3.20

T = 2 π \sqrt{\frac{r^{3}}{G M}}

${T = {2}{\pi} \sqrt {\frac{{{r^3}}}{{{G}{M}}}}}$

T = 2 π \sqrt{\frac{r^{3}}{G M}}

$T = {2}{\pi} \sqrt {\frac{{{r^3}}}{{{G}{M}}}}$

T (s)

$T \;\left(s\right)$

r (m)

$r\;\left(m\right)$

r

$r$

m

$m$

638000