1. The problem statement, all variables and given/known data Hello- I'm having trouble understanding a problem: Consider a sealed 1D pipe of length L. At t=0, v=0 everywhere and the pressure is given by: P=P_0 +δP and δP = (p-bar)x/L P_0 and (p-bar) are both constants. and I'm supposed to find density (ϱ) as a function of x and t. I don't understand why I'm given the pressure, and how to find δϱ. 2. Relevant equations 3. The attempt at a solution Using the boundary conditions, I have an expression for the velocity with sin terms. But I don't know how to use that to find the density as a function of (x,t).