A simple pendulum is oscillating with angular displacement `90^(@)` For what angle with vertical the acceleration of bob direction horizontal?

Options

A. `sin^(-1)(1/2)`
B. `cos^(-1)(1/3)`
C. `sin^(-1)(1/ sqrt3)`
D. `cos^(-1)(1/ sqrt3)`

Answer

`(4)`

Explanation

`tan theta = (a_(c))/ (a_(1)) = (v^(2)/r)/(g sin theta)`
but ` v^(2) = 2gh, h = r cos theta`