New trends in physics teaching, v.4; The ... - unesdoc - Unesco

String and tape experiments
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Figure 12.
Figure 13.
through a hole in the bottom of a Styrofoam cup, as shown in the figure, or through a paper cone
which you can roll. This type of reed, in which the flap closes off the aperture completely, is
known as a 'beating reed', and is used in the clarinet, oboe and bassoon. The clarinet has one
reed, and the oboe and bassoon two reeds beating together.
One can make another type of beating reed from a drinking straw. Fold over the end of the
straw, as shown in figure 14a, and tape it closed. Take a razor blade, or sharp knife, and make
a rectangular cut about 2 to 3 mm wide, and 2 cm long. Put the whole of the reed in the mouth
and blow, as shown in the figure. It can generally be made to sound by very slightly lifting the
reed, and bending it up, so that when at rest the hole in the side is a little open. Such a reed is
very similar to that used in the drone of a bagpipe, or such antique instruments as the hornpipe.
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