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Finding the applied force with theta, A, M, and Mu as givens?

  1. Nov 8, 2009 #1
    1. The problem statement, all variables and given/known data
    What must be the applied force (25 degrees above the horizontal) in order to accelerate a block at 1.1 m/s^2, if the mass is 2kg and the coefficient of kinetic friction is .3?

    2. Relevant equations
    F(net y)=Fn + Fav - W
    Ff = μ x Fn
    F(net x)=Fah-Ff

    3. The attempt at a solution
    I've substitued the variables in and gotten these:
    2(1.1) - xsin25 + 2(9.81) = Fn
    Ff = .3Fn
    2(1.1) = xcos25 - Fn

    How do I find Fn?
    Last edited: Nov 8, 2009
  2. jcsd
  3. Nov 8, 2009 #2
    Sorry, I'm not sure how to insert mu as a symbol or do subscripts
  4. Nov 8, 2009 #3
    Just copy and paste this symbol:


    where you need it, and to do subscripts or superscripts, just look at the toolbar at the top of the thread entry and you'll se a bold X with blue 2 subscript/superscript. It's near to big blue eye symbol and the TV icon!
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