Compute an order-of-magnitude estimate for the frequency of an electromagnetic wave with wavelength equal to the following.

+1 vote

Compute an order-of-magnitude estimate for the frequency of an electromagnetic wave with wavelength equal to the following

 

(a) your height

10^-13

10^-9

10^4

10^8

10^10

10^12

How is this wave classified on the electromagnetic spectrum?

 

(b) the thickness of a sheet of paper (≈ 6.00*10-5 m)

10^-13

10^-9

10^4

10^8

10^10

10^12

How is this wave classified on the electromagnetic spectrum?

asked Mar 27, 2012 in Physics by awesome ~Expert~ (1,479 points)
edited Mar 27, 2012 by awesome
    

1 Answer

+2 votes
 
Best answer

The wavelength and frequency of electromagnetic waves are related by:

wavelength = speed of light / frequency

therefore frequency is :

frequency = speed of light / wavelength

speed of light = 3*10^8 m/s

 

and so for part A, assuming your height is about 1.7 m, you would substitute that in for wavelength and solve for frequency and get a number of magnitude 10^8, which is a radio wave.

 

Similarilily for part B:

frequency = speed of light / wavelength

frequency =  3*10^8 m/s / 6*10^-5 m 

so the answer is roughly of magnitude 10^12 , which is an infrared wave

answered Mar 27, 2012 by pokemonmaster ~Expert~ (3,856 points)
selected Apr 1, 2012 by awesome

Related questions




...