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Two solid sphere of same size of a metal...


Two solid sphere of same size of a metal are placed in contact by touching each other prove that the gravitational force acting between then is directly proportional to the fourth power of their radius.

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The weights of the spheres may be assumed to be concentrated at their centres.
So, `F=(G[(4)/(3)piR^(3)rho])xx([(4)/(3)piR^(3)rho])/((2R)^(2))=(4)/(9)[Gpi^(2)rho^(2))R^(4)thereforeFpropR^(4)`
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