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Info hunt \ maximum frictional force

  1. Mar 26, 2012 #1
    First of all I would like to clearify that I am in a programme that gives physics questions with littile previous learning and relies on individual determenation and efforts to deliver answers " Self learning " , " Info Hunt "
    In the time most of you were learning science
    I was busy learning English ,
    I never studied physics in my life in Arabic nor in English
    So please have patient and help me through my beginning
    Hopefully that is answering a lot of assumptions
    " Oh this guy is playing " " Get serious " ...etc

    Question :
    A body with mass 25 kg lying on a level floor has a steadily increasing horizontal force applied to it . If mu = 0.4
    Calculate the maximum frictional force applied ?

    Now I'm not asking for a quick answer like past attempts ,
    I'm asking you to guide\help me understand\solve it my self
    As I know no method or a clue of what to do ...
     
  2. jcsd
  3. Mar 26, 2012 #2

    SammyS

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    Staff Emeritus
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    What do you know about frictional force ?
     
  4. Mar 26, 2012 #3

    gneill

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    Staff: Mentor

    Look up "static friction".
     
  5. Mar 26, 2012 #4
    I know that friction is the force that is acting against motion
    What I understood is, the term frictional force means basically the amount of resistance that the friction can demonstrate against a body's motion acted upon by an opposite force
    to prevent it or slow it down .
     
  6. Mar 26, 2012 #5
    My approch to solve now is :
    to get the max friction I'll use this equation :
    f = mu F
    f : max friction
    mu : coefficient of friction
    F : Normal force
    ,
    What I have in the Question
    Is the mass 25kg and the mu 0.4 , and as it is laying on a level floor
    I got g 9.81 m\s
    ,
    So to apply the first equation I would need to find the normal force by this one:
    N= m g
    ....
    Gents am I going through the correct way ?
     
  7. Mar 26, 2012 #6

    gneill

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    So far so good. You've got the normal force, so what's the maximal frictional force?
     
  8. Mar 26, 2012 #7
    f = mu F
    f = 0.4 x 245.25
    f = 98.1 N
    Answer is
    Maximum frictional force is 98.1 N
    ?
     
  9. Mar 26, 2012 #8

    gneill

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    Looks good :smile:
     
  10. Mar 27, 2012 #9
    Many thanks
     
    Last edited: Mar 27, 2012
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