Question

A dolphin located in seawater at a temperature of 28°C emits a sound directed toward the bottom of the ocean 160 m below. How much time passes before it hears an echo?

Answer 1

To calculate the time it takes for the dolphin to hear an echo, we need to determine the total distance traveled by the sound wave, including the distance from the dolphin to the ocean bottom and back. We can use the speed of sound in seawater at the given temperature to perform the calculation.

The speed of sound in seawater is approximately 1500 meters per second, but it varies with temperature, salinity, and pressure. Assuming an average value of 1500 m/s, we can calculate the time as follows:

1. Calculate the time it takes for the sound wave to reach the ocean bottom: Distance = 160 meters Speed of sound = 1500 m/s Time = Distance / Speed of sound Time = 160 m / 1500 m/s

2. Double the time to account for the return journey of the sound wave: Total time = 2 * Time

Let's calculate it step by step:

Time = 160 m / 1500 m/s = 0.1067 seconds

Total time = 2 * 0.1067 seconds = 0.2134 seconds

Therefore, it would take approximately 0.2134 seconds (or about 213.4 milliseconds) for the dolphin to hear the echo after emitting the sound towards the bottom of the ocean.