1. How do submarines “see” underwater How do submarines “see” underwater?

2. Objectives By the end of the lesson you will describe how different types of SONAR is used in ocean exploration. You will also be able to use the average speed of sound in water to predict distances of objects underwater. » SC.912.N.1.6: Describe how scientific inferences are drawn from scientific observations and provide examples from the content being studied.

3. SONAR = SO und N avigation A nd R anging SONAR is the technology that is used to locate objects underwater

4. Passive Sonar What are some things scientists would be listening for?

5. Active Sonar Also called “echolocation” In what ways do humans use active sonar?

6. Human Application

8. Average speed of sound in water – 1500 m/s If a “ping” takes four seconds to return, how far away is the object? If a “ping” takes 8 seconds to return, how far away is the object? The deepest spot in the pacific ocean is the Marianas Trench. It has a maximum depth of about 10,500 meters. How long will it take an active sonar ping to descend to the bottom and return to the boat? 3000m 4500m 14 seconds 7 seconds