A dolphin swimming in seawater at a temperature of 25degree Celsius emits a sound directed toward the bottom of the ocean 150 meters below. what period of time passes befor it hears an echo?

To calculate the time it takes for the dolphin to hear the echo, we need to consider the speed of sound in seawater.

The speed of sound in seawater varies depending on several factors, including temperature, pressure, and salinity. The average speed of sound in seawater at 25 degrees Celsius is approximately 1,500 meters per second.

To determine the time it takes for the sound to reach the bottom and then return as an echo, we can use the fact that the distance traveled is twice the distance from the dolphin to the bottom: 150 meters down and 150 meters back up.

Let's calculate the time using the formula: time = distance / speed.

First, we calculate the time it takes for the sound to reach the bottom:
time_down = 150 meters / 1,500 meters per second = 0.1 seconds.

Next, we calculate the time it takes for the sound to return as an echo:
time_up = 150 meters / 1,500 meters per second = 0.1 seconds.

Finally, we add the two times together to get the total time:
total_time = time_down + time_up = 0.1 seconds + 0.1 seconds = 0.2 seconds.

Therefore, it takes approximately 0.2 seconds for the dolphin to hear the echo after emitting the sound.