In $S.H.M.$,maximum acceleration is at

The acceleration of a particle in $S.H.M.$ is

The oscillation of a body on a smooth horizontal surface is represented by the equation $x = A \cos \omega t$,where $x$ is the displacement at time $t$ and $\omega$ is the angular frequency of oscillation. Which one of the following graphs correctly shows the variation of acceleration $a$ with time $t$?

$A$ small wooden cube is placed on a plank. The plank performs a vertical $S$.$H$.$M$. of frequency $\frac{3}{\pi} \text{ Hz}$. The maximum amplitude of the plank so that the wooden block does not leave the plank is [take $g = 10 \text{ m/s}^2$].

For a particle performing Simple Harmonic Motion $(S.H.M.)$,the displacement-time graph is as shown. For that particle,the force-time graph is correctly represented by which of the following graphs?

The magnitude of maximum acceleration is $\pi$ times that of maximum velocity of a simple harmonic oscillator. The time period of the oscillator in seconds is