Assume that a tunnel is dug across the earth. A ball is dropped into it. The time where it moves with a speed of sqrt(gR) is

Assume that a tunnel is dug across the earth. A ball is dropped into i

1.	Assume that a tunnel is dug across the earth. A ball is dropped into it. The time where it moves with a speed of sqrt(gR) is
Answer» `2pi SQRT((R )/(g))` `PI sqrt((R )/(g))` `pi/2 sqrt((R )/(g))` `pi/(sqrt2) sqrt((R )/(g))` ANSWER :C