It's probably very simple, but I'm not understanding the solution in the book. First, why are they using 1/2 a sphere area? I'm guessing because it says it is "radiating hemispherically" and the ground cuts the sphere in half?
Normally would you not just use equation 49.29 if it did not "radiate hemispherically?" Also, how did they get the E = (luminous flux / Area)? Equation 49.27 looks like a derivative to me. The formula they use looks like it is the integral of the illuminance.
TIA.
Normally would you not just use equation 49.29 if it did not "radiate hemispherically?" Also, how did they get the E = (luminous flux / Area)? Equation 49.27 looks like a derivative to me. The formula they use looks like it is the integral of the illuminance.
TIA.
