geekhack
geekhack Community => Off Topic => Topic started by: C5Allroad on Mon, 12 January 2015, 17:41:50
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Last year when talking to bio teacher(favorite teacher :p)
We were talking....
Say a small girl, about 4,5' under 100lbs were to go up 4 flights of stairs. And myself, 5,11 190ish I think, would go up, I swim and all. But my logic is that she has tiny legs, and I have big calves, I almost assume she would be working more to go up.
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i don't get it
and i'm even a physics dude
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I dunno lol.
Like a bigger person, vs a smaller person, who would use more energy?
I haven't given much thought on the question, but been thinking about this for a while lol.
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I would assume the little girl would be using more energy. The steps are not built for her size, but they are for yours. It's like you trying to climb a 2 foot wall every time you walk up a stair. You working out means that it would take less strain for you to walk up the stairs. Just like the more you do calf raises, the less it hurts.
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Technically speaking you're both doing the same amount of "work" since you're travelling the same distance.
In practice, the taller person is moving more mass, but has the energy stored to move the mass properly.
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Which -factor- are you trying to determine.. energy-efficiency?
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I’m going to assume this whole thread is a joke troll. But anyway..
and i'm even a physics dude [...]
Technically speaking you're both doing the same amount of "work" since you're travelling the same distance.
What? No. Technically the dude is doing more “work”, proportional to their masses. http://en.wikipedia.org/wiki/Work_(physics) (http://en.wikipedia.org/wiki/Work_(physics))
work = force * distance = 9.8 m/s/s * mass * distance
(assuming gravity at the surface of the earth)
You may want to break back open that high school mechanics textbook, physics dude. :)
I would assume the little girl would be using more energy.
Likewise, the guy is “using more energy”. Calculating the precise amount of energy used is a bit tricky, since it depends on the efficiency of the muscles, circulatory system, etc. We'd need more information about these people and a complicated model of human energy use to calculate it out.
But if all you care about is who uses more energy, it is definitely the man.
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As for who tires out faster, or who could climb more stairs before exhaustion, or who could climb the stairs faster, that’s something you’ll have to verify empirically. At the world-class professional athlete level, a 5'11" 190 lb man is going to have more strength and stamina than a 4'5" 100 lb woman. But I know some short thin women who are amazing athletes and I know some 5'11" 190lbs dudes who can barely walk.
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Starting to make some sense.
I would assume the little girl would be using more energy. The steps are not built for her size, but they are for yours. It's like you trying to climb a 2 foot wall every time you walk up a stair. You working out means that it would take less strain for you to walk up the stairs. Just like the more you do calf raises, the less it hurts.
This was my argument with him.