From: CGDonahoe3@aol.com
Date: Thu Nov 30 2000 - 15:55:55 PST
From: CGDonahoe3@aol.com Message-ID: <17.e3b03c4.2758430b@aol.com> Date: Thu, 30 Nov 2000 18:55:55 EST Subject: Re: pinhole Student Questions
Question 2: Why haven't your students asked why a voice gets "Donald Ducky"
when helium is inhaled?
Same answer as with the helium balloon. Helium's mass is less than the mass
of air we normally inhale. Hence, it is less dense.
When exhaling helium (speech) passes over the vocal cords, the cords
encounter a less dense gas and vibrate at a higher frequency.
Have you tried weighing/massing a balloon of air against a balloon of
Helium--given that the balloons have the same mass and are filled to equal
diameters. This would help demonstrate the difference.
Oh, by the way, be sure to use equal amounts of tape to secure the balloons
so the Heliium balloon does not float away.
Or use equal lengths/masses of thread to attach each to a simple scale and
observe.
enjoy
cgd3
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