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Calculate energy lost to a rough surface

  1. Apr 29, 2014 #1
    1. The problem statement, all variables and given/known data
    A block of mass 2kg, moving at velocity 2.68 m/s, slides across a rough 3m surface with a coefficient of kinetic friction of .4. Calculate the energy lost to the 3m rough surface.
    M=2kg
    uK=.4
    V=2.68 m/s
    D=3m


    2. Relevant equations
    1/2mv^2
    uK*Fn*D


    3. The attempt at a solution
    I used the kinetic energy equation of 1/2mv^2 to get 7.18J. Then I did uK*Fn*D to get 24J, where Fn is normal force and Gravity = 10m/s^2. I have no idea where to go from here.
     
    Last edited: Apr 29, 2014
  2. jcsd
  3. Apr 29, 2014 #2

    SammyS

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    What does that 24 J represent ?
     
  4. Apr 29, 2014 #3
    It is supposed to be Jules, but I'm not sure if that's correct.
     
  5. Apr 29, 2014 #4

    SammyS

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    The units are Joules, but what does the 24 Joules represent?
     
  6. Apr 29, 2014 #5
    The energy lost to the rough surface, but how can it lose more energy than what it has?
     
  7. Apr 29, 2014 #6

    SammyS

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    What happens to the block when the energy lost is equal to the initial Kinetic Energy ?
     
  8. Apr 29, 2014 #7
    So the block will stop then, right?
     
  9. Apr 29, 2014 #8

    SammyS

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    Right.
     
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