1 A uniform lamina is in the form of a sector of a circle with centre \(O\), radius 0.2 m and angle 1.5 radians. The lamina rotates in a horizontal plane about a fixed vertical axis through \(O\). The centre of mass of the lamina moves with speed \(0.4 \mathrm {~m} \mathrm {~s} ^ { - 1 }\). Show that the angular speed of the lamina is \(3.30 \mathrm { rad } \mathrm { s } ^ { - 1 }\), correct to 3 significant figures.