# Physics

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Hello I am trying to solve this physics problem related to effusion of gases.

The following data is given and I am asked to calculate the rate of effusion The data given;
depth/thickness (t)
Surface area (A)
diffusion coefficient (D)

Can someone help me out? The only law related is the Graham's Law but it compares two gases.

Thanks

• Physics -

I don't understand the question. Diffusion involves two gases, and you have not said what they are. Effusion is the rate that molecules flow through a hole that is smaller then the mean free path. I don't see how a depth would be involved. For effusion equations, see http://en.wikipedia.org/wiki/Effusion

The characteristic distance than a gas can diffuse into another gas in time t is sqrt(pi*D*t)

D is inversely proportional to pressure.

• Physics -

Its a balloon filled with the nitrogen gas balloon and its about the flow of nitrogen through a hole.

The thickness of the balloon, total surface area and the diffusion coefficient is given.

I am bit confused about the problem as well.