Give two practical applications of reflection of sound waves.
(i) Reflection of sound is used to measure the speed and distance of underwater objects. This method is called SONAR.
(ii) Working of a stethoscope - the sound of patient’s heartbeat reaches the doctor’s ear through multiple reflections of sound.
Explain how the human ear works.
Explain how defects in a metal block can be detected using ultrasound.
A sonar device on a submarine sends out a signal and receives an echo 5 s later. Calculate the speed of sound in water if the distance of the object from the submarine is 3625 m.
Explain the working and application of a sonar.
How is ultrasound used for cleaning?