Two identical discs of same radius `R` are rotating about their axes in opposite directions with the same constant angular speed `omega`. The discs are in the same horizontal plane. At time `t = 0`, the points `P` and `Q` are facing each other as shown in the figure. The relative speed between the two points `P` and `Q` is `v_(r)`. In one time period (`T`) of rotation of the discs, `v_(r)` as a function of time is best represented by

Options

A.
B.
C.
D.

Answer

A

Explanation

`V_(r) =|2v sin theta| =|2v sin omega t|`