WAVE PROPERTIES

Wave Nomenclature Crest, Trough, Node and Antinode – The crest is the highest part of the wave – The trough is the lowest part of the wave – A node is the place with the least disturbance – An antinode is the place with the most disturbance Crests and troughs are antinodes Amplitude – The distance from the center to the crest crest trough node antinode amplitude

Wave Nomenclature (continued) Wavelength (symbol, SI Unit meters) – The length of one complete wave – The distance (in meters) between crests or between troughs – Graphically, you must be looking at amplitude vs. position Period (symbol T, SI Unit meters) – The time it takes to complete one wave – The time(in seconds) between crests or between troughs – Graphically, you must be looking at amplitude vs. time wavelength d (m) period t (s)

Wave Nomenclature (continued) Frequency (symbol f, SI Unit Hertz) – Frequency is the number of complete waves per second – Since period is the number of seconds per complete wave, period and frequency are reciprocals –, where f is frequency and T is period Phase – The fraction of a wavelength that a wave has traveled – We usually refer to the fraction of a wavelength compared with a sine wave – In writing equations, phase is often written in degrees phase is 0 d (m) phase is ¼ of a wavelength phase is ½ of a wavelength phase is 1 wavelength d (m) phase is ¼ of a wavelength phase is ½ of a wavelength phase is 1 wavelength

Types and Kinds of Waves Transverse or longitudinal – Transverse: The disturbance is perpendicular to the motion – Longitudinal: The disturbance is parallel to the motion Mechanical or Electromagnetic – Mechanical Waves require a physical material in which to travel Sound, water waves and waves in a string are mechanical – Electromagnetic Waves do not require a physical material Light, radio, radar, infrared, ultraviolet, x-rays and  –rays are electromagnetic

Types and Kinds of Waves (continued) Pulse or Continuous – Pulse: A single back-and-forth motion – Continuous: A continuous back-and-forth motion Traveling or Standing – Traveling: A wave with nodes and antinodes that change their position – Standing: A wave with nodes and antinodes that remain in one position Click on the link below to see an animation of standing and traveling waves – Standing and traveling waves Standing and traveling waves

Amplitude Perpendicular to Displacement Click on the image on the right to play the video clip. Note the direction of the disturbance in the slinky and the direction that the disturbance travels along the length of the slinky. What it the name of this type of a wave? In order to run this clip in slow motion or frame-by-frame, double click on the file Amp perp motion 1.wmv in the Wave Properties folder and select Full Mode from the View menu (Ctrl 1). Then adjust the Play Speed Settings or use the button arrows below the play speed bar.

Amplitude Parallel to Displacement Click on the image on the right to play the video clip. Note the direction of the disturbance in the slinky and the direction that the disturbance travels along the length of the slinky. What it the name of this type of a wave? In order to run this clip in slow motion or frame-by-frame, double click on the file Amp par motion 2.wmv in the Wave Properties folder and select Full Mode from the View menu (Ctrl 1). Then adjust the Play Speed Settings or use the button arrows below the play speed bar.

Amplitude vs. Speed of Wave Click on the image on the right to play the video clip. Note the amplitude of the wave and the speed of the wave. Does the amplitude affect the speed? In order to run this clip in slow motion or frame-by-frame, double click on the file Amp vs speed 3.wmv in the Wave Properties folder and select Full Mode from the View menu (Ctrl 1). Then adjust the Play Speed Settings or use the button arrows below the play speed bar.

Frequency vs. Speed Click on the image on the right to play the video clip. Note the frequency of the wave and the speed of the wave. Does the frequency affect the speed? Does the frequency affect the wavelength? In order to run this clip in slow motion or frame-by-frame, double click on the file Amp vs freq 4.wmv in the Wave Properties folder and select Full Mode from the View menu (Ctrl 1). Then adjust the Play Speed Settings or use the button arrows below the play speed bar.

Reflection Click on the image on the right to play the video clip. Each person produces a wave pulse. When the pulses meet, do they reflect off each other or pass through each other? In order to run this clip in slow motion or frame-by-frame, double click on the file Reflection 5.wmv in the Wave Properties folder and select Full Mode from the View menu (Ctrl 1). Then adjust the Play Speed Settings or use the button arrows below the play speed bar.

Interference When the two pulses meet the amplitude where the pulses overlap changes. How does it change? (The bottom video is a magnified view of where the pulses overlap.) In order to run these clips in slow motion or frame-by-frame, double click on the files Interference 6.wmv or Interference Zoomed 7.wmv in the Wave Properties folder and select Full Mode from the View menu (Ctrl 1). Then adjust the Play Speed Settings or use the button arrows below the play speed bar.

Reflection from a Fixed (Rigid) Boundary The wave that comes from the left is an incident wave. When the incident wave reflects off the student on the right and comes back it is a reflected wave. The student on the right is holding the end of the slinky so that it is fixed in place (rigid). Is the reflected wave upright (comes back on the same side as it went down on) or is the reflected wave inverted (comes back on the opposite side it went down on) when it reflects from a rigid boundary? In order to run this clip in slow motion or frame-by-frame, double click on the file Side pulse returns on 8.wmv in the Wave Properties folder and select Full Mode from the View menu (Ctrl 1). Then adjust the Play Speed Settings or use the button arrows below the play speed bar.

Reflection from a Free (Non-Rigid) Boundary The wave that comes from the left is an incident wave. When the incident wave reflects off the string and comes back it is a reflected wave. The part of the wave that keeps moving through the string is a transmitted wave. The string tied to the end of the slinky makes that end free (non-rigid) because the string can move perpendicular to the wave. Is the reflected wave upright (comes back on the same side as it went down on) or is the reflected wave inverted (comes back on the opposite side it went down on) when it reflects from a non-rigid boundary? In order to run this clip in slow motion or frame-by-frame, double click on the file Reflection from less rigid boundary 9.wmv in the Wave Properties folder and select Full Mode from the View menu (Ctrl 1). Then adjust the Play Speed Settings or use the button arrows below the play speed bar.

Reflection Going from More Dense to Less Dense Medium The incident wave is in the snaky (more dense). The reflection is from a less dense medium (the slinky). Is the reflected wave upright (comes back on the same side as it went down on) or is the reflected wave inverted (comes back on the opposite side it went down on) when it reflects from a less dense medium? In order to run this clip in slow motion or frame-by-frame, double click on the file Snaky to slinky 10.wmv in the Wave Properties folder and select Full Mode from the View menu (Ctrl 1). Then adjust the Play Speed Settings or use the button arrows below the play speed bar.

Reflection Going from More-Dense to Less-Dense Medium The incident wave is in the slinky (less dense). The reflection is from a more dense medium (the snaky). Is the reflected wave upright (comes back on the same side as it went down on) or is the reflected wave inverted (comes back on the opposite side it went down on) when it reflects from a more dense medium? In order to run this clip in slow motion or frame-by-frame, double click on the file Slinky to snaky 11.wmv in the Wave Properties folder and select Full Mode from the View menu (Ctrl 1). Then adjust the Play Speed Settings or use the button arrows below the play speed bar.

Transmission from Slinky to Snaky The incident wave is in the slinky (less dense). The transmitted wave is in the snaky (more dense medium). Is the transmitted wave upright (continues on the same side as it went down on) or is the transmitted wave inverted (continues on the opposite side it went down on) when it mores from a less dense medium into a more dense medium? In order to run this clip in slow motion or frame-by-frame, double click on the file Transmission-SlinkyToSnaky 12.wmv in the Wave Properties folder and select Full Mode from the View menu (Ctrl 1). Then adjust the Play Speed Settings or use the button arrows below the play speed bar.

Transmission from Snaky to Slinky The incident wave is in the snaky (more dense). The transmitted wave is in the slinky (less dense medium). Is the transmitted wave upright (continues on the same side as it went down on) or is the transmitted wave inverted (continues on the opposite side it went down on) when it mores from a more dense medium into a less dense medium? In order to run this clip in slow motion or frame-by-frame, double click on the file Transmision-SnkayToSlinky 13.wmv in the Wave Properties folder and select Full Mode from the View menu (Ctrl 1). Then adjust the Play Speed Settings or use the button arrows below the play speed bar.

Speed vs. Density of Medium The slinky is the less dense medium and the snaky is the more dense medium. In which medium does the wave travel the fastest? In order to run this clip in slow motion or frame-by-frame, double click on the file Speed 14.wmv in the Wave Properties folder and select Full Mode from the View menu (Ctrl 1). Then adjust the Play Speed Settings or use the button arrows below the play speed bar.

Wavelength vs. Medium The slinky is the less dense medium and the snaky is the more dense medium. In which medium does the wave travel the fastest? How does the wavelength in the more dense medium compare with the wavelength in the less dense medium? In order to run this clip in slow motion or frame-by-frame, double click on the file Wavelength 15.wmv in the Wave Properties folder and select Full Mode from the View menu (Ctrl 1). Then adjust the Play Speed Settings or use the button arrows below the play speed bar.