http://www.math.rutgers.edu/~greenfi...dfstuff/w2.pdf

Problem 2:

Basically I know how to calculate the work for the cylinder. Since they have the same volume, we know the volume of the cones, but since they are the same depth underground, then how is the answer going to be different for any of these three. I know the work is the integral of the force, and the force is basically found by taking the volume * density * g...so why are they going to be different and how can I know?