What is the audible range of the average human ear?

Why is a sound wave called a longitudinal wave?

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

Does sound follow the same laws of reflection as light does? Explain.

$A$ 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 (in $sec$) at the top?
Given,$g = 10\, m\, s^{-2}$ and speed of sound $= 340\, m\, s^{-1}$.

Explain how defects in a metal block can be detected using ultrasound.