1 A circular flywheel of radius 0.3 m , with moment of inertia about its axis \(18 \mathrm {~kg} \mathrm {~m} ^ { 2 }\), is rotating freely with angular speed \(6 \mathrm { rad } \mathrm { s } ^ { - 1 }\). A tangential force of constant magnitude 48 N is applied to the rim of the flywheel, in order to slow the flywheel down. Find the time taken for the angular speed of the flywheel to be reduced to \(2 \mathrm { rad } \mathrm { s } ^ { - 1 }\).