$v=\frac{1}{2 \pi} \sqrt{\frac{\text { acceleration }}{\text { displacement }}}=\frac{1}{2 \pi} \sqrt{\frac{a}{x}}$
$\Rightarrow v=\frac{1}{2 \pi} \sqrt{\frac{k}{m}}$
$\Rightarrow \frac{k}{m}=\frac{a}{x} \Rightarrow \frac{k}{a}=\frac{m}{x} \Rightarrow v=\frac{1}{2 \pi} \sqrt{\frac{m}{x}}$
$\Rightarrow \frac{1}{2 \pi} \sqrt{\frac{10}{10^{-2}}}=\sqrt{\frac{10^{3}}{2 \pi}}=\frac{10 \sqrt{10}}{2 \pi}$
$=\frac{10 \times 3.16}{2 \times 3.14}=5 \mathrm{Hz}$
$\vec r = (\sin \,t\,\hat i\, + \,\cos \,t\,\hat j\, + \,t\,\hat k)m$
Find time $'t'$ when position vector and acceleration vector are perpendicular to each other