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Homework Help: Force of gravity between two objects

  1. Mar 21, 2005 #1
    hi i am stuck and dont know what to do next or if i am even on the right path. could someone help me please!!!!!!!!!!!!!! :cry:

    my question is what is the force of gravity between two 100kg cars separated by a distance of 25m on an interstate highway?
    I started out like this:


    fg=Gm1m2+6.67 x 10-11Nm2 x (1000kg) (1000kg)
    r2 kg2 (25m)2



    G=6.67 x 10-11 Nm2
    kg2



    then i dont know what to do or if this is even close






    thanks to anyone with the time to help.
     
  2. jcsd
  3. Mar 21, 2005 #2

    arildno

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    Just plug in the CORRECT values in the formula for F:
    [tex]F=\frac{Gm_{1}m_{2}}{r^{2}},G=6.67*10^{-11}\frac{Nm^{2}}{kg^{2}},r=25m,m_{1}=m_{2}=100kg[/tex]

    Query:Check the value of the mass for each car; are you sure it is 100kg, rather than 1000kg?
     
  4. Mar 21, 2005 #3
    It gives me an extremely small result. Something like 0.0000001 N. It makes sense btw.
     
    Last edited: Mar 21, 2005
  5. Mar 21, 2005 #4

    arildno

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    Would you expect anything else?
     
  6. Mar 21, 2005 #5
    No because gravity weaks considerably with the distance (action at a distance).
     
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