
$\frac{1}{2} \mathrm{m} \omega^{2} \mathrm{A}^{2}=4$
$\frac{1}{2} m \omega^{2} A^{2} \times 25=4$
$\mathrm{m} \omega^{2}=\frac{8}{25}$
$F=-m \omega^{2}(y-5)$
$=-\frac{8}{25}(y-5)$
$y = \frac{1}{{\sqrt a }}\,\sin \,\omega t \pm \frac{1}{{\sqrt b }}\,\cos \,\omega t$ will be
$x = a\,\sin \,\left( {\omega t + \pi /6} \right)$
After the elapse of what fraction of the time period the velocity of the particle will be equal to half of its maximum velocity?

