Two objects,each of mass $1\,kg$,are placed at a distance of $10\,cm$ from each other. Calculate the gravitational force between them.

Two spheres of radius $R$ are placed in contact as shown in the figure. If the mass density of each sphere is $\rho$,find the gravitational force between them.

The mass of the moon is $1\%$ of the mass of the earth. The ratio of the gravitational pull of the earth on the moon and that of the moon on the earth will be

Two spheres of masses $m$ 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

Let $G, W, E$ and $S$ be the relative strengths of gravitational, weak-nuclear, electromagnetic, and strong-nuclear forces, respectively. Which of the following statements is correct?

Two metallic spheres each of mass $M$ are suspended by two strings each of length $L$. The distance between the upper ends of the strings is $L$. The angle which the strings will make with the vertical due to the mutual attraction of the spheres is