What Determines the Period of a Physical Pendulum?

[jbgibson]

Homework Statement

A physical pendulum is constructed using a 4.4 kg object having a moment of inertia of 33.9 kg-m2 about its center of mass. The rotation (suspension) point is 276.69 cm from the center of mass. What is the period of this physical pendulum?

Homework Equations

T = 2pi sq rt (I/mgh)

The Attempt at a Solution

Every attempt at this problem yields T = 3.35s. I did a little research to make sure I was using the correct equation, but I didn't find anything to contradict what I'm using. Inertia is kg-m^2; m=4.4kg, g=9.81m/s^2, and h=2.7669m. Any help is appreciated.

 

[Doc Al]

Note that I must be about the suspension point, not the center of mass.

 

[jbgibson]

Note that I must be about the suspension point, not the center of mass.

That's it! I worked out the problem using I about the suspension point and it's correct. Thank you for the insight.