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Re: trebuchet

"Donald E. Simanek" wrote:
A friend of mine built what he calls a 'small' trebuchet with a 100 pound
counterweight which droped 3.5 feet. The sling and throwing arm measured
11 feet. It threw a 5 pound rock 69 feet from the pivot, a mass ratio
of 20 and an efficiency of 59%. Not bad.

Efficiency would be calculated how, exactly? I'm guessing that it's
(dE_projectile)/(dPE_counterweight). But everyone is reporting
projectile weight and range, which isn't enough to calculate the
numerator (I think...).

--
--James McLean
jmclean@chem.ucsd.edu
post doc
UC San Diego, Chemistry