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Homework Help: Centripetal force

  1. Mar 22, 2010 #1
    A 2.4 x 103 N force is necessary to keep a car and driver moving at a speed of 100 km/h through the middle of a highway curve that has a radius of 350 m. What is the mass of the car and driver?

    Im really confused on this question, I was told the formula should be something like

    FC=MV^2 / R

    but how can I find the mass.

    Help!
     
  2. jcsd
  3. Mar 22, 2010 #2

    rock.freak667

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    Yes that formula is correct, can you arrange it so that M alone is on one side of the equation?
     
  4. Mar 22, 2010 #3
    M=fc/r?
     
  5. Mar 22, 2010 #4

    rock.freak667

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    what happened to the v2?
     
  6. Mar 22, 2010 #5
    Im not sure :(

    FC=MV^2 / R

    M=(FC)(V^2)/R?
     
  7. Mar 22, 2010 #6

    rock.freak667

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    From Fc=mv2/r

    if you multiply both sides by r and then divide by sides by v2, what do you get?
     
  8. Mar 22, 2010 #7
    I really have no idea :\
     
  9. Mar 22, 2010 #8

    rock.freak667

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    If ab=c, what is b equal to ?
     
  10. Mar 23, 2010 #9
    not too sure..
     
  11. Mar 23, 2010 #10

    rock.freak667

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    Do you know how rearrange equations to make one variable the subject of the formula?
     
  12. Mar 23, 2010 #11
    Would it be

    m = fc(r)/v^2

    answer 1.1 x 103 kg ?
     
  13. Mar 23, 2010 #12

    rock.freak667

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    That should be correct.
     
  14. Mar 23, 2010 #13
    That you so much! :):)
     
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