chapter eight solutions - Jay Mathy Science Wiki
... τapplied + τfriction = Iα1 with τapplied + τfriction = 36 N m.
Now in six seconds, ω changes from 0 to 10 rad/s.
Using ω = ω0 + α1t, we have 10 rad/s = 0 + α1(6 s), giving
α1 = 1.67 rad/s2. Then, 36 N m= (1.67 rad/s2)I, or I = 21.6 kg m2.
When the applied torque is removed, we have τfriction = Iα2.