Photons per second from lightbulb

  • #1
Kavorka
95
0

Homework Statement


[/B]
If 5 percent of the power of a 100 W bulb is radiated in the visible spectrum, how many visible photons are radiated per second?

Homework Equations



E=hf=hc/λ

The Attempt at a Solution



I know how to solve this, I just wanted to make sure.
I will take 5 W or J/s as the power of the visible light, and once you know the energy of the visible light's photon in Joules finding the photons/second is easy. I am wondering though if it would be better to present a range of photons per second since the visible spectrum is a range of frequencies/wavelengths, or an average. The question seems like it wants a single answer.
 
Physics news on Phys.org
  • #2
um
 
  • #3
Kavorka said:

Homework Statement


[/B]
If 5 percent of the power of a 100 W bulb is radiated in the visible spectrum, how many visible photons are radiated per second?

Homework Equations



E=hf=hc/λ

The Attempt at a Solution



I know how to solve this, I just wanted to make sure.
I will take 5 W or J/s as the power of the visible light, and once you know the energy of the visible light's photon in Joules finding the photons/second is easy. I am wondering though if it would be better to present a range of photons per second since the visible spectrum is a range of frequencies/wavelengths, or an average. The question seems like it wants a single answer.
Surely you could find a range. Then pick some reasonable answer in the middle.

You might assume white light - so an even distribution of frequencies, The energy is proportional to the frequency, so you get a nice energy distribution. Integrate over that someway.

Want to make things even more complicated? - - -
 
  • #4
Haha that's alright. I found a range as well as the average and will list those both, hopefully that is a satisfactory answer.
 
Back
Top