Final answer:
The time it takes for a dolphin to hear an echo of its sound in 25°C sea water after emitting it toward the bottom of the ocean 150 meters below is approximately 0.1961 seconds.
Step-by-step explanation:
To compute the time it takes for a dolphin to hear an echo of its sound directed toward the bottom of the ocean, we must consider that the sound has to travel to the bottom and then back up to the dolphin.
Since the distance to the bottom is 150 meters, the total distance traveled by the sound is twice this, which is 300 meters. We can calculate the time it takes for the sound to travel this distance by using the speed of sound in sea water at 25°C, which is given as 1530 m/s.
The formula we use is:
Time = Distance ÷ Speed
The total distance is 300 meters (150 m down and 150 m up), and the speed of sound is 1530 m/s.
Therefore,
Time = 300 m ÷ 1530 m/s
Time = 0.1961 seconds (approximately)
Thus, it takes approximately 0.1961 seconds for the dolphin to hear the echo.