Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

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


    User Avatar
    Staff Emeritus
    Science Advisor
    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.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook