Acceleration of a particle,executing $SHM$,at its mean position is

$A$ particle is executing $S.H.M.$ Then the graph of acceleration as a function of displacement is

$A$ body is executing $S.H.M.$ under the action of a force having a maximum magnitude of $50 \,N$. When its energy is half kinetic and half potential, the magnitude of the force acting on the particle is:

This is the position-time graph of a mass on a spring. What can you say about the velocity and force at the instant indicated by the dashed line? (Positive direction is to the right.)

$A$ horizontal platform with a small object placed on it executes a linear $S.H.M.$ in the vertical direction. The amplitude of oscillation is $40 \text{ cm}$. What should be the least period of these oscillations, so that the object is not detached from the platform (in $\pi \text{ s}$)? [Take $g = 10 \text{ m/s}^2$]

If a particle is executing simple harmonic motion,then the acceleration of the particle: