The changes in pressure caused when molecules of air or fluid collide with one another then move apart again are called __________.
A)hertz
B)sound waves
C)decibels
D)pitch

Question

Quizplus · Accepted Answer

The changes in pressure caused by the collisions and movements of air or fluid molecules are what create sound waves. Therefore, B is the best choice. Hertz (A) refers to the frequency of sound waves, not the changes in pressure themselves. Decibels (C) and pitch (D) are both measurements of sound intensity and frequency, respectively, and do not refer to the physical changes in pressure that create sound waves.

The Changes in Pressure Caused When Molecules of Air or Fluid