JAMB - Physics (1979 - No. 42)
In a resonance tube experiment, which is illustrated above, the velocity of sound in air is 327.68m/s, the frequency of the turning fork used is therefore?
128HZ
256HZ
512HZ
768HZ
1024HZ
解释
for close pipes, the frequency is given as F=nv/4l while for opened pipes it is f=nv/2l
the number of harmonics,n is 1. Which is the fundamental note.
f=1 X 327.68 /4 X 0.16
f=327.68/0.64
f=512HZ