(d) If speed of a wave in any medium is independent of frequency, then mediums called non-dispersive. For example, air is a non-dispersive medium for sound waves.
(e) The speed of light (3 × 108m/s) is much greater than the speed of sound (340m/s). So, the flash of light reaches us much earlier than the sound of thunder.
(f) The wave velocity is constant v = fλ in a given medium while the particle velocity changes harmonically with time. The particle velocity is zero at the extreme position.
