Chronology Current Month Current Thread Current Date
[Year List] [Month List (current year)] [Date Index] [Thread Index] [Thread Prev] [Thread Next] [Date Prev] [Date Next]

Re: [Phys-l] balloon floating in air in car



A little disappointing that no one seems willing to pick up on this as there is some good physics involved.

The accelerating car would set up a pressure wave in the air. The time to affect the balloon would be proporsional to the car's interior dimension divided by the speed of the pressure wave (speed of sound).

________________________________________
From: phys-l-bounces@carnot.physics.buffalo.edu [phys-l-bounces@carnot.physics.buffalo.edu] On Behalf Of John Denker [jsd@av8n.com]
Sent: Friday, April 24, 2009 1:55 PM
To: Forum for Physics Educators
Subject: Re: [Phys-l] balloon floating in air in car

On 04/22/2009 02:28 PM, Quist, Oren wrote:
I would venture that the tau depends upon the speed of sound in the
air in the car.

Indeed it does. That is a good place to start.

As the next step, to convert the speed of sound (c) to a time (tau),
we need a distance. A physically-relevant distance. Options
include:
-- Multiply c by the mean-free-path of the air molecules?
-- Multiply c by the diameter of the balloon?
-- Multiply c by the size of the car interior?
-- Bring in some other physics?


_______________________________________________
Forum for Physics Educators
Phys-l@carnot.physics.buffalo.edu
https://carnot.physics.buffalo.edu/mailman/listinfo/phys-l