1. Apr 30, 2015

### EzequielSeattle

1. The problem statement, all variables and given/known data
A pocket of air rises 1000 meters. Estimate how much it cools. Use the atmospheric law to determine pressure at 1000 meters.

2. Relevant equations
P = P0 * e-Mgz/RT
PVγ = constant
TVγ-1 = constant

3. The attempt at a solution
Using the atmospheric law, I found the pressure at 1000 meters to be 90202 Pa, or about 0.89 atm. I'm not sure how to use the adiabatic equations. I just assumed V1 was 1 m3, and also assumed that γ=(5/7), as the atmosphere is mainly diatomic. Plugging these in, I got that the gas expands to about 1.09 m3, but when I tried to plug that into my last equation, I got that the gas actually HEATS up, which I know is wrong. What did I do wrong??? Please help!

2. Apr 30, 2015

### Quantum Defect

What is gamma? it should be the ratio of Cp/Cv, correct? Which is larger, Cp or Cv ? Should gamma be greater or less than one?

3. May 2, 2015

### EzequielSeattle

Thank you! I was accidentally using γ=5/7 instead of 7/5. It works now.