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Eraser sliding down slope - Friction

  1. Jun 1, 2005 #1
    An eraser slides down a slope of height 1m that makes an angle of 35 degrees with the ground. It takes the eraser 1,8s to do this. Find the coefficient of friction.

    I have no clue how to do this. I've not been able to solve any of the equations I've tried, because there is always the mass of the eraser which I don't know.

    - Kamataat
  2. jcsd
  3. Jun 1, 2005 #2


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    Start by identifying the forces in the problem. What are they? What is their magnitude? What about their direction?
  4. Jun 1, 2005 #3


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    Just call the eraser's mass 'm', it should take care of itself.
  5. Jun 3, 2005 #4
    What am I supposed to do with the given time?

    The forces are gravity, friction and the normal force?

    - Kamataat
  6. Jun 3, 2005 #5


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    The forces are constant, and do not change throught time, so the acceleration will be constant, you can use the uniform acceleration equations with the time. Notice you can calulate the distance covered.
  7. Jun 4, 2005 #6
    figured it out. thanks!!!!!!

    - Kamataat
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