In the diagram, sonar is used to locate a sunken ship. If the sonar echo is heard after 3 seconds, how long did it take for the signal to reach the sunken ship? Why?

1.5s

Explanation:

Given parameters:

Time taken for the echo to be heard  = 3s

Unknown:

Time taken for signal to reach the ship = ?

Solution:

An echo is phenomenon that originates from wave reflection.

If the travel time of the echo is 3s, the time it takes the echo to reach the ship is half of this time.

 So,

   Time taken to reach the sunken ship =   = 1.5s

magnitude and direction

double the distance = divide strength by 4