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Homework Help: Physics work problem - mastering physics

  1. Nov 3, 2008 #1
    Physics work problem -- mastering physics

    1. The problem statement, all variables and given/known data
    163337B.jpg


    Find the work W done by the 15-newton force.

    2. Relevant equations
    W=\vec F\cdot\vec s=\left|\vec F\right|\left|\vec s\right|\cos \theta


    3. The attempt at a solution
    W= 15*cos140*160 = -1838.506
    I don't know why mastering physics was telling me "Not quite. Check through your calculations; you may have made a rounding error or used the wrong number of significant figures."
     
  2. jcsd
  3. Nov 3, 2008 #2
    Re: Physics work problem -- mastering physics

    I don't know if you already figured this out, but the only thing I can think of (and it's not really even related to the error you were getting) is that Mastering Physics requires angle measures to be in radians.
     
  4. Nov 3, 2008 #3
    Re: Physics work problem -- mastering physics

    yes but that shouldn't be affecting the answer though, cos140degree = cos(14/9)pai
    Thanks though
     
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