A block of mass m = 1   kg slides with velocity v = 6   m   s - 1 on a frictionless…

A block of mass $\mathrm{m}=1 \mathrm{kg}$ slides with velocity $\mathrm{v}=6 \mathrm{m} {\mathrm{s}}^{-1}$ on a frictionless horizontal surface and collides with a uniform vertical rod and sticks to it as shown. The rod is pivoted about $\mathrm{O}$ and swings as a result of the collision making angle $\theta$ before momentarily coming to rest. if the rod has mass $M=2 \mathrm{kg},$ and length $\ell =1 \mathrm{m},$ the value of $\theta$ is approximately$\left.(\mathrm{take} \mathrm{g}=10 \mathrm{m} {\mathrm{s}}^{-2}\right)$