Question

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.)
Henry
d = V*t
2*76.5 = 1500t
Solve for t.