A particle of mass 100 g is projected at time t =0 with a speed 20 ms^-1 at an angle 45^° to the horizontal as given in the figure. The magnitude of…

A particle of mass $\displaystyle 100$ g is projected at time $\displaystyle \mathrm{t}=0$ with a speed $\displaystyle 20 \mathrm{~ms}^{-1}$ at an angle $\displaystyle 45^{\circ}$ to the horizontal as given in the figure. The magnitude of the angular momentum of the particle about the starting point at time $\displaystyle \mathrm{t}=2 \mathrm{~s}$ is found to be $\displaystyle \sqrt{\mathrm{K}} \mathrm{kg} \mathrm{m}^2 / \mathrm{s}$. The value of K is $\displaystyle \_\_\_\_$. (Take $\displaystyle \mathrm{g}=10 \mathrm{~ms}^{-2}$ )