From the nature of light unit

Ryan B

1. The problem statement, all variables and given/known data

Q: An electromagnetic radiation has a frequency of 5.00 x 10^14 Hz.
a) Calculate its wavelength in a vacuum, in meters and nanometers.
b) Calculate its wavelength in water.
c) Is this radiation visible? If so, what is its colour?
d) What is the index of refraction of a medium in which the speed of this radiation
is 2.54 x 10^8 m/s?
e) Where would you encounter this radiation in your daily life?

I just need help with e)




2. Relevant equations

3. The attempt at a solution

10. An electromagnetic radiation has a frequency of 5.00 x 1014 Hz.

a) Calculate its wavelength in a vacuum, in meters and nanometers.

Given: The speed of light in a vacuum is 3.00 x 108 m/s.

Required: the wavelength of electromagnetic radiation, that has a frequency of 5.00 x 1014 Hz, in a vacuum, in meters and nanometers.

Analysis: c=(f)(wavelength{vac}) and c=(n)(wavelength{med})
Therefore wavelength(vac) = (n)(wavelength{med}) and wavelength(med) = wavelength(vac)/n

Solution: λ = (3.00 x 108 m/s) / (5.00 x 1014 Hz)
Λ = 6.00 x 10-7 m or 600nm

b) Calculate its wavelength in water.

Given: wavelength = 0.6 x 10^-6m or 600nm
n = 1.33 for water

Required: wavelength(med)

Analysis: c=(f)(wavelength{vac}) and c=(n)(wavelength{med})
therefore wavelength(vac) = (n)(wavelength{med}) and
wavelength(med) = wavelength(vac)/n

Solution: wavelength(med) = (0.6 x 10^-6m)/1.33
= 4.51 x 10^-7 or 451 nm

Phrase: The wavelength in water of an electromagnetic radiation, that has a frequency of 5.00 x 1014 Hz, is 451 nm

c) Is the radiation visible? If so, what is its colour?

Yes, the radiation is visible as orange (in a vacuum), since orange has a range of 590nm to 610nm on the spectrum and violet (in water), since violet has a range of 400nm – 450nm.

d) What is the index of refraction of a medium in which the speed of this radiation is 2.54 x 108 m/s?

Given:
Speed of light: 3.00 x 108 m/s
Speed of radiation in the medium: 2.54 x 108 m/s

Required: the index of refraction.

Analysys: n = speed of light in a vacuum/speed of light in a medium

Solution: n = (3.00 x 108 m/s)/(2.54 x 108 m/s)
n = 1.18

e) Where would you encounter this radiation in your daily life?

The only searches that come back to me are bronze....HELP!

rock.freak667

Search for the electromagnetic spectrum and see what the frequency/wavelength corresponds to.

Ryan B

I think it's between tv/fm radios and microwaves/radar? Am I wrong?

Ryan B

was i wrong when i said bronze?

rock.freak667

Where does it lie now?

Ryan B

In the visible light spectrum

rock.freak667

then you'd encounter it as light from where?

Ryan B

Hydrogen gas, neon gas, sodium or mercury vapour?

rock.freak667

....or from the sun...sunlight.