>>92>>91PE = mgh
50kg person at the top of a hill with a total height of 10m = 50 * 9.81 * 10 = 4900J
It takes 1 kcal to heat 1L of water 1ºC
Energy required to heat 1kg of 10ºC water to 100ºC
90ºC * 1 * 1 = 90 kcal
1 kcal = 4184 Joules
90 kcal = 376,560 Joules
Height of hill required to have this much energy
PE / mg = h
376,560 / (50 * 9.81) = 768 m
376,560 / (100 * 9.81) = 383 m
It feels like I'm doing something very wrong. I intuitively thought you wouldn't need a hill anywhere near that size. Intuition is usually a really bad thing when it comes to physics but I don't really trust my math right now.