Question

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Answer 1

Answer:

A:The number of times an object vibrates in one second is called frequency.The frequency of SI unit is "Hertz"

Answer 2

Answer:

A............Frequency is the speed of the vibration, and this determines the pitch of the sound. It is only useful or meaningful for musical sounds, where there is a strongly regular waveform. Frequency is measured as the number of wave cycles that occur in one second. The unit of frequency measurement is Hertz (Hz for short).

B........7Humans can detect sounds in a frequency range from about 20 Hz to 20 kHz.

C........i.....Since the sound wave produces 20 crests in 0.2 second, the density of the medium at a place becomes maximum 20 times in 0.2 second. The number of times it becomes maximum in 1 second is

20/0.2

10×10

So, the frequency is 100 times /second or 100 Hz....

ii..........Distance between two successive crust and trough is called wavelength...so wavelength equal to 100cm because distance between crest and trough is 50cm.....

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