Light as an Electromagnetic Wave Flashcards
What are the four characteristics that can be used to describe any wave?
Wavelength
Frequency Different for each wave
Amplitude
Speed the same for all EMS waves (3.00 x 108 m/s)
What is wavelength?
The distance between successive crests of the wave.
the distance that the wave travels as it completes one full cycle of up and down motion.
Describe the only light we can see
is called visible light, and has wavelengths in the range of 400 to 750 nanometers.
What is frequency?
How fast the wave oscillates.
Measured by the # of times a light wave completes a cycle of up and down motion per sec.
When a radio station identifies itself, its what?
the frequency used (i.e. 99.9 Virgin Radio uses a frequency of 99.9 MHz)
What are the units of frequency?
Hertz, Hz, “cycles per second”
(sometimes “cycle” is implied: sec-1 or s-1)
What is amplitude?
Is the height of the wave measured from the midline to its crest, or peak
The brightness, or intensity of light depends on the amplitude of the light wave.
Regardless of its wavelength, each type of EMR moves through a vacuum at what?
A constant speed (just under 3.00 x 10^8 m/s)
Nothing can go what?
faster than light - it’s the fastest thing ever (in a vacuum)
Light can be what though?
slowed down as it passes through air, water, glass, etc.
Since a light moves at a constant speed, (c), there is what?
a mathematical relationship between frequency (υ) & wavelength (λ)
The shorter the wavelength, the what?
the higher the frequency
The longer the wavelength, the what?
the lower the frequency
Frequency and wavelength are what?
inversely proportional
