$T =2 \pi \sqrt{\frac{ L }{ g }}$
When lift is moving upwards $\Rightarrow$ Pseudo force acts downwards
$\Rightarrow g _{ eff }= g +\frac{ g }{2}=\frac{3 g }{2}$
$\Rightarrow$ New time period
$T ^{4}=2 \pi \sqrt{\frac{ L }{ g _{ eff }}}=2 \pi \sqrt{\frac{2 L }{3 g }}$
$T ^{\prime}=\sqrt{\frac{2}{3}} T$
where $A$ and $p$ are constant.
The period of small oscillations of the particle is

If the position and velocity of the particle at $t=0\, {s}$ are $2\, {cm}$ and $2\, \omega \,{cm} \,{s}^{-1}$ respectively, then its amplitude is $x \sqrt{2} \,{cm}$ where the value of $x$ is ..... .