# Homework Help: Frequency of Oscillation of a monkey hanging from a tree

1. Oct 28, 2009

### forddj

1. The problem statement, all variables and given/known data

A gibbon, hanging onto a horizontal tree branch with one arm, swings with a small amplitude. The gibbon's center of mass is 0.410 m from the branch and its rotational inertia divided by its mass is I/m = 0.289 m2. Estimate the frequency of oscillation.

2. Relevant equations

d = 1/2L
T = 2π * SQRT(I/mgd)
f = 1/T

3. The attempt at a solution

Okay, they have given me I/m, and I need to find f using the last equation. In order to find T, I need to use the first and second equation.

d = 1/2(.410)
d = .205

I/m = .289 m2

T = 2π * SQRT([.289][9.8][.205])
T = 2π * .762
T = 4.78

f = 1/4.78
f = .209 Hz

Which is, of course, wrong. I'm thinking I'm getting confused by the I/m = 0.289 m2 value which is throwing off how I plug and chug. I may even have the wrong equation. Thanks for all your help.

2. Oct 28, 2009

### forddj

Nevermind, I solved it!