vibrations and sound
Quiz yourself by thinking what should be in
each of the black spaces below before clicking
on it to display the answer.
Help!
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sound | a mechanical wave that is produced by vibrating objects
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accoustics | the study of sound
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fundamental frequency | the frequency at which a body tends to vibrate if it is free to do so
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harmonics | frequencies that are multiples of the fundamental frequency. f is first harmonic, 2f is second harmonic etc
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overtones | frequencies which are multiples of the fundamental frequency. 2f is the first harmonic, 3f is the second harmonic
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resonance | the response of a body to vibrations of its own natural frequency. resonance occurs when a body is forced to vibrate at its own natural frequency, resulting in large amplitude oscillations and maximum energy transfer between forcing agent and object
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frequency limits of audibility | 20Hz to 20000Hz
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the human ear | is most sensitive to frequencies between 2kHz and 4kHz
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threshold of hearing | the smallest intensity audible by the average human ear at a frequency of 1kHz
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sound intensity | the energy per second passing through unit area perpendicular to the direction to which the sound is travelling
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sound intensity level | gives the intensity of sound relative to the threshold of hearing. if the sound intensity doubles, the sound intensity level decreases by 3dB.
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music | sound of a regular frequency, consisting of related frequencies such as fundamental and harmonics, with a periodic waveform
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noise | sound with a constantly varying frequency and with no repetition or pattern in the waveform
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demo: to show that sound needs a medium to travel | set up apparatus as shown with the bell jar ringing. air is removed from the bell jar using a vacuum pump. As air is removed, the loudness of the sound decreases until nothing is heard. conclusion: sound needs a medium to travel
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factors which determine the natural frequency |
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You may also shuffle the rows of the table by clicking on the "Shuffle" button.
Or sort by any of the columns using the down arrow next to any column heading.
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Created by:
erina27
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