Question

A point mass m is attached at the end of a massless rod of length L. Other end of rod is hinged to frictionless hinge. Sudden velocity $V=\sqrt{\frac{9gL}{2}}$ is provided to the point mass as shown in figure. So hinge reaction when this rod rotates by ${180}^0$ is

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

Answer 1

The correct option is D $\frac{mg}{2}$



$Byconservationofenergy\Rightarrow \frac{1}{2}m{v}_o^2=\frac{1}{2}m{v}^2+2mgL\Rightarrow v=\sqrt{\frac{gL}{2}}No\mathrm{w,}mg-N=\frac{m{v}^2}{L}\Rightarrow N=\frac{mg}{2}$