Question

The figure shows mass $m$ with velocity $U$. Ring is restricted to move on smooth fixed horizontal rod. The velocity of ring at that moment is :

• A. $\frac{U}{2}$
• B. $2U$
• C. $\frac{2U}{\sqrt{3}}$
• D. $\frac{\sqrt{3}U}{2}$

Answer 1

The correct option is B $2U$

Velocity along string remains same.
$V_R\cos \theta =U$
$V_R=\frac{U}{\cos \theta }$
$\theta ={60}^{\circ }$
$V_R=2U$