Question

A solar flare produced 1.6 × 10^12 J of light energy. Assuming monochromatic photons of wavelength 562 nm, (bright yellow light) how many photons were in the flare?

Answer 1

energy associated with wavelength of 562 nm

energy = hc/$\lambda$

where h = $6.6*10^{-34}$ Js

c= $3* 10^8 m/s$

and $\lambda = 562*10^{-9}$ m

substituting these values in formula for energy we get; E=$3.53*10^{-19}$ J

no. of photons = $1.6*10^{12} / 3.53*10^{-19}$

no. of photons= $4.5*10^{30}$