Wave Motion 1 Question 14
14. The amplitude of a wave disturbance travelling in the positive $x$-direction is given by $y=\frac{1}{(1+x)^{2}}$ at time $t=0$ and by $y=\frac{1}{\left[1+(x-1)^{2}\right]}$ at $t=2 s$, where $x$ and $y$ are in metre. The shape of the wave disturbance does not change during the propagation. The velocity of the wave is ….. $m / s$.
(1990, 2M)
Show Answer
Answer:
Correct Answer: 14. $2 \pi v A, 4 \pi^{2} v^{2} A$
Solution:
- In the question, it is given that the shape of the wave disturbance does not change, while in the opinion of author this is not true.
From the function, $y=\frac{1}{(1+x)^{2}}$, we can see that, at $x=-1, y=\infty$.
Whereas from the second function, $y=\frac{1}{\left[1+(x-1)^{2}\right]}$ we don’t get any point where $y=\infty$.
So, how can we say that shape has not changed.
