The length of second's hand in watch is $1 \,cm.$ The change in velocity of its tip in $15$ seconds is
Zero
$\frac{\pi }{{30\sqrt 2 }}\,\,cm/\sec $
$\frac{\pi }{{30}}\,\,cm/\sec $
$\frac{{\pi \sqrt 2 }}{{30}}\,\,cm/\sec $
If position vector of a particle is $\left[ {(3t)\widehat i\, + \,(4{t^2})\widehat j} \right]$ , then obtain its velocity vector for $2\,s$.
A body starts from rest from the origin with an acceleration of $6 \;m / s^2$ along the $x$-axis and $8\; m / s^2$ along the $y$-axis. Its distance from the origin after $4\; seconds$ will be