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Homework Help: Friction, inclined slope

  1. Aug 13, 2005 #1
    hi peeps, can u guys help me with this question:

    A wheel weighing 40kg is rolling down a hill, inclined at 30 degrees. After reaching a speed of 5m/s, the wheel falls over on its side and begins sliding down the hill.
    1. if the coefficient of friction for the sliding wheel is 1.00, independent of the wheel's velocity, how long will it take the wheel to come to a complete halt?
    2. if the coefficient of friction is instead 0.500, will the wheel still stop? why or why not?

    im having trouble with the thing about the wheel becoming sliding after reaching 5m/s. i would really appreciate some help.

  2. jcsd
  3. Aug 13, 2005 #2
    What exactly is the problem you're having? An object sliding down an inclined surface at 5 m/s encounters a frictional force. When the coefficient of friction is 1, what do you know about the net force on the wheel?
  4. Aug 13, 2005 #3
    like you said, the wheel falls over after 5 m/s
    like, if i were standing around and fell over.
    on my face

    a wheel on its side is just a round thing with rubber on it's sides; it's going to slide around, not roll, correcto?
  5. Sep 19, 2010 #4
    I have the same problem. What I did was get the parallel force (mg sin theta) and subtract that with the friction force (coefficient*m*g) to get the net force. Then I set this equal to ma to get the acceleration. But I'm wondering if the initial velocity has any play in calculating the acceleration. When I imagine it visually it seems the initial velocity would have increased the acceleration. But in my formulas, v0 didn't appear at all, unless it was somehow canceled out?
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