1. The problem statement, all variables and given/known data Compare the amount of metabolic energy used by a typical person running up a flight of stairs to the energy required to light a 100 W light bulb for 1 hour. 2. Relevant equations 3. The attempt at a solution Assumptions: A “typical person” in this situation is being arbitrarily defined as a 578.26 N (130 lb) person and the vertical height of a “flight of stairs” as 4m and the time to climb these stairs as 5 seconds (as per the textbook on pg. 130). The energy needed by this person to go up this flight of stairs: Work = weight * height = 578.26 N * 4m = 2313 J /5 sec. = 462.6 J/s (W) = 27,756 J/hr The energy needed to light a 100W light bulb for 1 hour: If one watt = 1 J/s then 100W =100 J/s x 3600s/1 hour = 360,000 J/hr So, a person utilizes relatively a small amount of energy while going up a flight of stairs compared to running a light bulb for 1 hour?