Describe in brief, with the aid of a labelled diagram, an experiment to demonstrate that a material medium is necessary for the propagation of sound.

Describe an experiment to show that in wave motion, only energy is transferred, but particles of medium do not leave their positions.

How do the following factors affect, if at all, the speed of sound in air —

(i) frequency of sound
(ii) temperature of air
(iii) pressure of air
(iv) moisture in air?

Describe a simple experiment to determine the speed of sound in air. What approximation is made in the method described by you?