## Homework Statement

Isothermal process![/B]

I have a cylinder with base area of 0.01m^2. I have a piston that is 0.1 meters from the bottom giving a volume of 0.001m^3. I have a weight of 1500 Newtons. This gives a pressure of 1.5E5 Pa. Now, I remove 500 Newtons and the piston moves upwards. Volume increases, pressure decreases. What is the work done by the gas on the weight as the piston moves upwards?

## Homework Equations

PV = PV, work = Force X distance, Work = (PV)ln(V2/V1)

## The Attempt at a Solution

See attached solution. Method 1 gives me 50 Joules of work, Method 2 gives 60 Joules of work. Where am I making a mistake? Both methods seem OK to me.