Message-Id: <v01540b04afcc9d061cad@[192.174.2.173]>
Date: Tue, 17 Jun 1997 12:04:02 -0800
To: pinhole@exploratorium.edu
From: pauld@exploratorium.edu (Paul Doherty)
Subject: Re: help on catapults
Hello
We used surgical rubber tubing available at large home depot like stores.
about a 5 meter length of /14 or 3/8 inch tubing.
The tubing goes through holes drilled in the rim of the bowl. Then crosses
behind the bowl making an X. This is essential to produce a stable launch.
You can measure the force F needed to stretch the rubber a given distance,
d. Calculate the work done W = 1/2 F * d
set this equal to kinetic energy 1/2 m v*v of the launched balloon.
Then calculate the launch speed .
Paul D