Question $3$

$1$ pts

Light is shining perpendicularly on the surface of the earth with an intensity of $691\frac{W}{m^2}.$ Assuming that all the photons in the light have the same wavelength $($in vacuum$)$ of $722$ nm $,$ determine the number of photons per second per square meter that reach the earth.

Enter your answer in scientific notation.

If your answer is $5\mathrm{.}14{10}^4,$ input $5\mathrm{.}14e+4$ as your answer.