A $1\mathrm{.}4-$kg grindstone in the shape of a uniform cylinder of radius $0\mathrm{.}20$ m acquires a rotational rate

of from rest over a $6\mathrm{.}0-$s interval at constant angular acceleration. $($a$)$ Calculate the torque

delivered by the motor. $($b$)$ Calculate the net work done by the motor. $($Hint: The work equals the

change in the Kinetic energy$)$