## Essential University Physics: Volume 1 (3rd Edition)

We simplify the equation for the period of the pendulum so that length is isolated on one side of the equation: $L = \frac{T^2g}{4\pi^2}$ We plug in each of the values to find: a) $L = \frac{(200\times10^-3)^2(9.81)}{4\pi^2}=\fbox{.0099 meters}$ b) $L = \frac{(5)^2(9.81)}{4\pi^2}=\fbox{6.2 meters}$ c) $L = \frac{(120)^2(9.81)}{4\pi^2}=\fbox{3575 meters}$