I typically buy about two gross of the superbounce balls on the
order of 1 inch diameter (multiple color and the sparkle ones). I use
them to demonstrate how a gas molecule rebounds from the wall of a
container to produce pressure.
Along the lines of -> Imagine yourself as that door over there.
What would you feel if I bounced this ball off you? (Throw on ball at
door and catch it). What would happen if I bounced two balls at a time
off you (Throw two balls and catch them). So generalize: as I increase
the number of molecules (all else being equal), what happens to the
force/pressure? Then ask what would happen if I bounced a whole mess of
balls off the door (Reach down and grab a large handful and fling them
at the door). Then tell the students that if they catch one, they can
have it. Suitable for a classroom and probably not a lecture hall. The
effect of all those super bounce balls rebounding around the classroom
produces a suitable picture of gas molecules in flight (at least
momentarily).
They are also useful for asking: what would happen if I threw
the ball at the door faster? What if the ball were bigger? And, of
course, according to our model the molecules should stop bouncing
sometime. Why isn't all of the air in this room at floor level?
Shouldn't you be suffocating about now?
THO
Thomas O'Neill
Physics
Shenandoah Valley Governor's School
-----Original Message-----
From: phys-l-bounces@carnot.physics.buffalo.edu
[mailto:phys-l-bounces@carnot.physics.buffalo.edu] On Behalf Of Mark
Lucas
Sent: Friday, October 05, 2007 2:09 PM
To: Forum for Physics Educators
Subject: [Phys-l] Small, Inexpensive Physics Toys?
We are preparing for an open house and are looking for good ideas for
small 'prizes' to give to elementary or middle school aged kids. I'm
aware of the $3-4 bracket of things I can get at Arbor Scientific or
Educational Innovations (Energy Balls, Diffraction gratings, Dropper
Poppers, etc...), and I have the okay to pepper the pot with some of
these, but we were also looking for something more in the $1 (or
slightly less), since we aren't certain how many kids to expect.
We are aware of the Oriental Trading Company. The challenge with this is
to have something physics-oriented. We can purchase the slinkies or
gliders. Do people have other suggestions or vendors or specific little
'prizes' that would be appropriate for this situation?
I'd also be interested in suggestions in the $1-3 range.