(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

At what wavelength does a 100mW laser deliver 3.5 x 10^{17}photons in one second?

h (plancks) = 6.626x 10^^{-34}

c = 3 x 10^^{8}

2. Relevant equations

E = hf ==> E = hc / n (wavelength) ==> n = hc / E

Power = Energy / Time

3. The attempt at a solution

Energy = Power * Time ==> (100x10^-3 W)(3.5x10^17 photons)(1 second) = 3.5x10^16

n = hc / E ==> (3x10^8)(6.626x10^-34) / (3.5x10^16) = 5.65 x 10 ^-42 m

I think I calculated energy incorrectly, but I don't know any other formula I could use. Any help is appreciated..

Thanks!

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# Homework Help: Wavelength and Energy question

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