Suppose a dolphin sends out a series of clicks that are reflected back from the bottom of the ocean 65 m below. how much time elapses before the dolphin hears the echoes of the clicks? (the speed of sound in seawater is approximately 1530 m/s.)

To solve this problem it is necessary to apply the concepts related to the kinematic equations of motion.

By definition we know that speed can be expressed as

Where,

t = time

d = distance

For this specific case we know that the speed traveled corresponds to the round trip, therefore

Re-arrange to find t (The time taken to here the echo)

Replacing with our values we have that the distance is equal to 65m

Therefore the time before the dolphin hears the echoes of the clicks is 0.085s