Two spheres are each rotating at an angular speed of 25.0 rad/s about axes that pass through their centers. Each has a radius of 0.460m and a mass of 1.66 kg. However, as the figure shows, one is...

Two spheres are each rotating at an angular speed of 25.0 rad/s about axes that pass through their centers. Each has a radius of 0.460m and a mass of 1.66 kg. However, as the figure shows, one is solid and the other is a thin-walled spherical shell. Suddenly, a net external torque due to friction (magnitude = 0.360 N · m) begins to act on each sphere and slows the motion down. How long does it take
(a)
the solid sphere and
(b)
the thin-walled sphere to come to a halt?