Question

17) State the conditions necessary of sound to be heard
​

Answer 1

(i) There must be a vibrating body which should be capable of transferring its energy to its surroundings. (ii) There must be a material medium to pick up energy and then propagate it in forward direction.

Answer 2

Answer:

source, medium and receiver.

Explanation:

source- where the sound is made.

medium- travel of sound from the object.

receiver- something to detect the sound.