Give one use of ultrasound in industry and one in hospitals.

What is meant by the quality (or timbre) of sound? On what factor does the quality (or timbre) of a sound depend?

Explain why, if we strike a table lightly, we hear a soft sound but if we hit the table hard, a loud sound is heard.

How is it that bats are able to fly at night without colliding with other objects?

Explain how, bats use ultrasound to catch the prey.