Quantum Physics: Calculating Photons/s

AI Thread Summary
An incandescent light bulb consuming 75 W emits only 5% of its energy as visible light at a wavelength of 597 nm, corresponding to a frequency of 5.02e+14 Hz. The energy per photon is calculated using the equation E = hf, resulting in approximately 3.3297e-19 J/photon. The total power output in visible light is 3.75 W (5% of 75 W), which translates to 3.75 J/s. Dividing this by the energy per photon gives approximately 2.252e20 photons/s. The initial error was corrected by factoring in the 5% efficiency of the bulb.
TJDF
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Homework Statement



I have another question,
An incandescent light bulb consuming 75 W emits only 5% of this energy as visible light of wavelength 597 nm; the frequency of the emitted light is 5.02e+14 Hz. How many photons per second of this light does the bulb emit?

Homework Equations



E = hf

The Attempt at a Solution



E = (6.626068e-34)x(5.02513e14 Hz)= 3.3297e-28 J/photon

75 W = 75 J/s

(75 J/s)/(3.3297e-28 J/photon) = 2.252e29 photon/s

but... I'm wrong... I don't know why.
 
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oops... 3.3297e-28 is actually 3.3297e-19...

but that gives me 2.252e20 photons/s, which is still marked as incorrect, am I still missing something?
 
oops, forgot the 5%, got it now.
 
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