Dolphins of the open ocean are classified as Type II Odontocetes (toothed whales). These animals use ultrasonic "clicks" with a frequency of 54.9 kHz to navigate and find prey. Suppose a dolphin sends out a series of clicks that are reflected back from the bottom of the ocean 76.5 m below. How much time elapses before the dolphin hears the echoes of the clicks? (Assume that the speed of sound in seawater is 1500 m/s.)

d = V*t

2*76.5 = 1500t
Solve for t.

To solve this problem, we can use the formula:

Time = Distance / Speed

First, let's calculate the time it takes for the sound to reach the bottom of the ocean.

Distance = 76.5 m
Speed of sound in seawater = 1500 m/s

Time to reach the bottom = Distance / Speed
Time to reach the bottom = 76.5 m / 1500 m/s

Calculating this:

Time to reach the bottom = 0.051 seconds

Next, we need to calculate the time it takes for the sound to return to the dolphin.

Since the sound needs to travel the same distance back, the total distance will be twice the distance to the bottom.

Total distance = 2 * Distance
Total distance = 2 * 76.5 m

Calculating this:

Total distance = 153 m

Now we can calculate the total time it takes for the dolphin to hear the echoes:

Time = Total distance / Speed
Time = 153 m / 1500 m/s

Calculating this:

Time = 0.102 seconds

Therefore, the dolphin will hear the echoes of the clicks approximately 0.102 seconds after sending them out.