$y_{2}=3(\sqrt{2} \sin 3 \pi t+\cos 3 \pi t)$
$=6\left[\frac{\sqrt{3}}{2} \sin 3 \pi t+\frac{1}{2} \cos 3 \pi t\right]$
$6\left[\sin \left(3 \pi t+\frac{\pi}{3}\right)\right]$
$=6 \sin \left(3 \pi t+\frac{\pi}{3}\right)$
ratio of their amplitude is $1 .$
Hence,
Option $A$ is correct answer.
Simultaneously at $t=0$, a small pebble is projected with speed $v$ from point $P$ at an angle of $45^{\circ}$ as shown in the figure. Point $P$ is at a horizontal distance of $10 \ cm$ from $O$. If the pebble hits the block at $t=1 \ s$, the value of $v$ is (take $g =10 \ m / s ^2$ )


