Fun fact, the (rough) conversion efficiency of calories to mechanical joules in the human body (separate from the mechanical to electrical you're referring to) is about 25% --- but this is about the same factor as going from calories to joules! So, for a human to put out 13.5 kJ of energy would require about 13.5 food calories (kilocalories).
Fun fact, the (rough) conversion efficiency of calories to mechanical joules in the human body (separate from the mechanical to electrical you're referring to) is about 25% --- but this is about the same factor as going from calories to joules! So, for a human to put out 13.5 kJ of energy would require about 13.5 food calories (kilocalories).