Three spherical balls of masses $1 \mathrm{Kg}, 2 \mathrm{Kg} \mathrm{and} 3 \mathrm{Kg}$ are placed at the corners of an equilateral triangle of side $1 \mathrm{m}$. Find the magnitude of gravitational force exerted by the $2 \mathrm{Kg}$and $3 \mathrm{Kg}$  masses on the $1 \mathrm{Kg}$ mass. ($G=6.67\times {10}^{-11} {\mathrm{Nm}}^2/{\mathrm{kg}}^2$)

A satellite orbits the earth at a height equal to the radius of the earth. Find its orbital speed in $\mathrm{km}/\mathrm{s}$. ($G=6.67\times {10}^{-11} {\mathrm{Nm}}^2{\mathrm{kg}}^{-2},$mass of earth $M=6\times {10}^{24 }\mathrm{kg}$, radius of Earth $R=6400 \mathrm{km}$) (Answer up-to three places of decimal)

A satellite orbits the earth at a height equal to the radius of the earth. Find its period of revolution in hours(write the value to the nearest integer).

($G=6.67\times {10}^{-11} {\mathrm{Nm}}^2{\mathrm{kg}}^{-2},$mass of earth $M=6\times {10}^{24 }\mathrm{kg}$, radius of Earth $R=6400 \mathrm{km}$)