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Friction problems

  1. Oct 17, 2009 #1
    JOOOOOOOOOOOOOOOOOONWOOOOOOOOOOOOOOOOO NHOOOOOOOOOOOOOOOOOOOOOOOOOOO do your physics hw nooooooob
     
    Last edited: Oct 18, 2009
  2. jcsd
  3. Oct 17, 2009 #2

    rock.freak667

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    the 'x' one is correct.

    For the 'y' one, the resultant force perpendicular to the plane is 0 so -490cos30+N = ? (so what is N?)
     
  4. Oct 17, 2009 #3
    n is
     
    Last edited: Oct 18, 2009
  5. Oct 17, 2009 #4

    rl.bhat

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    Hi zhangsterii, welcome to PF.
    Since crate is moving down a should be...... ?
    In the y direction there is no motion. So in that direction acceleration is zero.
    Now what is the frictional force f?
     
  6. Oct 17, 2009 #5
    [quote=
     
    Last edited: Oct 18, 2009
  7. Oct 18, 2009 #6
    Joooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooooo doooooooooooooooo
    youuuuuuuuuuuuur
    homeeeeeeeeeeeeeei
    worlkkkkkkkkkkkkkk
    boiiiiiiiiiiii
    ^.^
    chico was here
     
    Last edited: Oct 18, 2009
  8. Oct 18, 2009 #7

    rl.bhat

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    For both x and y you have written 50a. How is it that?
     
  9. Oct 18, 2009 #8
    JONNYWOorking on part 2
     
    Last edited: Oct 18, 2009
  10. Oct 18, 2009 #9
    how should the x= and y= equations be set up??
     
    Last edited: Oct 18, 2009
  11. Oct 18, 2009 #10

    rl.bhat

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    When the particle will have uniform velocity in the upward direction?
     
  12. Oct 18, 2009 #11
    umm wat are u talking about?
     
  13. Oct 18, 2009 #12
    weeee
     
    Last edited: Oct 18, 2009
  14. Oct 18, 2009 #13

    rl.bhat

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    I am asking "when the particle moves with uniform velocity?" Refer Newtons first law.
     
  15. Oct 18, 2009 #14
    when there is no accerlation
     
  16. Oct 18, 2009 #15

    rl.bhat

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    Correct.
    When the acceleration is zero on an inclined plane with friction?
     
  17. Oct 18, 2009 #16
    that doesnt make sense...your wording
     
  18. Oct 18, 2009 #17
    when velocity is constant
     
  19. Oct 18, 2009 #18
    fagito
     
    Last edited: Oct 18, 2009
  20. Oct 18, 2009 #19

    rl.bhat

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    Now If you pull the crate in the upward direction, what is the direction of the frictional force?
    What is the net down ward force?
    To move the crate with uniform velocity, how much force you have to apply?
     
    Last edited: Oct 18, 2009
  21. Oct 18, 2009 #20
    hi joonwoo
     
    Last edited: Oct 18, 2009
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