Question

Sound is produced when a body undergoes to and fro movements . However no sound is produced when a person wave his hand .why

Answer 1

Answer:

I may not be right , sorry for that

sound is produced by these movements but when the force applied is very less then the movement of air particles is also negligible . Thus sound doesn't reach our ear drum.Thus we cannot hear it.

Bring your hand near to your ear , wave it at the speed of at least 3 to and fro movements within a second and believe me you gonna hear that relaxing voice