Gravitational force between two point masses m and M separated by a distance r is F. Now if a point mass 3m is placed next to m, what will be the (a) Force on M dur to m (b) total force on M ?

Explanation

The Gravitational force on m due to M `F = (GMm)/r^2`
a) Since the gravitational force between two point masses is independent of the presence of other masses , So if a point mass 3m is placed next to m, the force doesn.t change . `" " :. F = (GMm)/r^2`
b) Total force on body of mass M is
`F_(1)=(Gm(3m+m))/r^2 = (4GMm)/r^2=4F`