Re: Big Ben...

[Joseph Bellina <jbellina@saintmarys.edu>]

I suspect they are adjusting the center of mass of the physical 
pendulum...I doubt if it is an ideal pendulum in the sense that all the 
mass is in  the bob.  Thus changing the center of mass changes the 
effective length and hence the period.

cheers

On Sat, 28 Sep 1996, Delissa Souder 
wrote:

> 	Greetings!  I have a question that I'm hoping someone can help me 
> out.  I know that the period of a pendulum is dependent upon the length 
> of the pendulum and gravity. (T=2 x pi x (sqr rt. (length/gravity)))  I 
> was watching the Discovery channel and Would You Believe It was on.  They 
> were showing many neat, strange, and weird stuff.  They were talking 
> about some of the clocks and they showed the inside of Big Ben in 
> London.  They showed the pendulum in Big Ben with a small stack of old 
> pennies on it.  By adding or subtracting pennies on the bob of the 
> pendulum, they could adjust the period of the pendulum.  How is this so?  
> I've always thought the period of the pendulum is independent of its mass.
>
> Dwight
> dsouder@ashland.edu