# Question on waves

1. Sep 4, 2009

### WiFO215

When you have a wave in sound inside a piston of length L, A.P. French says that the fundamenal frequency $$\nu$$ of an oscillation is given by

$$\nu$$ = 1/4L $$\sqrt{(\gamma$$ p / $$\rho)}$$

Where p is the pressure, $$\gamma$$ is the factor that accounts for adiabatic compression of the gas, and $$\rho$$ is it's density.

My question is this : doesn't the pressure p vary as you compress the gas? How can you assume it to be constant?

2. Sep 5, 2009

### WiFO215

Hold up. I think I got it. That's not ANY pressure that you plug in to that formula, it's the pressure when the gas is at equilibrium.

Share this great discussion with others via Reddit, Google+, Twitter, or Facebook