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Topic: Help calculating Photons  (Read 2272 times)

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Offline T33

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Help calculating Photons
« on: November 28, 2017, 09:01:00 PM »
Ultraviolet light emits a total of 2.5x10–17 J of light at a wavelength of 9.8x10–7 m.  How many photons does this correspond to?

Would I use the equation E=hc/λ ?

I know E= 2.5x10–17 J
and wavelength= 9.8x10–7 m

but the equation i'm plugging into doesn't seem correct. Also would I need to divide by Avogadro's # to get photons?

Offline Corribus

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Re: Help calculating Photons
« Reply #1 on: November 28, 2017, 10:32:01 PM »
You seem to be confusing your energies, of which there are two you need to worry about: the total energy of the (beam of) light, and the energy of each photon. Do you know which one of these the equation you listed corresponds to?
What men are poets who can speak of Jupiter if he were like a man, but if he is an immense spinning sphere of methane and ammonia must be silent?  - Richard P. Feynman

Offline Enthalpy

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Re: Help calculating Photons
« Reply #2 on: November 29, 2017, 05:50:51 PM »
Since when is 0.98µm ultraviolet????

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