Harmonic Infrared Wave Propogation

[zorro]

Homework Statement

A plane harmonic infrared wave traveling through a transparent medium is given by Ex(y,t) = E_osin2(pi)[y/5*10^-7 - 3*10^-14t] where all the quantities are expressed in S.I. units. The vacuum wavelength of this wave is?

The Attempt at a Solution

I got the answer as 1000 nm but the given answer is 500 nm. I think the given answer is incorrect. Can somebody verify?

 

[Dorilian]

Homework Statement

A plane harmonic infrared wave traveling through a transparent medium is given by Ex(y,t) = E_osin2(pi)[y/5*10^-7 - 3*10^-14t] where all the quantities are expressed in S.I. units. The vacuum wavelength of this wave is?

The Attempt at a Solution

I got the answer as 1000 nm but the given answer is 500 nm. I think the given answer is incorrect. Can somebody verify?

How did you do the calculation?

 

[zorro]

Tell me which one is correct first then I will post my calculations.

 

[Dorilian]

Tell me which one is correct first then I will post my calculations.

It should not be 500 nm because that's the wavelength in the medium, so the vacumm wavelength should be different. The value of 3*10^-14 is strange (too small), so I don't know how did you get the 1000 nm.

 

[Dorilian]

Tell me which one is correct first then I will post my calculations.

You are right!. The refractive index is 2, (but nu=3*10^14, I was taking ^-14), so the wavelength in the vacuum is 1000 nm.

 

[zorro]

Thanks!

 

[Dorilian]

In addition, 500 nm is Not infrared, however 1000nm is in the near infrared.