question_answer 9)

For the wave described in Q.8 above, plot the displacement (y) versus (t) graphs for x=0, 2 and 4 cm. What are the shapes of these graphs ? In which aspects dose the oscillatory motion in travelling wave differ from one point to another : amplitude, frequency or phase ?                       

Answer:

The transverse harmonic wave is                                 For      x=0                   ??(i)                 Here,           For different values of t, we calculate y using eqn. (i). These values are tabulated below:

T	0	T/8	2T/8	3T/8
Y	3/	3	3/	0

 

4T/8	5T/8	6T/8	7T/8	T
-3/	-3	-3/	0	3/

On plotting y versus (graph, we obtain a sinusoidal curve as shown in Pig. 10(NCT).8. Similar graphs are obtained for x = 2 cm and .1=4 cm. The oscillatory motion in travelling wave differs from one point to another only in terms of phase. Amplitude and frequency of oscillatory motion remain the same in all the three cases.