Experiment 5 : Introduction to Sound

In this lab, different frequencies were compared by observing the graph for each frequency. For all the different graph of frequencies, the frequencies were created by different voices made by human and also the tuning fork. First, in order to analyze the frequency, one person needed to say "AAA" into the voice detector, after that the other person with different voice would also say "AAA" to the voice detector. From these two obtained graph, different pitch of the voice could be analyzed by the graphs produced by different frequency of the voice. After obtaining voice produced by the human, the tuning fork was used to create the sound so that different pattern of the frequency could be obtained. With all the obtained graphs, numbers of waves, the period of those waves, the frequency of those waves, and the amplitude of thoes waves should all be calculated or analyzed. The numbers of the wave would be determined by counting the numbers of the repeated pattern on the graph. Then the time taken by one wave could also be obtained from the graph. After obtaining the time, the equeation 1/T would be applied to calculate the frequency of the wave. The amplitude would also be calculated with all the obtained data.

Figure 1. Sound produced by one person talked to the voice detector (lower frequency)

 Figure 2. Sound produced by the other person talked to the voice detector (higher frequency)

Figure 3. Sound produced by tuning fork striking on a soft object

From the above graphs, we notice that the sound graph is a periodic wave. it shows that the graphs go to a higher position than go down gradually with several curves, then the pattern would repeat with the sound goes on. From the graphs above, figure one shows that the sound produced about three waves in 0.027(s), and the figure 2 shows that the sound made by the second person produced about six waves in 0.03(s). From here, we notice that the second person had higher frequency, hence higher velocity. 
Since three waves were produced in 0.027 (s) in figure 1, frequency could be calculated by applying 1/T, so the frequency obtained for the figure one would be 111.11 (Hz).
To answer question f, which the speed of sound was assumed to be 340m/s, what would the wavelengh be? Here the equarion v=fλ would be applied to calculate the λ, the equation was rearranged and appeared to be λ=v/f, in whice velocity of sound, 340 m/s and frequency obtained earlier, 111(Hz) were substituted in the equation. The final obtained answer for wavelengh then would be 3.06 (m).


For figure 2, five waves were produced in about 0.025 seconds, which means the time taken for a wave to go was 0.005 seconds. Therefore, the frequecny could also be obtained by applying the equarion used for figure one, the frequency in this case would be 200(Hz), so the wavelengh in this case would be 1.7 (m).



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	Time (s)	Frequency(Hz)	Wavelength(m)
Figure 1	0.009±0.0005	111±0.5	3.06±0.005
Figure 2	0.005±0.0005	200±0.5	1.70±0.005

By obseving figure 3, we notice that the curves, or the waves went regularly and constantly. The result turned out as expected that the tuning fork prouced the sound with constant frequency.
If we use the same tuning fork to collect data for a sound that is not as loud, then the amplitude of the wave should be smaller. The answer was given because higher volume has larger amplitude and lower volume has smaller amplitude.