Two starts each of one solar mass `(=2xx10^(30)kg)` are approaching each other for a head on collision. When they are a distance `10^(9)`km. their speeds are negligible. What is the speed with which they collide? The radius of each star is `10^(4)`km. Assume the stars to remain undistorted until they collide. (Use the known value of G).

Options

A. `sqrt((GM)/(R ))`
B. `sqrt((GM)/(2R ))`
C. `sqrt((GM)/(4R))`
D. `sqrt((2GM)/(R ))`

Answer

B

Explanation

`sqrt((GM)/(2R ))`