1-7
Figure 1-6.—The three elements of sound.
Q8. What are the three requirements for a wave to be propagated?
TERMS USED IN WAVE MOTION
There are a number of special terms concerning waves that you should know. Many of the terms,
such as CYCLE, WAVELENGTH, AMPLITUDE, and FREQUENCY were introduced in previous
NEETS modules. We will now discuss these terms in detail as they pertain to wave propagation. Before
we begin our discussion, however, note that in the figure, wave 1 and wave 2 have equal frequency and
wavelength but different amplitudes. The REFERENCE LINE (also known as REST POSITION or
POINT OF ZERO DISPLACEMENT) is the position that a particle of matter would have if it were not
disturbed by wave motion. For example, in the case of the water wave, the reference line is the level of
the water when no wave motion is present. With this in mind, let’s go on to our discussion of the four
terms, as shown in figure 1-7.
