Use the expression you wrote down in question $4)$ relating speed $($v$),$ period $($P$),$ and distance from the Sun $($R$),$ to eliminate P from the proportionality form of Kepler$$s Law $($P$2$ a$3).$ You should be left with an expression only in terms of speed $($v$)$ and distance $($R$).$ Simplify your answer.

$6)$ Rearrange this proportionality to solve for speed $($v$)$ in terms of distance $($R$).$