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Homework Help: Help with Statics

  1. Feb 7, 2005 #1
    now on question 8 of my homework, and i am starting to wonder if i;ve been getting these question right. :yuck: It's to do with friction.

    Relativally simple question: When an object is stationary, would the formula to find the resolved friction be: F = (mew, u) R or F (is less-than-or-equal-to) (mew, u) R?!
    sorry bout the notation, have NO idea how to use it!
    thanks in advance
    Padford.
     
  2. jcsd
  3. Feb 7, 2005 #2
    friction

    the normal force (force perpendicular to the plan of motion) is variable based on angle of incline or decline
     
  4. Feb 7, 2005 #3
    thanks, but which formula applies to an object which is stationary, am i being stupid, co i swear our teacher told us one or the other?!
     
  5. Feb 7, 2005 #4
    you have static and kinetic frction the difference is that the constants are different, think about sliding a large object its hard to get it sliding, but you get it sliding its not as hard,
     
  6. Feb 7, 2005 #5

    Doc Al

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    Staff: Mentor

    Static friction is always less than or equal to [itex]\mu N[/itex], where N is the normal force pressing the surfaces together.
     
  7. Feb 7, 2005 #6
    Thank you both very much! Very helpful :rofl:

    -Padford
     
    Last edited: Feb 7, 2005
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