Find the speed of the ring as a function of '`theta`' if rope is pulled down with constant speed u:-

Options

A. `(u)/(sin theta)`
B. `(u)/(cos theta)`
C. `(u)/(2 sin theta)`
D. `(u)/(2 cos theta)`

Answer

B

Explanation

Let speed of ring he v then ` v cos theta=u rArr v=(u)/(cos theta)` (`because` Magnitude of velocity along the string of any two points on string is same.)