This is a question from the MCAT, test 3R, and I am stumped as to why the answer is what it is. "A mass is lifted from the ground to an altitude h1, requiring work W1. The work to lift an identical mass to height h2 is W2. If h2 is twice h1, what is the ratio of W2 to W1? Assume force due to gravity does not change betweenh1 and h2." I thought this was a simple W = mgh problem, resulting in an answer of 2:1.. but the answer key states its root(2):1! Any idea why?