2. Warm Up What is a wave? Name all the parts of a wave you can think of Name all the different kinds of waves you can think of

3. Wave – a disturbance that travels through space and time, usually transmitting energy. Properties of Waves

4. Waves have several parts to them…

5. The normal is where the medium would be if there were no wave.

6. The normal is shown as a dotted line here.

7. The crest is the part of the wave that goes above the normal.

8. The trough is the part of the wave that goes below the normal.

9. Crest, Trough, Wavelength, Amplitude. Momentum

10. Crest, Trough, Wavelength, Amplitude. Momentum Crest

11. Crest, Trough, Wavelength, Amplitude. Momentum Crest Trough

12. Crest, Trough, Wavelength, Amplitude. Momentum Wavelength

13. Crest, Trough, Wavelength, Amplitude. Momentum Wavelength Amplitude

14. Properties of Waves

16. Mechanical Wave – a wave that requires a material in which to travel. Properties of Waves

17. Electromagnetic (visible light) waves, radio waves, microwaves and X-rays can travel through a vacuum like space Properties of Waves

21. 2 Types of waves: Properties of Waves

22. 2 Types of waves: Transverse Waves – a wave whose particles vibrate perpendicularly to the direction of wave motion. Properties of Waves

23. Crest Properties of Waves 2 Types of waves: Transverse Waves Trough

24. So remember… when the particles move perpendicular to the energy, you have a transverse wave.

25. 2 Types of waves: Longitudinal (Compression) Wave – a wave whose particles vibrate parallel to the direction of wave motion. Properties of Waves

26. 2 Types of waves: Longitudinal Wave Properties of Waves

27. 2 Types of waves: Longitudinal Wave Properties of Waves Compression Rarefaction

28. Longitudinal waves don’t have crests and troughs like transverse waves.

29. Instead they have areas of bunched up particles, and areas of spread apart particles.

30. The areas of bunched up particles are compressions. (look up top!)

31. The areas of spread apart particles are rarefactions. ( look on the bottom )

32. On a transverse wave, the wavelength is the distance between two crests or troughs.

35. On a longitudinal wave, wavelength is the distance between compressions or rarefactions.

36. Instead of writing “wavelength” all the time, scientists use the Greek letter lambda to represent wavelength.

37. Lambda = wavelength

38. Properties of Waves Wavelength

39. The amplitude of a transverse wave is how far from the normal the medium moves.

40. The amplitude of a longitudinal wave is the thickness of the compressions.

41. The amplitude of a wave tells us how much energy is in the wave. Larger amplitude means more energy!

42. Amplitude Properties of Waves

43. Frequency (f) – Hertz – number of complete cycles (1 crest and 1 trough) per second. (2 Hz = twice per second) Properties of Waves

44. frequency wavelength The light blue wave here has the smallest frequency. You can tell because it has the longest wavelength.

45. frequency The blue wave has the greatest frequency. You can see it has the smallest wavelength.

46. Frequency hertz (Hz). Frequency is measured in a unit called hertz (Hz).

47. Hz One Hz means that one crest passes a given point each second.

48. Period (T) – amount of time required for one complete vibration. Properties of Waves

50. 1 second

51. Frequency and Period are inversely related. High frequency = low period Low frequency = high period Properties of Waves

52. Frequency and Period are inversely related. f = 1T = 1 T f Properties of Waves

53. Wave Speed v = f λ v = velocity of wave (m/s) f = frequency (Hz) λ = wavelength (m) Properties of Waves

54. The piano string tuned to middle C vibrates at 264 Hz. Assuming the speed of sound is 343m/s, what is the wavelength of the sound? Properties of Waves

55. The piano string tuned to middle C vibrates at 264 Hz. Assuming the speed of sound is 343m/s, what is the wavelength of the sound? Properties of Waves v = f λ

56. The piano string tuned to middle C vibrates at 264 Hz. Assuming the speed of sound is 343m/s, what is the wavelength of the sound? 343 = Properties of Waves v = f λ

57. The piano string tuned to middle C vibrates at 264 Hz. Assuming the speed of sound is 343m/s, what is the wavelength of the sound? 343 = 264(λ) Properties of Waves v = f λ

58. The piano string tuned to middle C vibrates at 264 Hz. Assuming the speed of sound is 343m/s, what is the wavelength of the sound? λ = 1.3m Properties of Waves v = f λ

59. Green Light has a wavelength of 5.25x10 -7 m. If the frequency is 5.71x10 14 Hz, how fast does green light travel? Cool Down

60. Green Light has a wavelength of 5.25x10 -7 m. If the frequency is 5.71x10 14 Hz, how fast does green light travel? Momentum v = f λ

61. Green Light has a wavelength of 5.25x10 -7 m. If the frequency is 5.71x10 14 Hz, how fast does green light travel? v = (5.71x10 14 )(5.25x10 -7 ) Momentum v = f λ

62. Green Light has a wavelength of 5.25x10 -7 m. If the frequency is 5.71x10 14 Hz, how fast does green light travel? v = 299,775,000m/s 2.99x10 8 m/s Momentum v = f λ

63. Exit Slip 1.Draw a diagram of a wave and label the parts