Question

Two small rings O and O' are put on two vertical stationary rods AB and A'B', respectively. One end of an inextensible thread is tied at point A'. The thread passes through ring O' and its other end is tied to ring O. Assuming that ring O' moves downwards at a constant velocity $v_1$, then velocity $v_2$ of the ring O, when $\angle$AOO' = $\alpha$,

• A.
• B.
• C.
• D. None of these

Answer 1

The correct option is A

$v_{2}cos\alpha +v_{1}cos\alpha =v_1\Rightarrow v_2=v_1[\frac{2si{n}^2\frac{\alpha }{2}}{cos\alpha }]$