Brutus, a champion weightlifter, raises 221 kg of weights a distance of 2.45 m.
How much work is done by Brutus lifting the weights?
I can't figure it out, because I thought Work= Force x Distance.
But the force isn't given here. But doesn't F= mass x acceleration? but there's no acceleration here?
And I know the answer isn't 0.
*confused*
3:26 am on Nov. 20, 2008
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Rollo Tomasi
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acceleration is 9.8 m/s^-2
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Rollo Tomasi
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you know...gravity?
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( Anonymous )
Quote: from Rollo Tomasi at 3:27 am on Nov. 20, 2008
acceleration is 9.8 m/s^-2
Are you saying the acceleration is negative?
I see a -2 there.
3:28 am on Nov. 20, 2008
Rollo Tomasi
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...god damn son, you need a lot more help than i can give you
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3:29 am on Nov. 20, 2008 | Joined: Oct. 2006 | Days Active: 423 Join to learn more about Rollo TomasiAustralia | MetrosexualMale | Posts: 15,305 | Points: 14,072
Quote: from Rollo Tomasi at 3:29 am on Nov. 20, 2008
...god damn son, you need a lot more help than i can give you
Leave.
3:29 am on Nov. 20, 2008
Rollo Tomasi
Enlightened One Patron
i will, but i take comfort knowing that only one of us here is stupid.
and because i know you won't be able to figure out which one of us it is, i am also here to tell you that it is you who is stupid.
hth.
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Killtyronedead
El Cowboy Rojo Patron
Quote: from Anonymous at 6:28 am on Nov. 20, 2008
Quote: from Rollo Tomasi at 3:27 am on Nov. 20, 2008
Gravity is acceleration in the direction opposite the one of motion, namely down when the weight is moving up.
W = F x d F = m x a
Therefore:
W = m x a x d
W = 221kg x 9.8m/s^2 x 2.45m
Also, Rollo Tomasi's notation is correct.
W = 221kg x 9.8ms^-2 x 2.45m
This results in:
W = 5306.21 J W = 5.3 kJ
There you go. That was immensely simple. I think you need a tutor. Badly.
FP
Post edited at 3:46 am on Nov. 20, 2008 by FurryPanther
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Quote: from roflfuckyou at 4:45 am on Nov. 20, 2008
i get 5306.21J as the work
don't know if it's right though.
That's right. 5.3kJ with significant figures.
FP
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roflfuckyou
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yeah i just did sum of the forces = m x a a = gravity m = 221kg
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acceleration is 9.8 m/s^-2
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