Physics - Gravitation Question with Solution | TestHub

According to Kepler's second law, the angular momentum of the planet about the star is conserved. Therefore, at the minimum and maximum distances, the angular momentum must be equal. $L_1=L_2⟹m{v}_1{r}_1=m{v}_2{r}_2$. Solving for $v_2$, we get $v_2=v_1\frac{r_1}{r_2}$.