Problem: A 30-cm-tall, 4.0-cm-diameter plastic tube has a sealed bottom. 250 g of lead pellets are poured into the bottom of the tube, whose mass is 30 g, then the tube is lowered into a liquid. The tube floats with 8.0cm extending above the surface.
Part A: What is the density of the liquid?
Please explain the equations and steps are used to get the answer. Thanks!