A disc in which serval grooves are cut along the chord drawn from a point 'A', is arranged in a vertical plane several particles starts slipping from 'A' along the grooves simultaneously. Assuming friction and resistance negligible, the time taken in reaching the edge of disc will be :-

Options

A. Maximum in groove AB
B. Maximum in groove AD
C. Same in all groove
D. According to the heights of B,C,D,E,F

Answer

C

Explanation

Using `s=ut+(1)/(2)at^(2)`
`2r cos theta=0+(1)/(2)g cos thetat^(2)`
`t=sqrt((4r)/(g))=` constant
which does not depend upon `theta`