Oscillations and Waves > Waves > Phase and Group Velocity

DCS# 3B30.20

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SPEED OF SOUND IN AIR

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APPARATUS

storage scope with camera or teamlabs set-up	202-08-D-1
pair of microphones	202-07-E1
two wooden blocks	202-01
tape measure	101-05-E2

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DESCRIPTION

Set microphones a known distance apart.  Clap the wooden blocks together.  Measure the time difference between the peaks on the scope and calculate the speed of sound in air.

Five meters is a convenient distance to use as it yields a time difference of 15 ms, which spans the scope screen with the sweep rate set to 2 ms/div.