Final answer:
The best summary of the relationship between time and distance in echolocation and sonar is that the farther away the detected object, the longer it takes for the returning sound waves to return, since the speed of sound is constant in a given medium.
Step-by-step explanation:
Understanding Echolocation and Sonar Relationship
The relationship between time and distance in echolocation and sonar is pivotal for navigation and ranging. The correct statement that summarizes this relationship is: The farther away the detected object, the longer it takes for the sound waves to return. Since the speed of sound is constant within the same medium, the time delay between emitting a sound and receiving its echo directly correlates with the distance. The greater the distance, the longer the time taken for the sound to travel to the object and reflect back to the source.
For instance, when a bat or a dolphin uses echolocation, the time for the echo to return is directly proportional to the distance from the object. Similarly, ships employing sonar for undersea exploration use the time lapse between sending and receiving sound waves to calculate the depth of the ocean below.
The amplitude of sound waves decreases with distance, but this is not because the speed decreases; rather, it is due to the spreading out of the wave's energy. Therefore, the returning sound waves do not travel slower or faster based on the distance of the object; they simply take more time to return when the object is farther away.