If a particle rotates along a circle of radius 3 m with an angular acceleration of `(pi)/(2) "rad"//s^(2)` starting from rest, then its average velocity over the time it covers quarter circle is :

Options

A. `1 m//s`
B. `2 m//s`
C. `3 m//s`
D. `4 m//s`

Answer

C

Explanation

`theta = omega_(0) t + (1)/(2) alpha t^(2)`
`(pi)/(2) = 0 + (1)/(2) (pi)/(2) t^(2)`
`t = sqrt2`
average `v = (s)/(t) = (R sqrt2)/(sqrt2) = R = 3 ms^(-1)`