$\mathrm{mg}-\mathrm{N}=\mathrm{m} \omega^{2} \mathrm{x}$
where $x$ is the distance from mean position
For block to leave contact $\mathrm{N}=0$
$\Rightarrow m g=m \omega^{2} x \Rightarrow x=\frac{g}{\omega^{2}}$
$Y = A \sin (\pi t +\phi)$, where time is measured in $second$.
The length of pendulum is .............$cm$
$y_1 = \sin \left( {\omega t + \frac{\pi }{3}} \right)$ and $y_2 = \sin \omega t$ is :
