 # Calculate the frequency of each of the following wave lengths of electromagnetic radiation

Calculate the frequency of each of the following wave lengths of electromagnetic radiation.
1. 632.8 nm (wavelength of red light from helium-neon laser) ?
2. 503 nm (wavelength of maximum solar radiation) ?
3. 337.1 nm (wavelength of nitrogen laser) ?

c = ƒ x ?
where “c” is the speed of light in a vacuum in m/s, “ƒ” is the frequency in s^-1, and “?” is the wavelength in meters.

Part 1:

First, we must change the units of wavelength from nanometers to meters:

1 m = 10^-9 m
632.8 nm = 632.8 x 10^-9 m

c = 3.00 x 10^8 m/s
? = 632.8 x 10^-9 m
ƒ = ?

ƒ = c / ?
ƒ = (3.00 x 10^8 m/s) / (632.8 x 10^-9 m )
ƒ = 4.74 x 10^14 s^-1 or hertz

Answer: The frequency of maximum solar radiation whose wavelength is 632.8 nm is
ƒ = 4.74 x 10^14 s^-1 or hertz

Part 2:

First, we must change the units of wavelength from nanometers to meters:

1 m = 10^-9 m
503 nm = 503 x 10^-9 m = 5.03 x 10^-7 m

c = 3.00 x 10^8 m/s
? = 5.03 x 10^-7 m
ƒ = ?

ƒ = c / ?
ƒ = (3.00 x 10^8 m/s) / (5.03 x 10^-7 m)
ƒ = 5.98 x 10^14 s^-1 or hertz

Answer: The frequency of maximum solar radiation whose wavelength is 503 nm is
5.98 x 10^14 s^-1 or hertz.

Part 3
First, we must change the units of wavelength from nanometers to meters:

1 m = 10^-9 m
337.1 nm = 337.1 x 10^-9 m

c = 3.00 x 10^8 m/s
? = 337.1 x 10^-9 m
ƒ = ?

ƒ = c / ?
ƒ = (3.00 x 10^8 m/s) / (337.1 x 10^-9 m )
ƒ = 8.89 x 10^14 s^-1 or hertz

Answer: The frequency of maximum solar radiation whose wavelength is 337.1 nm is
8.89 x 10^14 s^-1 or hertz.