Answer to Question #115126 in Physics for Ding

Question

The moon with orbital radius from the earth centre is 384 000 km rotates the earth. Calculate time taken (in day) to orbiting the earth

Answer 1

$$T=2\pi\sqrt{\frac{R^3}{GM}}$$

$$T=2\pi\sqrt{\frac{(384\cdot10^{6})^3}{(6.67\cdot10^{-11})(5.97\cdot10^{24})}}\frac{1}{3600\cdot 24}=27.4\ days$$