Question

A narrow sound pulse (for example, a short pip by a whistle) is sent across a medium. (a) Does the pulse have a definite (i) frequency, (ii) wavelength, (iii) speed of propagation? (b) If the pulse rate is 1 after every 20 s, (that is the whistle is blown for a split of second after every 20 s), is the frequency of the note produced by the whistle equal to or 0.05 Hz?

Answer 1

This is conceptual question. You should know that a non - dispersive wave motion refers to the motion of wave in which the wave disturbance doesn't change shape as it propagates .
It means all part of the wave travel in same speed . hence, the speed of a non-desperse wave depends only one the entire of the medium through which the wave travel not on the shapr or frequency Content of the wave form.

(a) the pulse frequency of pip by a whistle is caring of the source generating the pulse controls this phenomena randomly so, the wavelength also varies. But if it travels through non- dispersive medium the velocity of propagation remains constant . hence, frequency must change .

( b) this represent the frequency of reputation , not the frequency of the pulse , which is decided by the source producing the whistle parameters .
So, frequency of the note produced by wistle doesn't equal to 1/20 Hz

Answer 2

Answer:

A narrow sound pulse such as a short pip by a whistle does not have a definite wavelength or frequency, However being a sound wave, it has a definite speed.

Explanation: