Question $2(10$ points$)$

What is the time $($seconds$)$ required to stop the blade of a saw initially operating at the speed of $1250$ rpm $,$ through the bearing friction alone $(T=\mathrm{.}019$ in lbs $)?$

Assume:

combined weight of the blade and motor armature: $4\mathrm{.}2$ lbs radius of gyration of $1$ inch.