A point P `(Rsqrt(3)m,0,)` lies on the axis of a ring of mass M and radius R. The ring is located in `y -z` plane with its centre at origin. A small particle of mass m start from P and reaches O under gravitational attraction only. Its speed at O will be.

Options

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

Answer

A

Explanation

`("Total Mechanical Energy")_(P)=("Total Mechanical Energy")_(O)`
`implies (GMm)/(2R)=1/2 mv^(2) -(GMm)/R`
`impliesv=sqrt(((GM)/R)`