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Homework Help: Kinetic Friction H E L P ! ! !

  1. Oct 6, 2004 #1
    When mass M is at the position shown, it is sliding down the inclined part of a slide at a speed of 1.89 m/s. The mass stops a distance S2 = 1.85 m along the level part of the slide. The distance S1 = 1.25 m and the angle theta = 37.7 degrees. Calculate the coefficient of kinetic friction for the mass on the surface.

    Well i kinda found a formula for this by changing the conservatiion of energy(K_f+U_f=K_i+U_i+W_nc).

    The formula is mu_k=(-1/2*(V_i^2)-1/2*(g*h))/(g*S_total),

    But I still dont get the right answer am I doing something wrong?
     
  2. jcsd
  3. Oct 6, 2004 #2

    arildno

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    Think again:
    You haven't used the information that you are on an INCLINED plane!!
     
  4. Oct 6, 2004 #3
    I used the incline plane to figure out h=Ssin37.7=0.26
     
  5. Oct 6, 2004 #4

    arildno

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    It's still wrong, you've used a frictional force: [tex]\mu{mg}[/tex]
    This is incorrect.
    In addition, your signs are messed up
     
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