1. The problem statement, all variables and given/known data: A cylinder is elongated by 2% of its original length. If Poisson's ratio of its material is 0.3. Calculate the percentage variation in volume. 2. Relevant equations V = πr^2l η= 0.3= Δl/l/Δr/r 3. The attempt at a solution I tried using calculus to differentiate V to find change in volume and then divided it by the given volume but could not find and answer as r^2 was left.