A block of mass $m$ is placed on a frictionless surface and is attached to a spring with a spring constant $k$. The block is displaced by a distance $A$ from its equilibrium position and released from rest. Find the acceleration of the block at $t = 0$.
The force on the block due to the spring is given by Hooke's law: A block of mass $m$ is placed on
$a = \frac{F}{m} = -\frac{k}{m}x$