109. (a) Eq. 15-28 gives T = 2Ď€
L 17m = 2Ď€ = 8.3 s. g 9.8 m / s 2
(b) Plugging I = mL2 into Eq. 15-25, we see that the mass m cancels out. Thus, the characteristics (such as the period) of the periodic motion do not depend on the mass.