(Solved): A 415nm xenon laser puts out 4.00W of power with a beam 5.10mm in diameter. The beam is point ...

A $415\mathrm{nm}$ xenon laser puts out $4.00\mathrm{W}$ of power with a beam $5.10\mathrm{mm}$ in diameter. The beam is pointed directly at a pinhole which has a diameter of $1.80\mathrm{mm}$. How many photons of light will travel through the pinhole per second? Assume that the intensity of the light is equally distributed across the whole area of the beam. number of photons per second: photons/s