At a given instant, a disc is spinning with angular velocity \(\omega\) in a plane at right angles to the paper (see the Fig.74) and after a short interval of time \(\delta\) t, it is spinning with angular velocity \(\omega+\) \(\delta \omega\) and the axis of spin has changed direction by the amount \(\delta \theta\).

In this situation what is the component of acceleration parallel to \(O A\) ?

(a) \(\mathrm{d} \theta / \mathrm{d} t\)

(b) \(\omega(\mathrm{d} \theta / \mathrm{d} t)\)

(c) \(\mathrm{d} \omega / \mathrm{d} t\)

(d) \(\mathrm{d} \theta / \mathrm{d} \omega\)

90 Fig.74 00+800 A