A solid sphere of mass M and radius R is surrounded by a spherical shell of same mass and radius 2R as shown. A small particle of mass m is relased from rest from a height h`(lt lt R)` above the shell. There is a hole in the shell.
Q. With what approximate speed will it collide at B?

Options

A. `sqrt((2GM)/(R))`
B. `sqrt((GM)/(2R))`
C. `sqrt((3GM)/(2R))`
D. `sqrt((GM)/(R))`

Answer

D

Explanation

COME `implies0-(G(2M)m)/((2R+h))=(1)/(2)mv^(2)-(GMm)/(R)-(GMm)/(2R)`
`impliesvcongsqrt((GM)/(R))`