How much weight would you lose climbing stairs every day (assuming that neither diet nor metabolism changes in response to the extra effort)? (Thanks to Alex Godunov of Old Dominion University for suggesting the question.)
Answer: To answer this, we will assume that climbing stairs expends extra energy and that this extra energy comes entirely from stored fat (i.e., that neither diet nor metabolism changes in response to the extra effort). These are probably horrible assumptions, but they change a psychology or biology problem into a solvable physics problem.
Let’s plan on climbing three flights of stairs daily (more than one [too easy] and fewer than ten [too hard]). A typical flight of stairs is 10 feet or 3 m, so we will climb 10 m of stairs each day. The energy required to do this is
