Question

ques-a) how are ultrasonic waves different from ordinary sound waves ? state two application of ultrasound. b) a ship sends out ultrasound that returns from the sea bed and is detected after 1.71 sec . if the speed of ultrasound through sea water is 1560m/s .calculate the depth of sea bed from the ship

Answer 1

a) ultrasonic waves are the waves which have frequency above 20,000 Hz and have higher penetrating power but the ordinary waves have different frequency from ultrasonic waves which is not more than 20,000 Hz.
application:-
1)ultrasonic waves used in SONAR to measure the depth of sea.
2)ultrasonic waves used in industries for detecting flaws and cracks in solid objects.
b)now the total time which is taken to travel return from the sea bed by the wave will be 1.71s=1.71/2=0.855s
speed of wave in water = 1560m/s
depth of sea bed from ship = ?
distance = speed*time
distance = 1560*0.855
so the depth (distance) = 1333.8metres