According to Kepler's law of planetary motion, if T represents time period and `r` is orbital radius, then for two planets these are related as

Options

A. `((T_(1))/(T_(2)))^(3//2)=(r_(1))/(r_(2))`
B. `(T_(1))/(T_(2))=[(r_(1))/(r_(2))]`
C. `[(T_(1))/(T_(2))]^(2)=[(r_(1))/(r_(2))]^(3)`
D. `(T_(1)^(2))/(T_(2))=(r_(1)^(3))/(r_(1))`

Answer

C

Explanation

By Kepler's third law of planetary motion, `T^(2) prop R^(3)`
`[(T_(1))/(T_(2))]^(2)=[(r_(1))/(r_(2))]^(3)`.