Answer: 4500 metres
Step-by-step explanation:
Echo is a reflection of sound wave. It is the sound heard after it has been reflected off the surface of a wall or cliff.
Time = 6 seconds
Speed of sound in water = 1500m/s
distance =?
From the relationship ;
Speed = distance / time
Distance = speed * time
Distance = 1500 * 6 = 9000 metres
Distance here represents the total distance traveled by the pulse that is distance to the seafloor and back to the surface.
Therefore the depth of the water is given by;
Depth = distance / 2
Depth = 9000 / 2 = 4500metres.