Energy required to raise 100Kg by 3 M Just a very simple enquiry compared to most of the things I see here.
I'd like to know how much energy is required to raise 100Kg (my weight - sorry - mass) by 3M; the distance from my ground floor up to the 1st floor (2nd floor in USA?).
I do that approximately 20 times a day and am interested to know how much more exercise I shall need to do when I move into a bungalow!!
 A: When you're walking up stairs, you're converting the chemical energy of the sugars in your body into gravitational potential energy.  Gravitational potential energy, fortunately, is very easy to calculate.  The equation is $E=mgh$, where E is the potential energy, m is the mass, g is the acceleration of gravity (9.8m/s^2) and h is the height you raised the mass above its initial starting point.
Plugging these numbers in, we get 2,940 J.
Of course, that's only part of the story. The body is actually only roughly 20% efficient, so you'll actually burn about five times that much, call it 15 kJ.  A Snickers bar has about 900kJ in it, so just watch the snacks and you'll be fine!
Some fun facts on stair climbing:

  
*
  
*Stair climbing is officially classed as a ‘vigorous exercise’ and burns more  calories per minute than jogging.   
  
*Stair climbing requires 8-9 times more energy expenditure than sitting and burns about 7 times more caloriesthan taking a lift.
  
*You burn about 0.17 calories for every step you climb, so you burn roughly a calorie and a half for every 10 upward steps. [1.5 Calories = 6kJ]
  

A: The energy you would require to simply lift a mass by some height, $h$, is given by,
\begin{align*}
E&=m\,\textbf{g}\,h\\
&=100\cdot 9.81\cdot 3\\
&=2943\,\textrm{J}
\end{align*}
Additionally, the force ($F=m\,\textbf{a}$) you would have to apply is about $981\,\textrm{N}$ against the earth’s pull. (I have assumed $\textbf{g}=9.81ms^{-2}$ in solving these, which it may not be exactly where your home is.)
All said and done, though, this is just to lift the mass straight up; in your house, realistically, you would take the stairs etc. and not just move vertically up to the first floor. The exact value that depends on quite a few unknowns, including the height of a stair, the number of stairs etc.
