Trucks can be run on energy stored in a rotating flywheel, with an electric motor getting the flywheel up to its top speed of 611 rad/s. One such flywheel is a solid, uniform cylinder with a mass of 465 kg and a radius of 1.8 m that rotates about its central axis. What is the kinetic energy of the flywheel after charging? Also If the truck uses an average power of 6.5 kW, for how many minutes can it operate between chargings? (No units required.)