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Magnetic force vs gravity

  1. Aug 10, 2008 #1
    i have two magnets and i want to repel one magnet against gravitational force upwards..so how powerful the magnet should be?i can calculate the gravitational force using newton's law f=gm1m2/r2 where m1 is mass of earth and m2 is mass of one magnet...so the magnetic force should be greater than this force ....help me...
  2. jcsd
  3. Aug 10, 2008 #2
    You require the force on the magnet to be equal to the force of gravity, as you said.

    [tex] F = I \Delta l B sin \theta = \frac{Gm_{1}m_{2}}{r^{2}} [/tex]
  4. Aug 10, 2008 #3


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    Hi spidey! :smile:

    Technically, it's Gm1m2/r2,

    but we can write Gm1/r2 = g, the usual gravitational constant at the Earth's surface,

    so f = Gm1m2/r2 = m2g. :smile:
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