2
\includegraphics[max width=\textwidth, alt={}, center]{dd23f4a8-f7e7-4f80-bad6-7e9ec21565fc-2_465_643_495_749} A uniform right-angled triangular lamina \(A B C\) with sides \(A B = 12 \mathrm {~cm} , B C = 9 \mathrm {~cm}\) and \(A C = 15 \mathrm {~cm}\) is freely suspended from a hinge at its vertex \(A\). The lamina has mass 2 kg and is held in equilibrium with \(A B\) horizontal by means of a string attached to \(B\). The string is at an angle of \(30 ^ { \circ }\) to the horizontal (see diagram). Calculate the tension in the string.