Very simple problem about wavelength, just a double check on work

  • Thread starter Thread starter vande060
  • Start date Start date
  • Tags Tags
    Wavelength Work
AI Thread Summary
The discussion revolves around calculating the wavelength and frequency of radiation given a wavenumber of 1200 cm^-1. The correct wavelength is determined to be approximately 8.33 x 10^-6 meters, and the corresponding frequency is calculated as 3.6 x 10^13 Hz. Participants confirm the calculations, noting that the definition of wavenumber can vary, but the provided solution is accurate under the assumption that wavenumber is defined as 1/λ. Clarifications about the context of wavenumber are discussed, emphasizing the importance of definitions in physics calculations. The final consensus is that the calculations are correct based on the given definitions.
vande060
Messages
180
Reaction score
0

Homework Statement



radiation with a frequency of 1200cm^-1, calculate the wavelength in meters and the frequency in hertz



Homework Equations



wavenumber = 1/λ

freq = c/λ



The Attempt at a Solution



1200cm^-1 = 1/λ

λ = 8.33*10^-6 m

freq = (3.0 * 10^8)/(8.66*10^-6) = 3.6*10^13 Hz
 
Physics news on Phys.org
vande060 said:

Homework Statement



radiation with a frequency of 1200cm^-1, calculate the wavelength in meters and the frequency in hertz

Homework Equations



wavenumber = 1/λ

freq = c/λ

The Attempt at a Solution



1200cm^-1 = 1/λ

λ = 8.33*10^-6 m

freq = (3.0 * 10^8)/(8.66*10^-6) = 3.6*10^13 Hz
Hi vande060.

Looks good to me, & I'm a spectroscopist.

(I assume that's 1200 cm-1 in a vacuum.)
 
vande060 said:

Homework Statement



radiation with a frequency of 1200cm^-1, calculate the wavelength in meters and the frequency in hertz
Do you mean wavenumber?

Homework Equations



wavenumber = 1/λ

freq = c/λ



The Attempt at a Solution



1200cm^-1 = 1/λ

λ = 8.33*10^-6 m

freq = (3.0 * 10^8)/(8.66*10^-6) = 3.6*10^13 Hz
I think that's right. :approve: But realize that depending on the context, wavenumber sometimes is defined as 1/λ and sometimes defined as 2π/λ. The above looks right to me assuming that you are using the wavenumber = 1/λ definition, and assuming that you mean the wavenumber is 1200 cm-1.
 
Thanks, both of you
 
vande060 said:

radiation with a frequency of 1200cm^-1

if its wave number, then your answer is correct?
 
TL;DR Summary: I came across this question from a Sri Lankan A-level textbook. Question - An ice cube with a length of 10 cm is immersed in water at 0 °C. An observer observes the ice cube from the water, and it seems to be 7.75 cm long. If the refractive index of water is 4/3, find the height of the ice cube immersed in the water. I could not understand how the apparent height of the ice cube in the water depends on the height of the ice cube immersed in the water. Does anyone have an...
Thread 'Variable mass system : water sprayed into a moving container'
Starting with the mass considerations #m(t)# is mass of water #M_{c}# mass of container and #M(t)# mass of total system $$M(t) = M_{C} + m(t)$$ $$\Rightarrow \frac{dM(t)}{dt} = \frac{dm(t)}{dt}$$ $$P_i = Mv + u \, dm$$ $$P_f = (M + dm)(v + dv)$$ $$\Delta P = M \, dv + (v - u) \, dm$$ $$F = \frac{dP}{dt} = M \frac{dv}{dt} + (v - u) \frac{dm}{dt}$$ $$F = u \frac{dm}{dt} = \rho A u^2$$ from conservation of momentum , the cannon recoils with the same force which it applies. $$\quad \frac{dm}{dt}...

Similar threads

Replies
4
Views
2K
Replies
6
Views
4K
Replies
5
Views
8K
Replies
3
Views
10K
Replies
2
Views
2K
Replies
1
Views
2K
Replies
3
Views
2K
Back
Top