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

The mass of the Moon is approximately $10\%$ of the mass of the Earth. What will be the gravitational force exerted by the Moon on the Earth compared to the gravitational force exerted by the Earth on the Moon?

Two bodies of masses $8 \,kg$ are placed at the vertices $A$ and $B$ of an equilateral triangle $ABC$. $A$ third body of mass $2 \,kg$ is placed at the centroid $G$ of the triangle. If $AG=BG=CG=1 \,m$, where should a fourth body of mass $4 \,kg$ be placed, so that the resultant force on the $2 \,kg$ body is zero?

We can shield a charge from electric fields by putting it inside a hollow conductor. Can we shield a body from the gravitational influence of nearby matter by putting it inside a hollow sphere or by some other means?

From a sphere of mass $M$ and radius $R$,a smaller sphere of radius $\frac{R}{2}$ is carved out. For the configuration shown in the figure where the distance between the center of the original sphere and the center of the removed sphere is $3R$,the gravitational force between the two spheres is:

$A$ suitable unit for gravitational constant is