A particle describes uniform circular motion in a circle of radius 2 m, with the angular speed of 2 rad `"s"^(-1)`. The magnitude of the change in its velocity in `(pi)/(2)` s is

Options

A. `a)0"ms"^(-1)`
B. `b)2sqrt(2) "ms"^(-1)`
C. `c)8"ms"^(-1)`
D. `d)4"ms"^(-1)`

Answer

C

Explanation

Given, `r=2m , omega = 2 "rads"^(-1) , t = (pi)/(2)` s
Now, ` theta = omega t = pi "rad"`
`v = r omega = 2xx`
`v= 4 "ms"^(-1)`
Now, `Delta v = 2v sin"" (theta)/(2)`
`Delta v= 2 xx 4 xx sin"" (pi)/(2)`
`Delta v = 8 "ms"^(-1)`