A flywheel in the form of a heavy circular

disk of diameter 0.83 m and mass 111 kg is
mounted on a frictionless bearing. A motor
connected to the flywheel accelerates it from
rest to 1430 rev/min.
a)What is the moment of inertia of the fly-
wheel?
Answer in units of kg · m2

b) After 1430 rev/min is achieved, the motor is
disengaged. A friction brake is used to slow
the rotational rate to 834 rev/min.
What is the magnitude of the energy dissi-
pated as heat from the friction brake?
Answer in units of J