A simple pendulum of length `l` is connected to the ceiling of a vehicle that is moving down along a smooth inclined plane with `sinx=4/5`. Then its period of oscillation is

Options

A. `2pi sqrt((5l)/(4g))`
B. `2pi sqrt((4l)/(5g))`
C. `2pi sqrt((5l)/(3g))`
D. `2pi sqrt((3l)/(5g))`

Answer

C

Explanation

`sin theta = (4)/(5) rArr cos theta = (3)/(5)`
`T = 2pi sqrt((l)/(g cos theta)) = 2pi sqrt((3l)/(5g))`