Two spheres of mass $m$ and $M$ are situated in air and the gravitational force between them is $F$. The space around the masses is now filled with a liquid of specific gravity $3$. The gravitational force will now be

Two solid spheres each of radius $R$ made of the same material are placed in contact with each other. If the gravitational force acting between them is $F$,then:

$A$ mass $M$ is split into two parts,$m$ and $(M-m)$,which are then separated by a certain distance. What ratio of $\frac{m}{M}$ maximizes the gravitational force between the two parts?

Explain the gravitational force exerted by an extended object.

The gravitational force between a hollow spherical shell (of radius $R$ and uniform density) and a point mass $m$ is $F$. Show the nature of the $F$ versus $r$ graph,where $r$ is the distance of the point mass from the centre of the hollow spherical shell.

Two point objects of mass $2x$ and $3x$ are separated by a distance $r$. Keeping the distance fixed,how much mass should be transferred from $3x$ to $2x$,so that the gravitational force between them becomes maximum?