# If you have lamp with 300 W power output And the average wavelength of the source is 590nm how many photons are emitted per second?

Jun 4, 2018

8.9 × 10^20 photons

#### Explanation:

Let the number of photons emitted in one second be $\text{n}$.

$\text{Power" = "Energy"/"Time}$

$\text{P" = ("nhc"/λ)/"t" = "nhc"/"λt}$

Rearrange the above equation

$\text{n" = "Ptλ"/"hc}$

$\textcolor{w h i t e}{\text{n") = ("300 Watt × 1 s" × 590 × 10^-9\ "m")/(6.626 × 10^-34\ "J s" × 3 × 10^8\ "m/s}}$

color(white)("n") = 8.9 × 10^20