1. Sound

2. 1. The ____ of a sound is how high or low we hear its frequency. pitch

3. 2. A ____ jet travels faster than sound. supersonic

4. 3. The shift in sound frequency caused by a moving sound source is called the ____. Doppler Effect

5. 5. What type of waves are sound waves? longitudinal

6. 4. What happens if a fire engine moves toward you? Does the pitch of its siren increase or decrease? Increase

7. 6. Which of the following sounds has the shortest wavelength? a. The rumble of thunder at 20 Hz b. A base guitar at 100 Hz c. A fire truck siren at 2,000 Hz d. The highest note on a piano at 5,000 Hz

8. 8. The speed of sound through air is approximately 340 m/s. What is the wavelength of a sound wave with a frequency of 680 Hz? 0.5 m

9. 7. How are the pitch and frequency of a sound related? Direct

10. 9. The range of human hearing is between 20 Hz and 20,000 Hz. If the speed of sound is 340 m/s, what is the longest wavelength you can hear? What is the shortest? 17 m and 0.017 m

11. 10. A paramedic in an ambulance does not experience the Doppler effect of the siren. Why?