Two identical solid copper spheres of radius `R` placed in contact with each other. The gravitational attracton between them is proportional to

Options

A. `R^2`
B. `R^(-2)`
C. `R^4`
D. `R^(-4)`

Answer

C

Explanation

`F=(Gmm)/((2R)^2)=(G(4/3piR^3p)^2)/(4R^2)=(4Gpi^2R^4p^2)/9`
`FpropR^4`