Sound of explosions taking place on other planets is not heard by a person on the Earth. Give the reason.

What is a longitudinal wave?

The stem of a tuning fork is pressed against a table top. Answer the following questions:
$(i)$ Would the above action produce any audible sound?
$(ii)$ Does the above action cause the table to set into vibrations?
$(iii)$ If the answer above is yes,what type of vibrations are they?
$(iv)$ Under what conditions does the above action lead to resonance?

What is echo ranging? State any one application of this technique.

State whether the following statement is true or false:
The minimum distance between a source and the reflector of sound should be $34\, m$.

Infrasound can be heard by