593
xkcd #2935: Ocean Loop
(imgs.xkcd.com)
A community for a webcomic of romance, sarcasm, math, and language.
I think so. At the apex of the loop gravity balances centrifugal force, Fg = Fc, when going the minimal speed necessary to get through the loop. Fg = m g, Fc = m v^2 / r. So mass m drops out of the equation.