The wavelengths of light emitted by a firefly span the visible spectrum but have maximum intensity near 550 nm. a typical flash lasts for 100 ms and has a power of 1.2 mw. if we assume that all of the light is emitted at the peak-intensity wavelength of 550 nm, how many photons are emitted in one flash?

Explanation:

First of all, let's calculate the energy of a single photon of wavelength

which is given by

The power of the flash is

and the time it lasts is

so the total energy delivered in one flash is

This energy contains exactly N photons each of energy , so the number of photons emitted in one flash is

what type of charge does it have? negative