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Friction torque

  1. Oct 18, 2015 #1
    can kinetic friction cause a torque? (can it result in rotation)
    Or is it that only static friction can cause a torque?

    Can static friction do work on a rolling object?
    I think it can? because the rotational kinetic energy is increasing? is this right???
  2. jcsd
  3. Oct 18, 2015 #2


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    First question response: Ask your self "what is the result of friction?" and "what does it take to create torque?" and you should see the answer to your question.

    Second question response: The answer to the first question should let you know if the second statement is true.
  4. Oct 18, 2015 #3


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    Science Advisor
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    Yes it can: if the line of action of the friction force doesn't go through the center of mass, then that force represents a torque.
    Yes it can: if the object is sliding and rolling you can have what you describe. So in exercises the term "rolling without sliding" may appear to exclude that.

    [edit]JBA was faster !
  5. Oct 18, 2015 #4


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    Your are right in both of your answers except wrong in your statement about "static" friction applying to sliding while rolling, because that is kinetic friction; which, can also create torque and rotation while sliding.
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