2. Day 2

3. Unit 5: Waves

4. Periodic/Simple harmonic motion is back-and-forth motion.
Springs are one example
Spring simulation

5. Pendulums are another example of simple harmonic motion
Set up pendulum

6. When you hear the terms vibration or oscillation you should think of periodic motion.

7. Measuring periodic motion
Amplitude - max displacement
SI unit can be radians or meters
Period (T) - time it takes for one complete cycle.
SI unit is seconds

8. What is the period of the second hand on a clock?
What is the period of the minute hand on a clock?
What is the period of the hour hand on a clock?

10. https://www.youtube.com/watch?v=P-Umre5Np_0 Spray can

12. Frequency ( f ) - # of cycles per unit of time, how many waves go by per time.
SI units are Hertz (Hz) Hz = 1/s
How is frequency related to radio stations?

13. A fly flaps its wings back and forth 150 times each second
A fly flaps its wings back and forth 150 times each second. The period of the wing flapping is ____ sec.

14. Non-digital clocks (which are becoming rarer) have a second hand that rotates around in a regular and repeating fashion. The frequency of rotation of a second hand on a clock is _______ Hz.

15. What is simple harmonic motion?
Give 2 examples of simple harmonic motion.
The time it takes for one complete cycle is called __________.
If I know the frequency how do I calculate the period?
What are the SI units for frequency?

16. Gizmos – Simple Harmonic Motion Parts A

17. Day 3
Quiz 1

18. Mechanical waves

19. What is a wave?

20. What is a wave?
A disturbance or vibration that transfers energy.

21. What travels as a wave?

22. Light, sound, water, x-rays, radio waves
What travels as a wave?
Energy
Light, sound, water, x-rays, radio waves

23. Mechanical waves - when energy moves through a medium in a vibration.
A medium is a collection of interacting molecules
A wave transports energy not matter.

24. https://www.youtube.com/watch?v=RVyHkV3wIyk intro to waves

25. 3 main types of mechanical waves:

27. Parts of a wave:
Wavelength ( λ ) - the distance between 2 troughs or crests.
Speed/velocity (v) - is how fast the wave is moving.
Amplitude (a) - maximum displacement

28. Transverse waves
- Cause the medium to vibrate perpendicular to wave motion.

29. Longitudinal waves
- Cause the medium to vibrate parallel to wave motion.
- Example: Sound

31. Surface waves
- Travel on the surface of a medium (between 2 mediums)
- moves in circles
- example - ocean waves

33. Energy and Amplitude - High energy = high amplitude - Low energy = Low amplitude

34. http://www. physicsclassroom

35. The piano string tuned to middle C vibrates with a frequency of 264 Hz
The piano string tuned to middle C vibrates with a frequency of 264 Hz. Assuming the speed of sound is 343 m/s, find the wavelength of the sound waves being produced.

36. The piano string tuned to middle C vibrates with a frequency of 264 Hz
The piano string tuned to middle C vibrates with a frequency of 264 Hz. Assuming the speed of sound is 343 m/s, find the wavelength of the sound waves being produced.

37. The smallest insect that a bat can detect are the size of 1 wavelength of the sound the bat makes. What is the minimum frequency of sound waves required for the bat to detect an insect that is 0.57 cm long? Assume the speed of sound is 340 m/s.

38. The smallest insect that a bat can detect are the size of 1 wavelength of the sound the bat makes. What is the minimum frequency of sound waves required for the bat to detect an insect that is 0.57 cm long? Assume the speed of sound is 340 m/s.

39. As waves pass by a duck floating on a lake, the duck bobs up and down but remains in essentially one place. Why?

40. As waves pass by a duck floating on a lake, the duck bobs up and down but remains in essentially one place. Why?
The medium does not actually travel with the wave.

41. Speed and Medium
The wave speed in a mechanical wave is determined by the medium the wave is traveling through.
The speed is independent of frequency or amplitude.

42. What are the 3 types of mechanical waves?
What kind of wave is sound?
Wavelength?
Crest?
Trough?

43. https://www.youtube.com/watch?v=WffR6HrEqTA&t=51s wave pool

44. Behavior of waves Reflection Refraction Diffraction Interference
The Doppler effect

45. Reflection – when a wave bounces off of a surface.

46. Refraction - a change in the direction and speed of waves as they pass from one medium to another.

47. Diffraction - a change in direction of waves as they pass through an opening or around a barrier in their path.

48. Demo: Water bowl

49. Wave interference

53. https://www.youtube.com/watch?v=P_rK66GFeI4 slinky

54. If the string is vibrating at the right frequency you create a standing wave.

55. A standing wave pattern is a vibrational pattern created within a medium when the vibrational frequency of the source causes reflected waves from one end of the medium to interfere with incident waves from the source. *Physicsclassroom.com
Demo: Standing wave machine

56. Which example show constructive interference?
Which example shows destructive interference?
What are the resulting amplitudes of both examples?

57. Slinky demo
slinky

58. Simple Harmonic motion and Waves WS and Behavior of waves WS.

59. Day 4
Quiz 2

60. Sound
England
and
NC State (brick yard)

61. Sound travels as longitudinal waves

62. A sound wave is a pressure disturbance that travels through a medium by means of particle-to-particle interaction. As one particle becomes disturbed, it exerts a force on the next adjacent particle, thus disturbing that particle from rest and transporting the energy through the medium. *physicsclassroom.com

63. Like any wave, the speed of a sound wave refers to how fast the disturbance is passed from particle to particle. While frequency refers to the number of vibrations that an individual particle makes per unit of time, speed refers to the distance that the disturbance travels per unit of time.

64. Always be cautious to distinguish between the two often-confused quantities of speed (how fast...) and frequency (how often...).

65. If a sound wave were observed to travel a distance of 700 meters in 2 seconds, what is the speed of the wave? -What is the frequency?

66. The speed of sound
- Different media means different speeds
- Air v = 343 m/s (This is room temp.)
- Air v = 331 m/s (At STP standard temp. and pressure)
- Fresh water v = 1510 m/s
- Salt water v = 1550 m/s
- Aluminum v = 5000 m/s

67. Since 1982, STP is defined as a temperature of 273
Since 1982, STP is defined as a temperature of K (0 °C, 32 °F) and an absolute pressure of exactly 105 Pa. *

68. The speed of any wave depends upon the properties of the medium through which the wave is traveling.
vsolids > vliquids > vgases

69. Thunder and lightning question

70. What is the speed of sound in space?

71. Loudness - physical response to sound
Intensity of a wave's energy flowing through an area is measured in Decibels, dB
Loudness - physical response to sound
Pitch - frequency you hear, the higher the frequency the higher the pitch
Demo: tuning forks

72. Note
Frequency (Hz)
Wavelength (m) C
16.35 C#
17.32 F
21.83
Assume the speed of sound is 345 m/s

73. Human hearing range: 20 Hz to 20,000 Hz
Ultrasonic waves are higher than 20,000 Hz
Infrasonic waves are lower than 20 Hz
Dogs hearing range: 67 Hz to 45,000 Hz

75. - Examples: Nascar race, Fire truck
The Doppler effect
- A change in frequency due to motion of the source, the listener or both.
- Examples: Nascar race, Fire truck
Demo: Doppler ball

76. https://www.youtube.com/watch?v=imoxDcn2Sgo ambulance

78. https://www.youtube.com/watch?v=8WgSQlRymwE trumpet

79. - Resonance - when the frequency of the applied force sinks up with the natural frequency. This increases the amplitude
Example: Swing
Demo: wine glass

80. https://www.youtube.com/watch?v=rRZT7xO5KN4 breaking glass

81. Laser Microphones

82. What kind of wave is sound?
What is the difference between wave speed and frequency?
What measurement of sound determines the pitch?

83. After an ambulance passes you on the street will its pitch sound higher or lower?
When you increase a wave’s energy you increase the wave’s ________ (amplitude or speed)?
Can sound reflect?

84. Demo: Ruben’s tube

85. Sound WS

86. Day 5
Quiz 3

87. Gizmos – Waves

88. Day 6

89. Gizmos – Doppler effect

90. Day 7
Quiz 4

91. Open-Ended Resonance Tube Lab

92. Connections are at 12: :30

93. Day 8
Quiz 5

94. Slinky lab

95. Sonic boom - breaking the sound barrier
sonic boom intro
Sonic boom compilation

96. Bonus videos
amazing resonance experiment
Water and sound
Big bang Doppler effect joke
Ruben's tube
Resonance Bridge
Longest whip
pistol shrimp
Standing wave