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posted by  scumscum on 11/3/2007 10:21:08 PM  |  status: Live  

Work Will give high points

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Algebra Based Physics N/A N/A N/A
Question Details:
A man pulls a 10 kg box across a smooth floor with a force of 78 newtons at an angle of 22 degrees and for a distance of 103 meters. How much work, to the nearest joule, does he do?
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(University of Alberta)
posted by Icarus on 11/3/2007 10:28:33 PM  |  status: Live
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scumscum's comment:
"thanks"
Response Details:
When you're dealing with an angle, the work done will be expressed as: W = Fd cosθ, where θ is the angle between the horizontal and the cable being pulled on. So the total work will be:

W = (78 N)(103 m) cos(22) = 7449 J. To keep with significant figures, the answer would be:

W = 7.4 x 103 J or 7.4 kJ.
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(Houghton College)
posted by ktqu on 11/3/2007 10:29:21 PM  |  status: Live
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scumscum's comment:
"thanks"
Response Details:
W = F(Δr)cosθ
 
F=78N
Δr=103m
θ=22
 
W=78N(103m)(cos22) = 7449 J
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