1. The problem statement, all variables and given/known data A holiday ornament in the shape of a hollow sphere with mass 1.0×10−2 kg and radius 5.0×10−2 m is hung from a tree limb by a small loop of wire attached to the surface of the sphere. If the ornament is displaced a small distance and released, it swings back and forth as a physical pendulum. Calculate its period. (You can ignore friction at the pivot. The moment of inertia of the sphere about the pivot at the tree limb is (5/3)MR^2.) 2. Relevant equations T = 2Pi*(sqrt(I/mgL)) 3. The attempt at a solution This is the only formula I know for the period, but the problem doesn't give the value of L. Is there another formula for the period?