A planet moves around the Sun. It is closest to Sun at a distant `d_(1)` and has velocity `v_(1)` and farthest with distance `d_(2)`, its speed at this point will be:

Options

A. `(d_(1)^(2)v_(1))/(d_(2)^(2))`
B. `(d_(2)v_(1))/(d_1)`
C. `(d_(1)v_(1))/(d_2)`
D. `(d_(2)^(2)v_(1))/(d_(1)^(2))`

Answer

C

Explanation

By conversation of angular momentum,
`L_(1)=L_(2)(or)mv_(1)d_(1)=mv_(2)d_(2)," "thereforev_(2)=(v_(1)d_(1))/(d_2)`