(some) Types of Waves:

Transcription

1 Waves hapter 25

2 (some) Types of Waves: Ocean waves Earth Quakes (ground vibrations) Sound Waves Light Waves Radio Waves Sonic Boom Microwave X Ray Infra Red waves RADAR SONAR Ultraviolet Waves Gamma Rays Alpha Waves (brain waves) Heat Waves EKG (electrocardiogram) Ultra sound

3 I would suggest you take notes like this: WAVES Wave: a wiggle/disturbance in space and time NOTE: When energy is transferred by a wave from a vibrating source to a receiver, there is no transfer of matter between the two points. Parts of the Transverse/Sine wave: 1 wavelength 1 wavelength 1 wavelength Period: WAVES The time necessary for one full wave to pass. Measured in seconds (s). frequency = # of waves in a certain time frequency = cycles/second = frequency is measured in s 1 s 1 = hertz frequency is measure in hertz (Hz) frequency = 1 1 period = T period = 1 frequency = Longitudinal Waves: Instead of moving up and down, the wave moves forward and backward along the direction of the wave. s 1 f High parts of the wave are called CRESTS λ = Wavelength: Low parts of the wave are called TROUGHS linear distance along the wave needed to complete one wave cycle. Measured in meters (m). The dark bars correspond to COMPRESSIONS. They are analogous to transverse 'CRESTS' The light bars correspond to RAREFACTIONS. They are analogous to transverse 'TROUGHS' Longitudinal Wave: the pulse causes a disturbance in the direction of the wave. Amplitude: distance from the midpoint to the crest or trough of the wave. Measured in meters (m). Transverse Wave: (1) (2) the pulse causes a disturbance perpendicular to the direction of the wave.

4 Wave: A wiggle/disturbance in space and time

5 Let's generate some waves: If you strike the node, the node won't vibrate.

6 Transverse/Sine: WAVES CAN GO... Up... Down... Up... Down... OR... Now side to side, and we have a wave!

7 We can do better!!!

8 Transverse Slinky Waves:

9 NOTE: When energy is transferred by a wave from a vibrating source to a receiver, there is no transfer of matter between the two points. In English: The wave moves around the room, but you wind up back in your seat (the same place you started!)

10 Parts of the Transverse/Sine wave: High parts of the wave are called CRESTS Low parts of the wave are called TROUGHS

11 Parts of the Transverse/Sine wave: λ = Wavelength: linear distance along the wave needed to complete one wave cycle. Measured in meters (m).

12 Parts of the Transverse/Sine wave: λ = Wavelength: linear distance along the wave needed to complete one wave cycle. Measured in meters (m).

13 Wavelength can also be measure from any point along the wave, as long as a cycle is completed. 1 wavelength λ = Wavelength: linear distance along the wave needed to complete one wave cycle. Measured in meters (m).

14 Wavelength can also be measure from any point along the wave, as long as a cycle is completed. 1 wavelength 1 wavelength 1 wavelength λ = Wavelength: linear distance along the wave needed to complete one wave cycle. Measured in meters (m).

15 Amplitude: A distance from the midpoint to the crest or trough of the wave. Measured in meters (m).

16 Period: T The time necessary for one full wave to pass. Measured in seconds (s).

17 The back and forth oscillations of a wave is referred to as Simple Harmonic Motion Just like the pendulum of a clock moving back and forth with time.

18 Moving a pendulum linearly while it is oscillating makes... A TRANSVERSE Wave!!

19 Look at how the frequencies of each of these pendulums are different. 1.0s The longer the pendulum, the longer the period of oscillation. 2.0s

20 frequency = # of waves in a certain time frequency = cycles/second = s frequency is measured in s 1 s 1 = hertz Watch the slinky to help you see!!! frequency is measure in hertz Hz

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22 101,000,000 wavelengths ( ) hit your radio's antenna each second!!!

23 Your cell phone works the same way. Every phone number corresponds to a unique radio frequency.

24 frequency = 1 = 1 period T period = 1 = 1 frequency f

25 Longitudinal Wave:

26 Longitudinal Wave:

27 Longitudinal Wave:

28 Longitudinal Wave:

29 Longitudinal Wave:

30 Longitudinal Wave:

31 Longitudinal Wave:

32 Longitudinal Wave:

33 Longitudinal Wave:

34 Longitudinal Wave:

35 Once again its Slinky Time

36 Longitudinal Waves: Instead of moving up and down, the wave moves forward and backward along the direction of the wave. Wavelength This is how sound waves work, but that's next chapter!!!

37 Longitudinal (This is how you draw them) vs. Transverse

38 Longitudinal (This is how you will see them) vs. Transverse

39 Longitudinal vs. Transverse COMPRESSIONS The dark bars correspond to COMPRESSIONS. They are analogous to transverse 'CRESTS'

40 Longitudinal vs. Transverse The dark bars correspond to COMPRESSIONS. They are analogous to transverse 'CRESTS' The light bars correspond to RAREFACTIONS. They are analogous to transverse 'TROUGHS'

41 Longitudinal vs. Transverse The dark bars correspond to COMPRESSIONS. They are analogous to transverse 'CRESTS' The light bars correspond to RAREFACTIONS. They are analogous to transverse 'TROUGHS'

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43 Longitudinal Wave: the pulse causes a disturbance in the direction of the wave. Transverse Wave: the pulse causes a disturbance perpendicular to the direction of the wave.

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45 Wave Properties Review Please grabba:

46 Which wave has the greatest frequency? A. B. 1 D B A C 1. C. D.

47 Which wave has the greatest amplitude? A. B. D 2 A B C 2. C. D.

48 Which wave has the greatest wavelength? A. B. D A 3 C B 3. C. D.

49 Which wave has the lowest frequency? A. B. 4 C B D A 4. C. D.

50 ANSWERS:

51 Which wave has the greatest frequency? A. B. 1. C. D.

52 Which wave has the greatest amplitude? A. B. 2. C. D.

53 Which wave has the greatest wavelength? A. B. 3. C. D.

54 Which wave has the lowest frequency? A. B. 4. C. D.