Calculate the gravitational force of attraction between two objects separated by a distance of $1.0\mathrm{cm}$ and each having a mass of $100 \mathrm{g}$.

Calculate the gravitational force of attraction between two asteroids separated by a distance of $4.0\times {10}^9\mathrm{m}$ and each having a mass of $5.0\times {10}^{10}\mathrm{kg}$.

Calculate the gravitational force of attraction between a satellite of mass $1.4 \mathrm{x}{10}^4 \mathrm{kg}$ orbiting the Earth at a distance of $6800 \mathrm{km}$ from the Earth's centre. (The mass of the Earth is$6.0\times {10}^{24}\mathrm{kg}$).

Calculate the gravitational field strength close to the surface of the Moon.

Calculate the gravitational field strength close to the surface of the Sun. 

Calculate the Earth's gravitational field strength at the position of the Moon.