Date: Mon, 2 Feb 2004 14:27:49 -0800
Author: Doug Johnson
Subject: Re: vacuum bazooka
Post:
David,
My guess is that when you have multiple balls in the gun, that the
one ball closest to the end that is ruptured starts to turn and rub
against the next ball and climb up on it wedging itself between the
upper surface and the ball it is pushing. The second ball would want
to turn the opposite direction which would be creating a lot of
friction on the bottom of the tube. The more balls the greater the
friction.
My suggestion is to find some ping pong balls that are very smooth
and powder the balls and the tube with baby powder.
Best of luck! ...Doug J.
I'm working on getting a version of the ping pong ball/vacuum bazooka
on "The Tonight Show with Jay Leno", but their special effects team
have encountered some problems. They made a 10 foot bazooka from
smooth, clear plastic tube. It works with one ball, but they wish to
preferably use several balls at a time (TV always seems to want
everything "bigger"). Sometimes it works well with several balls, but
at other times the balls hardly move. Does anyone have any experience
using several balls and/or a smooth tube? Any advise on how to get this
demo to work well will be much appreciated (maybe a mention on the
show?) I have both five and ten foot versions in my lab, made from
white PVC that work well, except that the tape sometimes gets "sucked"
into the tube prematurly, I haven't had any problems with balls not
moving. I'm wondering if the somewhat dimpled surface on the inside of
the tubes I use may actually help. Any ideas?
cheers,
David Willey
P.S. I'm always looking for dramatic demos that we haven't done yet, if
you know of any suitable demos that are not on the following list I'd
love to hear about them.
Thank you all for your time, this is a great mailing list!!
Walking On Broken Glass
Dipping Hand In Molten Lead
Lying On A Bed Of Nails And Having A Concrete Block Smashed
Table Cloth Pull
Liquid Nitrogen And Packing Peanuts
Bowling Ball Pendulum
Hand On Fire Using Alcohol
Fire Tornado
Methane Mamba
Breathing Helium And Sulphur Hexaflouride
Thermite Reaction
Coffee Creamer Fireball
Smoke Ring Cannon
High Power Laser
Blowing Up A Pumpkin
Flame Oscilloscope
Colored Flames
Burning Magnesium In Carbon Dioxide
Walking On Eggs
Monkey And Gun
Blowing Up A Wedding Cake
55 Gallon Drum Collapse Using Steam
Ostrich Egg Into A Bottle
Toilet Paper Blower
Expanding Foam Columns
Shooting A Pencil Through A Board
Bike Wheel Twist To Show Conservation Of Angular Momentum
Hovercraft
Quicksand
Soda Bottle + Lifesavers Fountain
Bermuda Triangle
Burning Crackers In LOX
Aluminum And Chlorate Explosion
Chemiluminescence
Diaper Compound In Water
Latex Paint Cf. Cornstarch
Bicycle Wheel Gyroscopes
Square Wheeled Car
Rolling Chain
Cool-Gel
Cold Fire
Smoke And Fire Tornado
Liquid Nitrogen Cloud
Liquid Nitrogen Ice Cream
Balloons In Liquid Nitrogen
Methane Mamba Revisited
From pauld@exploratorium.edu Mon Feb 2 17:25:05 2004