The point A moves with a uniform speed along the circumference of a...

The point $A$ covers $30 ° in 0 . 1s$.
Then, we have $\dfrac{\pi}{6}rad ⟶ 0 . 1s$.
Or $1rad ⟶ \dfrac{0 . 1}{\dfrac{\pi}{6}}s$
Or $2\pi in \to \dfrac{0 . 1 \times 6}{\pi} \times 2\pi$
Thus, time taken is $T = 1 . 2sec .</p><p>We know that$\omega = $\dfrac{2\pi}{T}<br />Then,$\omega = $\dfrac{2\pi}{1 . 2}<br />Restoration force$( F ) = {m \omega}^{2}A .

Then Restoration force per unit mass \left(\dfrac{F}{m}\right) = {\omega}^{2}A$<br />\left(\dfrac{F}{m}\right) = {\left(\dfrac{2\pi}{1 . 2}\right)}^{2} \times 0 . 36$

$≅ 9 . 87N$