Sonar is used to find the location of an object, and active Sonar Active sonars transmit acoustic energy and detect targets by echolocation. Given these facts, what is used to find objects underwater among the following options:
- echolocation
 - a hydraulic system
 - heat energy
 - Electrical energy
 - dolphins
 - mussels
 - by indirect light
 - rays or beams


 

 echolocation        