The pelvic cavity contains the reproductive organs, urinary bladder, colon and rectum. Pelvic cavity is formed or bounded by three bone pairs called ilium, pubis and ischium.
Here, Amplitude mainly describes the intensity of sound we hear, They are directly proportional to each other. In other words, If Amplitude of the sound in greater, then you'll hear loud sound, vice-versa.
Frequency is the pitch of a sound. Change in frequency will change the pitch, and particularly for intensity, it doesn't affect loudness of the sound
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The reason why the nurse implemented this method is to ease the pain of the patient. Because of the severe burn, any concentrated pressure on any part of the damage skin will be very painful to the patient. Thus, the major function of the circulating air bed is to distribute the weight of the patient uniformly so that no single contact point with the bed will press harder than any other.