A physical pendulum is any extended object.

For a physical pendulum   ω

=

(

m g h I

)

½

Here h is the distance from the rotation point to the pendulum's center of gravity.

Example:  A rod of length L supported at one end.

h

=

L 2

and

I

=

1 3

mL2

This gives an angular frequency of:

ω

=

(

3g 2L

)

½

the same frequency as a simple pendulum of length of 2L/3.