Question

It is said that minimum distance of abit 11 m airis necessary between the source of sound and reflector to hear and echo . Does it means that sound can be reflected from objects situated closer than 11 m

Answer 1

Explanation:

Uses of ultrasonic vibrations: Ultrasonic vibrations are used in SONAR to measure the depth of sea (or ocean) and to locate under water objects like submarines, sea-rocks and shipwrecks. It is used for scanning and imaging the position and growth of a foetus and presence of stones in the gall bladder and kidney.