Calculating Work done

  • Thread starter fiziks09
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  • #1
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Homework Statement



A box of mass 6.0kg is accelerated from rest by a force across the floor at a rate of 2.0m/s for 7.0s. Find the net work done on the box.


Homework Equations


Work done = Force x distance


The Attempt at a Solution


F = ma
F = 6 x 2 = 12N
i solved for final velocity i.e

V = u + at
= 0 + 2(7)
V = 14m/s.

i solved for distance

using v^2 = u^2 + 2as i.e
169 = 0 + 4s
s = 169/4
s = 49
we know that W = fd; thus
W = 12 x 49
W = 588J.

Please i just wanna know if my solution is correct. The answer in my text book is 590J. I'm assuming it was rounded up but i just want to be sure. Thanks for any help.
 

Answers and Replies

  • #2
kuruman
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It is correct, as long as the box is accelerated from rest by a force across the floor at a rate of 2.0m/s2, not 2.0 m/s as you have posted.
 
  • #3
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yeah.. it is m/s^2 .. my mistake
thanks
 
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