1. The problem statement, all variables and given/known data a hollow cylindrical copper pipe is 1.5m long and has an outside diameter of 35cm and an inside diameter of 2.5 cm how much does it weight? 2. Relevant equations ρ = M/V = 8.9E3 w = Mg 3. The attempt at a solution okay, so I know that I can just solve for M because I already have ρ but how do I find volume? do I just do πr^2h but what do I do with the inner and outer diameters?