WAVES

Wave Vocabulary Pulse: a single ripple Continuous Wave: a ripple that repeats over and over Medium: the material a wave travels through ( example: sound = air, ocean waves = water ) Light is special because it doesn’t need a medium.

Transverse Waves = A wave that transmits by moving UP and DOWN and UP and DOWN Examples: 7-Peaks Wave Pool, light, ripples on a pond Atoms move UP and DOWN but they are NOT pushed forward!

Longitudinal Waves = A wave that transmits by squeezing and stretching LEFT and RIGHT, SQUISH STRETCH SQUISH STRETCH Examples: squishing a slinky, sound

Draw a Longitudinal Wave: |||| | | | |||| | | | |||| | | | ||||

WAVES TRANSPORT ENERGY and NOT Objects!!!

Wave Anatomy

Amplitude and Wavelength the height of a wave (measured from the midline) Wavelength:  the distance between crests ( or troughs ) UNIT = meters ( light uses nanometers )

Time Period & Frequency Time Period: T the time between waves UNIT = seconds Frequency: f or  the number of waves every second UNIT = Hertz = Hz = waves per second

Velocity Velocity: v how quickly a wave crest moves forward UNIT = m/s

What makes a wave unique? Amplitude gives a wave INTENSITY. For example, BRIGHT light and LOUD sounds. Wavelength gives a wave PERSONALITY. For example, the color RED and the note B-Flat on a flute. Wave velocity. . . . . . Just gets a wave to its destination faster. For example, light travels almost a MILLION times faster than sound.

WAVE PICTURES Draw high frequency waves with low amplitude: Draw high amplitude waves with long wavelengths:   Draw low amplitude waves with a large time period: Draw high frequency waves with a long wavelength:

PATTERNS As the time period gets bigger the frequency gets smaller because more time between waves. This means that time period and frequency are inversely proportional.   As the wavelength gets bigger the frequency gets smaller because more distance between waves. This means that the wavelength and frequency are inversely proportional. As the amplitude gets bigger the frequency gets no pattern because they aren’t related. This means that the amplitude and frequency are not proportional. smaller more time between waves inversely smaller more distance between waves inversely no pattern they aren’t related not

ELECTROMAGNETIC WAVES & ENERGY Electromagnetic (EM) waves transport energy through a process called radiation. EM waves are made of fluctuating electric and magnetic fields caused by rapid electron movements.   EM wave energy comes in tiny packages called photons.

ELECTROMAGNETIC WAVES

Wavelength gives the wave “personality”

ELECTROMAGNETIC SPECTRUM

FULL SPECTRUM They ALL travel at the same speed!! Called the “Speed of Light.” Speed of light = c = 300 million meters per second.

ELECTROMAGNETIC SPECTRUM: Radio TV Micro Infrared Visible Ultraviolet X-Ray Gamma low energy low frequency long wavelength high energy high frequency short wavelength

RADIO WAVES = long range communication

TV Waves = . . . . . TV

Microwaves = resonance frequency of water

Infrared = heat we can ALMOST see

Visible Light = Humans can detect it with our eyes

Colors

Ultraviolet = humans can ALMOST see it

X-Rays = Go through muscles but not bones.

Gamma rays = Energy of nuclear explosions

VISIBLE LIGHT: low energy low frequency long wavelength high energy Red Orange Yellow Green Blue Indigo Violet low energy low frequency long wavelength high energy high frequency short wavelength

COLOR The perception of “color” happens inside of our minds. Grass does not appear “green” to all animals. Rather, “green” is how our brain lets us know that it is detecting a certain EM vibration. It is all in your head!

COLOR Red shirt – absorbs all the colors except red (red is not absorbed). Being red and emitting red is different. Emitting red would mean that the object would glow in the dark.

Black vs. White Black – see no photons White – see all photons