A 735 N person walks up three flights of stairs, covering a total vertical distance of 10.0 m. If, as is typical, only 20.0% of the caloric (food) energy is converted to work by the muscles, how many joules and food calories of energy did the person use? (One food calorie 4186 J.)

Question

A 735 N person walks up three flights of stairs, covering a total vertical distance of 10.0 m. If, as is typical, only 20.0%  of the caloric (food) energy is converted to work by the muscles, how many joules and food calories of energy did the person use? (One food calorie 4186 J.)

drwls · Answer

Five times the energy needed to climb the stairs. That would be 5 x 735 x 10 Joules. Convert that to food calories using the conversion factor provided.