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Homework Help: Quick help with Power problem

  1. Oct 30, 2007 #1
    Quick help with Power problem!!

    1. The problem statement, all variables and given/known data
    What is the minimum horse power a motor must have to be able to drag a 310 kg box along a level floor at a speed of 1.2 m/s if the coefficient of friction is .45

    2. Relevant equations
    fg=mg - - - > (c of f) (fn)= Ff
    P = Fv

    3. The attempt at a solution

    I found Ff to be 1367 N but I am unsure of how to find the force with the motor is putting on the box.. I know that the box is not acclerating. so i tried going -1367 +F= 0 and the putting that in the power formula but that did not give me the correct answer
  2. jcsd
  3. Oct 30, 2007 #2


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    Homework Helper

    Are you remembering to convert it from watts to horsepower?
  4. Oct 30, 2007 #3
    ok i got it thanks.. i was thinking that there was another force in addition to the 1367. but i figured it out.
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