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Assistance in Free Body Diagram Question

  1. Mar 11, 2012 #1

    I'm having a bit of trouble with a Free Body Diagram question and I'm not sure if I'm going about it properly.

    The question asks;

    A 82kg couch is being pushed with a force of 56N at an angle of 40 degrees above the horizontal. If the coefficient of friction between the couch and the floor is 0.051, what is the acceleration of the couch?

    My final answer was it accelerated at 0.02m/s^2.

    I think I am incorrect because I'm not sure if I need to consider the upwards component of the force applied, and I am not sure when calculating the net force, are you supposed to add up the vertical and horizontal and then apply it to the horizontal acceleration? Or are only the net forces on the horizontal important for the forward acceleration?
  2. jcsd
  3. Mar 11, 2012 #2
    I also got a normal force of 803.6N [up]. I wasn't sure if there would be a vertical acceleration involved, so I figured it would be the opposite of the gravitational force.
  4. Mar 11, 2012 #3
    I think I may have figured it out on my own. Please correct me. But the total value of the vertical forces must be 0? So if Fnet= Fg + Fn + Fv, would the normal force be the sum of Fg and Fn?
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