Oscillations
and Waves > Waves > Wave Properties of Sound
> Phase and Group
Velocity
DCS#
3B33.20
GROUP VELOCITY
APPARATUS
transparencies
202-21-C5
overhead projector
201
DESCRIPTION
The two transparencies have sets
of
parallel
lines with slightly different spacings. Overlay the
transparencies
on the overhead projector and move one with respect to the
other to
demonstrate the difference between the
phase velocity (that of the transparency) and the group
velocity
(that of the moire pattern).
