Sonar machines in a fishing boat, received a single dose of the sea nasathon after sending a signal down to a time of 0.4 seconds, if the sound speed in water is 1500 much deep sea.
Sonar equipment on fishing boats receive signals reflected from the sea after the medicine go down, signaling for 0.4 seconds if the speed of sound in the ocean depths, how much water was in 1500.
The sonar in fishing boats have been reflected from the sea after the symbol ยาณ signal down for 0.4 seconds. If the speed of sound in water is 1500 sea depth is much.