The homogeneous circular corona of the question 3 rotates about its axis of symmetry by making one revolution every $90s$ around the axis of symmetry. Determine magnitude of the angular momentum.

Data From Question 3:

Determine the moment of inertia of a homogeneous circular corona, of surface density $\sigma =1.25$ $kg{m}^{-2}$, with inner radius $r_1=0.30m$ and outer radius $r_2=0.50m$.