List of top Science Questions on Propagation of Sound

Why is sound wave called a longitudinal wave?

Flash and thunder are produced simultaneously. But thunder is heard a few seconds after the flash is seen, why?

The frequency of a source of sound is 100 Hz. How many times does it vibrate in a minute?

A stone is dropped from the top of a tower 500 m high into a pond of water at the base of the tower. When is the splash heard at the top? 
Given, g = 10 ms^–2 and speed of sound = 340 ms^–1.

A sound wave travels at a speed of 339 ms^–1. If its wavelength is 1.5 cm, what is the frequency of the wave? Will it be audible?

What is loudness of sound? What factors does it depend on?