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Homework Help: Basic Friction Problem

  1. Nov 9, 2008 #1
    Hi, Im working on this question its part of a larger question about dynamic viscosity in thermofluids but its the basic mechanics of friction I forget how to do

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

    A block weighing 150N is to be moved at constant velocity 0.8m/s up an inclined surface with a friction coefficient of 0.27. Determine the force F that needs to be applied in the horizontal direction.

    (the elevation of the slope is 20 degrees)

    2. Relevant equations

    F = μN (i think)

    3. The attempt at a solution

    Applying the basic equation to find the horizontal force results in F = μN,
    0.27 X 150 = 40.5N the force required to overcome the friction move the block (Im not sure if the velocity is required for this part but i mentioned it in case it was)
     
  2. jcsd
  3. Nov 10, 2008 #2

    Redbelly98

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    Staff Emeritus
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    Homework Helper

    Because the surface is at an angle, N is not simply equal to the weight, 150 N.

    You can get N by drawing a free body diagram showing all forces on the block, and writing separate equations for the horizontal and vertical force components.
     
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