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Re: [Phys-l] Another practical problem



This might be an excellent topic for student discussion at the high school level.
Some other discussion points lightly touched on in this interesting thread:

"Even a cast iron support showed increased loss with mass".
What is the Young's Modulus of cast iron compared to (say) mild steel?

"Pendulum supports can show increased loss with increased mass."
I assert that EVERY support holding a swinging pendulum provides a path for
energy dissipation which increases with swinging mass.

A design which arranges dual differential pendulums in antiphase was
one successful means of reducing the effects of support loss
to the desired value.

Why does increasing the mass of a dropped ball of constant size increase
its terminal velocity? Answering this question provides insight to
the effectiveness of increased pendulum bob weight, given suitably
insignificant support loss.

[Bernard, please discontinue forwarding to me, abusive private
notes from your circle of friends] :-)

Sincerely

Brian W

On 2/17/2011 2:54 PM, Bernard Cleyet wrote:
Comments?

Bryan means increasing the Q by increasing the mass has no effect. Increasing the Q by reducing the dissipation does,

bc

Begin forwarded message:

/snip/

You give a pendulum an impulse.
It swings to the other side.
It's energy is reduced by resistance to it's motion.
The weight of the bob in gravity doesn't matter. /snip/