Suppose you throw caution to the wind and eat too much ice cream and cake on the order of 500 Calories. To compensate, you want to do equivalent amount of work climbing stairs or a mountain. How much total height must you climb?(Take you mass to be about `60\ kg`.) Given: `E = 500` Calories`=(500\ kcal)(4.186 times 10^3\ J//kcal) = 2.1 times 10^6\ J` `m = 60\ kg` Equation: `W = ∆PE = mgh` Solution: `W = mgh = E` `=>` `h = E/(mg)` `h = (2.1 times 10^6\ J)/((60\ kg)(9.80\ m/s^2))` `h = 3600\ m` Note the human body does not transform energy with 100% efficiency, it is more like 20% efficient. `(3600\ m)times20% = 720\ m`