1. Interactions of Sound Waves Chapter 21 Sect. 3

2. What do you think just happened here?

3. Interactions of Sound Waves  Today, I can describe the interactions of sound waves by  Describing echolocation and types of echolocation technology  Describing resonance and resonance in musical instruments

4. Echolocation  the process of using reflected sound waves to find objects.  used by animals such bats, dolphins, and birds.  Animals use echolocation to tell how far away something is based on how long it takes sound waves to echo back to their ears.

5. Bats and Echolocation

6. Other types of Echolocation  Sonar, a type of echolocation, uses echoes underwater to locate objects.  Navigators on ships can avoid icebergs  Oceanographers map the ocean floor.  Navy can find submarines  Fishermen can find fish

7. How does echolocation work in dolphins?

8. Other types of Echolocation Ultrasonography is a medical procedure that uses echoes to see inside a patient’s body without performing surgery. Examples:  examine kidneys and other organs  check the development of an unborn child

9. What does an ultrasound show?

10. What is Resonance (rez-O-nunce) Resonance occurs when two objects naturally vibrate at the same frequency.  The wave (sound) produced by one of the objects causes the other object to vibrate.

11. Can musical instruments resonate?

12. Resonance and Musical Instruments Musical instruments use resonance to make sound.  By blowing air into wind instruments, the vibrations make a sound.  When a guitar is strummed, the body of the guitar resonates.

13. Resonance Experiment

14. Do you remember the Opera singer? Why do you think she was able to break the glass by just singing?

15. Resonance  As the opera singer sings and the sound get louder, the vibrations in the glass increase and the amplitude gets higher.  As the amplitude gets higher, the energy increases causing the glass to vibrate more. Over time, this can cause the glass to break (especially if it’s thin or flawed).