A solid sphere of mass M and radius R is surrounded by a spherical shell of same mass M and radius 2R as shown. A small particle of mass m is released from rest from a height `h(lt lt R)` above the shell. There is a hole inn the shell.
QIn what time will it enter the hole at A

Options

A. `2(sqrt(hR^(2)))/(GM)`
B. `sqrt((2hR^(2))/(GM)`
C. `sqrt((hR^(2))/(GM))`
D. None of these

Answer

A

Explanation

`F=(G2Mm)/((R+R_(x))^(2))impliesa=(GM)/(2R^(2))`
`h=(1)/(2)at^(2)implies(4hR^(2))/(GM)=t^(2)impliest=2sqrt((hR^(2))/(GM))`