Question

$\pi$

 .if a plnet of mass m is revolving around the sun in a circular orbit of radius r with time period T then mass of the sun is

Answer 1

Let mass of sun = M
mass of planet = m
Time period = T
radius = r

$T=2 \pi \sqrt{ \frac{r^3}{GM} } \\ \\ \Rightarrow T^2=4 \pi ^2(\frac{r^3}{GM})=\frac{4 \pi ^2r^3}{GM}\\ \\ \Rightarrow M= \frac{4 \pi ^2r^3}{GT^2}$