2 A uniform semicircular lamina of radius 0.25 m has diameter \(A B\). It is freely suspended at \(A\) from a fixed point and hangs in equilibrium.
- Find the distance of the centre of mass of the lamina from the diameter \(A B\).
- Calculate the angle which the diameter \(A B\) makes with the vertical.
The lamina is now held in equilibrium with the diameter \(A B\) vertical by means of a force applied at \(B\). This force has magnitude 6 N and acts at \(45 ^ { \circ }\) to the upward vertical in the plane of the lamina.
- Calculate the weight of the lamina.