Please Help with this Physics Problem!?

Question

Ive been working on this for a while and I cant seem to get the right answer:

A 100 W incandescent light bulb converts approximately 2.5% of the electrical energy supplied to it into visible light. Assume that the average wavelength of the emitted light is λ = 540 nm, and that the light is radiated uniformily in all directions.
How many photons per second, N, would enter an aperture of area A = 8 cm2 located a distance D = 5 m from the light bulb?

Ive determined that each photon has 2.3eV of energy, but I cant find the intensity

Answer 1

Sounds like a spherical geometry problem.

That aperature represents a fraction of the sphere's surface area.
Divide 8 cm^2 by the surface area of a sphere of radius 500 cm (A= 4*pi*r^2)


Conservation of energy and the assumption of spherically uniform spread says that that fraction of the energy from the bulb goes through the aperature.

You need to use common energy units. Look up converstion of watts to/from eV.

With energy through the hole and energy/photon you should be able to get photons/time through the hole.