2. Waves Mechanical Electromagnetic Medium Transfer of … Pulse Periodic Perpendicular Parallel

3. Mechanical waves / EM waves Need medium Do not need medium

4. Wave features Crests / troughs Wavelength Frequency Period Speed Amplitude - energy

5. Wave interactions - INTERFERENCE

7. The pulses continue on

9. Destructive Interference

10. Pulses continue on

11. Reflection of a pulse: free boundary

12. Reflection of a pulse: fixed boundary

13. Standing Wave node antinode

14. Standing wave

16. General formula for the SW

17. If F=ma Then the motion of the particles in a string will depend on:

18. The speed of wave in a string Things to consider: a)How is the wave transferred? b)Does the velocity of particles change? c)What does that change depend on?

19. Sound intensity

20. Standing waves

21. Reflection

22. Sound - wave Mechanical Longitudinal Spherical

23. Human Hearing Range

24. Pitch Relates to frequency Is subjective

26. Doppler Effect

27. Sound intensity / Decibel level What is the intensity of a sound 60 dB?

28. Resonance If an external vibration matches the natural frequency of an object, the vibration will resonate and the object will start vibrating along.

29. Resonance If a force is applied in synch (in phase) with the existing vibration, the amplitude of the vibration will increase.

31. Acoustic body

32. Electric guitar

33. Decibels Each 10 fold in intensity = 10 dB What’s 1.0x10 -4 W/m 2 in dB? What’s I of 120 dB?

34. Doppler’s effect The switch of the pitch If the object is approaching, its sound appears___________________ If the object is moving away, the pitch is ____________________

35. Harmonics