How do I know that equation is good to use? Simple - it agrees with experimental evidence. So, for the rest of this post, I am going to use that equation of motion as though it were a real pendulum.

IT may interest some of your readers to know that they can for themselves observe in the most accurate manner the motion of the compound pendulum described by Mr H. Airy* by merely attaching the ...

HAVING read with much interest Mr. Hubert Airy's communication to NATURE (NO. 94), on “Pendulum Autographs,” I wish to say a word on the compound pendulum long ago devised, I believe for the ...