The time taken by a particle to slide down a smooth inclined plane is double the time it would take in falling down through a height equal to the vertical height of the plane. The inclination of the plane with horizontal is :

Options

A. `30^(@)`
B. `45^(@)`
C. `60^(@)`
D. `90^(@)`

Answer

A

Explanation

`((h)/(sin theta)) = (1)/(2) (g t_(1)^(2)) sin theta`
`h = (1)/(2) g t_(2)^(2)`
`t_(1) = 2t_(2)`