A particle takes a time `t_(1)` to move down a straight tunnel from the surface of earth to its centre. If gravity were to remain constant this time would be `t_(2)` calculate the ratio `(t_(1))/(t_(2))`

Options

A. `(pi)/(2sqrt(2))`
B. `(pi)/(sqrt(2))`
C. `sqrt(2)pi`
D. `(pi)/(sqrt(2))`

Answer

A

Explanation

`t=(T)/(4)=(2pi sqrt(R//9))/(4)=(pi)/(2)sqrt((R)/(g))rArr t'=sqrt((2R)/(g))`
`:. (t)/(t')=(pi)/(2sqrt(2))`