|
EXPLANATION |
|
Light has wave characteristics;
wavelength is the
peak to peak distance
of two adjacent waves.
|
03-01-02 |
| "Wavelength" |
( symbol is λ )
is equal to the "Velocity of light" divided by the frequency.
( λ = 3 * 108/ f )
The wavelength of Light is so small that it is conveniently expressed in
nanometres ( nm )
which are equal to one-billionth of a meter. Wavelength as the distance,
measured in the direction of propagation of a wave, between two successive
points in the wave that are characterized by the same phase of
oscillation. |
| "nm" (
nanometre ) |
A unit of measure often used when discussing wavelengths of Light.
µm (micrometer) is also used sometimes. |
| "Frequency" |
( symbol is f ) is equal to the "Velocity of light"
divided by the wavelength. ( f = 3 * 108/λ ) |
| "Velocity
of light" |
( symbol is c ) is approximately 300,000
kilometres per second
( about 186,000 miles per second )
( c = f * λ ) ( c as m/s ) ( f as "Hz"
) and ( λ as m ) |
| "Hz" |
Frequency is expressed in Hertz ( "Hz"
); a frequency of 1 Hz means that there is 1 cycle or oscillation per second. |
03-01-03 |
Hertz, Heinrich,
Rudolf
(German physicist)
b-1857-02-22
Hamburg Germany
d-1894-01-01
Bonn
Germany |
|
"Energy" |
The light has specific frequencies associated with the energy quanta. To remove an electron from
an atom requires several electron volts, depending on the atom. There are 2.26 x 1025 eV in one kilowatt-hour.
Visible light has a quantum energy of approximately 2 eV. |
|
"eV" |
Energy at the atomic level is commonly expressed in electron volts ( eV ) |
|
Length Conversion |
1 nm = 10-9 m = 10-6 mm = 10-3 µm
1 µm = 10-6 m = 10-3 mm = 1000 nm
|
