work vs walking ?

The difficulty with your question is finding how much energy it takes to walk a given distance at a given speed. You could pull numbers out of the air: like walking 10 hrs/day at 2.5 MPH on a 2000Cal diet.

But then you would also need to know the amount of energy it takes to climb 10 ft. I can say with certanty that your energy cost is way higher than the potential energy you gained in the climb. You are not a 100% efficient machine, after all.

So in the end, it's down to experimental biologists using respirometers for O2 consumptiom of the carbohydrates in your food/fuel for establishing your energy costs.

Brian Whatcott Altus OK

I just noticed that I made a typo, it's 2000 ft-lbs of work. I'm not talking about power because that adds another factor, time. The same amount of work is done if I climb the stairs in 10 seconds or 100 seconds. The work equation is very hard to use for walking on level ground and that was the reason for my question. Hank in Tulsa

Dear Henry Kolesnik:

*Reversible* work, yes.

If we spend all day sitting and resting, why do we still have to eat? It takes energy to live, even to walk. But it is (mostly) not reversible energy. You are looking at the wrong equations.

Brian pointed you in the right direction, you need to look a published values for "calories burned" doing different things, and do units conversion (1 food calorie = 1,000 heat calories).

David A. Smith

Try a Google search on 'energy expended in walking'

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That would certainly be the case if this were a school physics problem. But people are not machines - and it takes energy simply to stand still and erect.

Brian Whatcott Altus OK

Good thought! This URL....

...claims that walking two miles (briskly i.e. for 30 min) is equivalent to stair walking for 15 minutes, and either consume about 150Cal more than if you hadn't done either.

Brian Whatcott Altus OK

Remember that the Calories (capital "C") that are used by the diet and exercise people are really 1000 thermodynamic calories (lower case "c"); in other words, a kilocalorie.

Olin Perry Norton

That's why people invented stair examples for use in engineering though. Since for a long time people were dumb enough to use horses and sand.