How Do You Calculate Photon Flux on a Surface?

AI Thread Summary
To calculate the photon flux hitting a 2 sq. meter surface illuminated with a power of 10 W/m^2 at a wavelength of 600 nm, the intensity is already provided, eliminating the need to derive it from the source power. The energy of each photon can be determined using the equation E=hc/λ, where h is Planck's constant and c is the speed of light. Given that the total energy hitting the surface per second is 20 Joules (10 W/m^2 multiplied by 2 sq. meters), the number of photons can be calculated by dividing this energy by the energy per photon. This results in a straightforward calculation of the photon flux based on the known intensity and wavelength. The final answer provides the photon flux impacting the surface.
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Homework Statement


An area of 2 sq. meter is lit with power 10W/m^2 with light on wave length equal to 600nm.
What is the photon flux that HIT the 2 sq. meter surface.


Homework Equations


E=hv - plank const and frequency (c/lambda)
Photon flux of EMITTED source is flux=N/t=P/hv


The Attempt at a Solution


It seems, that somehow the emitted flux P/hv has to be connected with flux that hit the surface...
 
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It seems that the question is stated in terms of the intensity of light on the surface (a constant 10W/(m^2) - note that this is INTENSITY, not power). In this case there is no need to calculate the intensity of light falling on the surface from the power of the source - it is given in the question. In that case, it is simply a matter of finding the number of photons in the 20 Joules that reach the surface each second from the Planck's constant relation given, E=hc/l.
 
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