- #71

The particle goes on with the velocity at the moment you cut the string. At this moment the velocity was perpendicular to the radius vector since the tangent of a circle is always perpendicular to the radius...

I think we have ##v_r = v\sin{\theta}## if the string is cut when ##\theta = 0##. Then ##v_r## approaches (increasing) to ##v## as ##\theta \rightarrow \frac{\pi}{2}##.