Chapter-15 Making Waves

1. Chapter-15Making Waves

2. Objectives • To investigate the basic nature of waves and their properties. • Wave Properties: Speed, Wavelength, Frequency, and Period. • Wave Phenomena: Reflection, Interference, and Transmission. • Waves on a string, sound waves, music, and Doppler effect.

3. Ocean Waves Wave is a traveling disturbance. Wave carries energy from place to place.

4. Types of waves

5. Transverse waves A transverse wave is one in which the disturbance is perpendicular to the direction of travel of the wave. Examples: Light wave, waves on a guitar string.

6. Longitudinal Waves Longitudinal wave is one in which the disturbance is parallel to the line of travel of the wave. Example: Sound wave in air is a longitudinal wave. Q8

7. What is a periodic wave? Periodic waves are waves that repeat.

8. Amplitude, Wavelength, and Period The amplitude, A is the maximum disturbance. The wavelength,λ  is the horizontal length of one cycle of the wave. The period, T is the time required for one complete up/down cycle of the wave.

9. Frequency and Period

10. Wave Speed E2

11. Waves on a Rope

12. Periodic Wave

13. Harmonic Wave

14. The Speed of Wave on a String

15. Guitar The strings on a steel-string guitar have different weights, µ = m/L. Q13

16. Principle of Superposition When two or more waves are present simultaneously at the same place, the resultant disturbance is the sum of the disturbances from the individual waves.

17. Constructive Interference of Sound Waves

18. Destructive Interference

19. Standing Waves

20. Nodes and Antinodes

21. What determines the frequency of a wave on a guitar string?

22. Longitudinal Standing Waves Musical instruments in the wind family depend on longitudinal standing waves in producing sound. Since wind instruments (trumpet, flute, clarinet, pipe organ, etc.) are modified tubes or columns of air, it is useful to examine the standing waves that can be set up in such tubes.

23. Standing-Wave Patterns

24. Doppler Effect