 Mechanical Wave – a vibratory disturbance that propagates through a medium. Examples – sound waves, seismic waves Examples – sound waves, seismic waves

 Medium – the material (matter) through which a disturbance travels.

 Electromagnetic Wave – energy waves produced by the oscillation or acceleration of an electric charge. Does not require a medium in order to travel. Examples – light, microwaves, radio waves Examples – light, microwaves, radio waves

 Longitudinal Wave – a wave in which the motion of the vibratory disturbance is parallel to the direction of propagation.

 Transverse Wave – a wave in which the motion of the vibratory disturbance is perpendicular to the direction of travel.

 Surface waves – waves which have characteristics of both transverse and longitudinal waves. Torsional - a twisting disturbance moving through a medium.

 Wave pulse – a single bump or disturbance. (1/2 wave)

 Cycle – one complete wave (vibration).

 Periodic wave – a series of pulses (waveform)

Label the following properties and their appropriate symbols on the diagram below.

Record the correct amount of each of the following properties:

List all of the possible intervals that represent ONE wavelength.

Draw a waveform having an amplitude of 2.0 m and a wavelength of 4.0 m.

 Frequency ( ƒ ) – the number of waves (cycles, complete vibrations) experienced in one second. Unit – Hertz (Hz) Unit – Hertz (Hz) * Not on Reference Table

Which wave has a higher frequency? Explain.

 Period ( T ) – the time required for one complete vibration (wave, cycle) to occur. Unit - seconds (s)Unit - seconds (s) * Not on Reference Table

 For most mechanical waves, both transverse and longitudinal, the speed depends only on… The medium through which the waves move. The medium through which the waves move.

Water Waves Sound Waves Air Waves on a Spring

v = ƒ λ

Determine which of the two springs is more dense by noticing how the pulse is reflected and transmitted after reaching the boundary.

The wave represents a transverse wave. Various locations of the wave are labeled and then grouped in pairs, as given below.

 Interference – the effect produced by two or more waves which are passing simultaneously through a region.

 Constructive Interference – waves combining to increase amplitude when their displacements are in the same direction.

 Destructive Interference – waves combining to decrease amplitude when their displacements are in opposite directions.

 The resultant displacement at any point is the algebraic sum of displacements of the individual waves.  When waves meet, their amplitudes combine.

Watch 1:28 to 2:54 then 4:00 to 4:54

 Node – point in a wave which doesn’t move at all.  Antinode – point in a wave having the largest displacement.

Determine the following for each diagram below: wavelength, number of nodes and antinodes, and frequency (for a given wave speed of 10.0 m/s).

As the frequency of the wave increases, the number of nodes also increases.

 Sound wave – a pressure variation that is transmitted through matter. v = 331 m/s

 Light – the range of frequencies of the electromagnetic spectrum that can be detected by the retina of the eye.

 Speed of Light (c) – in a vacuum, light has a constant speed of 3.00 x 10 8 meters per second Light travels slower when passing through different types of mediums. Light travels slower when passing through different types of mediums. ALL electromagnetic waves travel at 3.00 x 10 8 m/s in a vacuum ALL electromagnetic waves travel at 3.00 x 10 8 m/s in a vacuum

 Natural Frequency – the frequency with which an object oscillates in the absence of external forces

 What would happen if the opera singer sang a note at the same natural frequency as the crystal wine glass? Fast forward to 2:12 Fast forward to 15:00

 Resonance – the increase in amplitude of oscillation of an object when exposed to a periodic force or wave whose frequency is very close to the object’s natural frequency

 Angers Bridge, also called the Basse- Chaîne Bridge. Soldiers marching caused the bridge to collapse. Soldiers marching caused the bridge to collapse.

 Many of the serious vibration problems in engineering are caused by resonance. If the natural frequency of the car body is the same as the combustion frequency in the engine (at certain speeds), the body might begin to vibrate or shake roughly. If the natural frequency of the car body is the same as the combustion frequency in the engine (at certain speeds), the body might begin to vibrate or shake roughly.

 Tacoma Narrows Bridge Washington State Washington State November 1940November

 Nicola Tesla Resonance Device Resonance Device  Wheatstone Bridge H.S.

 Pokemon cartoon triggers seizures in thousands of Japanese children.

 Microwaves emit radio waves at a frequency of 2.5 GHz which is the natural frequency of water. Due to this fact, the radio waves cause liquid molecules to resonate (vibrate) and heat up.

Redshift The light of an object moving AWAY from an observer is shifted toward a longer wavelength, or toward the color red. Blueshift The light of an object moving TOWARD an observer is shifted toward a shorter wavelength, or toward the color blue.

 Diffraction – is the production of circular waves that spread out from the edge of an obstruction or slit as waves pass by. A change in the wavefront’s direction results. A change in the wavefront’s direction results.

 This is the reason why you can hear sounds around a corner, but not see the object producing the sound. Sound λ > Light λ Sound λ > Light λ

In 1801, Young developed an experiment that allowed him to  Make a precise measurement of light’s wavelength using diffraction.  Provide evidence of the wave nature of light.