Question

Two asteroids are separated by a distance of 42.0 m. If one asteroid has a mass of 2.22 x 109 kg and the other asteroid has a mass of  9.87 x 108 kg, what is gravitational force between them?

Answer 1

The gravitational force between two asteroids is given by the Newton's law:

$$F = G\dfrac{m_1m_2}{r^2}$$

where $m_1 = 2.22\times 10^9 kg$, $m_2 = 9.87\times 10^8kg$ are masses of the asteroids, $r = 42m$ is the distance between the asteroids, and $G = 6.67\times 10^{-11}m^3kg^{-1}c^{-2}$. Combining it all together, obtain:

$$F = 6.67\times 10^{-11}\cdot \dfrac{2.22\times 10^9\cdot 9.87\times 10^8}{42^2} \approx 7.73\times 10^4N$$

Answer. $7.73\times 10^4N$.