Question

What is the force exerted by Big Ben on the Empire State building? Assume that Big Ben

has a mass of 108 kilograms and the Empire State building 109 kilograms. The distance

between them is about 5000 kilometers and Big Ben is due east of the Empire State

building.

Answer 1

By the law of universal gravitation:

$$F=\frac{Gm_1m_2}{r^2}=2.7·10^{-7}\text{ N}.$$