1. The problem statement, all variables and given/known data A cubic container with sidelength l has a small hole with cross sectional area a (a<<l). The gas has density ρ and pressure P. Find the initial rate of gas leakage given that the outside pressure is 0. 2. Relevant equations The question mentions the formula p=ρc2/3 so I know I have to use this. 3. The attempt at a solution Assume that 1/3 of the particles are moving in a direction towards the hole. Any molecule in a cylinder of base a and length c will leave the hole in one second so is the leakage rate av/3, and then I can substitute out c with the formula? Is this the correct answer?