Discuss analytically the formation of beats and show that the beat frequency
equals the difference in frequencies of two interfering waves.
Answers
Answer:
FORMATION OF BEATS
Beats are generated when two sounds have similar frequency. The effect is that
the sound’s amplitude or volume oscillates or beats. The beat phenomenon is
caused by constructive and destructive interference. The picture below shows
the beat generated by two tuning forks with very close frequencies.
The graph in the attachment is amplitude (sound pressure) vs. time. The period of the beat
is defined as the time from one peak to the next, or the time between
amplitude (volume) maximums.
BEAT FREQUENCY FORMULA
The simplest way to “derive” the beat frequency formula is by simple
observation - okay that sounds a bit cocky. But if you have microphone and a
few tuning forks or just a good ear and the ability to count accurately this
relation can be demonstrated pretty easy.
The applet below will allow you to "see" and hear beats. The two sliders allow
you to adjust the frequency of the tones. The more similar the frequencies the
easier the beats are to count accurately. However, a large difference (around
0.5 kHz or 500 Hz) allows you to "see" the difference given the window and
scale I choose for the applet. Play around.
By observation (i.e. data gathering) it can be found that the beat frequency is:
(1)
fb=|f1−f2|
Explanation:
Answer:
Explanation:quit