$14)$Two planets $P_1$ and $P_2$ orbit around a star $S$ in circular orbits with speeds $v_1=46\mathrm{.}2k\frac{m}{s},$ and $v_2=59\mathrm{.}2k\frac{m}{s}$ respectively.

$($a$)$ If the period of the first planet $P_1$ is $7\mathrm{.}10$ years, what is the mass of the star it orbits around?

$kg$

$($b$)$ Determine the orbital period of $P_2.$

$yr$