A particle is given an initial speed `u` inside a smooth spherical shell of radius `R=1` m such that it is just able to complete the circle. Acceleration of the particle when its velocity is vertical is

Options

A. `gsqrt(10)`
B. g
C. `gsqrt(2)`
D. 3g

Explanation

`u^(2)=5gR`
`:.v^(2)=u^(2)-2gR`
`=5gR -2gR= 3gR`

Tangential acceleration at B is
`a_(1)=g` (downwards)
Centripetal acceleration at B is
`a_(c)=(v^(2))/(R)=3g`
`:.` Total acceleration will be
`a=sqrt(a_(c)^(2)+a_(1)^(2))=g sqrt(10)`