5
\includegraphics[max width=\textwidth, alt={}, center]{4cac1898-8251-4cda-bbbc-c2c30fde5a6e-2_618_627_1594_743} A uniform circular disc has mass 4 kg , radius 0.6 m and centre \(C\). The disc can rotate in a vertical plane about a fixed horizontal axis which is perpendicular to the disc and which passes through the point \(A\) on the disc, where \(A C = 0.4 \mathrm {~m}\). A frictional couple of constant moment 4.8 Nm opposes the motion. The disc is released from rest with \(A C\) horizontal (see diagram).

1. Find the moment of inertia of the disc about the axis through \(A\).
2. Find the angular acceleration of the disc immediately after it is released.
3. Find the angular speed of the disc when \(C\) is first vertically below \(A\).