physics force and work?

Question

a flywheel of radius .58m and moment of inertia of 17kg*m^2 rotates initially at a rate of 4.5 rev/sec. If a force of 4.8N is applied tangentially to the flywheel to slow it down, how much work will be done by this force in bringing the flywheel to a stop?

Answer 1

To bring the flywheel to a stop ( assuming no help from friction ) the work done will equal the kinetic energy of the flywheel which is (1/2) I {(omega)^2} where I is the moment of inertia and omega is the rotational velocity.