A circular saw blade accelerates from rest to an angular speed of $3620$ rpm in $6\mathrm{.}30$ revolutions. $($a$)$ Find the torque exerted on the saw blade, assuming it is a disk of radius $15\mathrm{.}2$ cm and mass $0\mathrm{.}755$ kg$.($b$)$ Is the angular speed of the saw blade after $3\mathrm{.}15$ revolutions greater than, less than, or equal to $1810$ rpm$?$ Explain. $($c$)$ Find the angular speed of the blade after $3\mathrm{.}15$ revolutions.