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Homework Help: The Work Done in Pulling a Supertanker

  1. Jul 23, 2009 #1
    1. The problem statement, all variables and given/known data

    Two tugboats pull a disabled supertanker. Each tug exerts a constant force of 1.90×10^6 N , one at an angle 13.0 degrees west of north, and the other at an angle 13.0 degrees east of north, as they pull the tanker a distance 0.840 km toward the north.

    2. Relevant equations

    3. The attempt at a solution

    2 * (1.90×10^6 N) * cos(13) * 0.84 * 10^3 = 2.9 * 10 ^9

    can anyone tell me where I did a mistake?

    Thanks a lot before hand
  2. jcsd
  3. Jul 23, 2009 #2


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    Homework Helper

    It does not look like you made a mistake.
  4. Jul 23, 2009 #3


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    Solution to what?
  5. Jul 23, 2009 #4
    It is showed that I made a mistake :(
    Rounding error..
    It is 3.11 not 2.9 :(

    Thanks a lot though! :)
    Last edited: Jul 23, 2009
  6. Jul 23, 2009 #5
    The correct answer is 3.11E+9. Make sure you use 13 DEGREES and not 13 RADIANS. If you entered into a *dumb* calculator, it usually assumes radians. Try writing

    2*1.9E6*cos(13*pi/180)*0.84E3 into google, and it gives you the right answer.
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