Alarge, 42.0 kg bell is hung from a wooden beam so it can swing back and forth with negligible friction. the bell's center of mass is 0.80 m below the pivot. the bell's moment of inertia about an axis at the pivot is 18.0 kg⋅m2. the clapper is a small, 1.8 kg mass attached to one end of a slender rod that has length l and negligible mass. the other end of the rod is attached to the inside of the bell; the rod can swing freely about the same axis as the bell. what should be the length l of the clapper rod for the bell to ring silently that is, for the period of oscillation for the bell to equal that of the clapper?