A circular disc of radius R is rotating about its axis O with a uniform angular velocity `omega"rad s"^(-1)` as shown in the figure. The magnitude of the relative velocity of point A relative to point B on the disc is

Options

A. zero
B. `Romegasin((theta)/(2))`
C. `2Romegasin((theta)/(2))`
D. `sqrt3Romegasin((theta)/(2))`

Answer

C

Explanation

`|v_(AB)|=|v_(A)-v_(B)|=sqrt((Romega)^(2)+(Romega)^(2)-2(Romega)(Romega)costheta)`
`=2Romegasin.(theta)/(2)`