Explain how:

(i) A sound wave’s pressure antinode is a displacement node and vice versa.

(ii) The Ganges river dolphin despite being blind, can manoeuvre and swim around obstacles and hunt down preys.

(iii) A guitar note and violin note are being played at the same frequency, however, we can still make out which instrument is producing which note

(iv) Both transverse and longitudinal wave can propagate through solids, but only longitudinal waves can move through gases.

(v) In a dispersive medium, the shape of a pulse propagating through it gets distorted.

Asked by Pragya Singh | 1 year ago |  163

1 Answer

Solution :-

(i)  An antinode is a point where pressure is the minimum and the amplitude of vibration is the maximum. On the other hand, a node is a point where pressure is the maximum and the amplitude of vibration is the minimum.

(ii) The Ganges river dolphin sends out click noises which return back as vibration informing the dolphin about the location and distances of objects in front of it. Thus, allowing it to manoeuvre and hunt down preys with minimum vision.

(iii) The guitar and the violin produce overtones of different strengths. Thus, one can differentiate between the notes coming from a guitar and a violin even if they are vibrating at the same frequencies.

(iv) Both solids and fluids have a bulk modulus of elasticity. Thus, they both allow longitudinal waves to propagate through them. However, unlike solids, gases do not have shear modulus. Thus, transverse waves cannot pass through gases.

(v) A pulse is a combination of waves of un-similar wavelengths. These waves move at different velocities in a dispersive medium. This causes the distortion in its shape.

Answered by Abhisek | 1 year ago

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