Question

Things around you are emitting infrared radiation that includes the wavelength 1.30 10-5 m. What is the energy of these IR photons?

Answer 1

We have,
Wavelength of the infrared radiation $\rightarrow \lambda=1.30\times10^{-5}\ m$
Planck's constant $\rightarrow h=6.62607015\times10^{-34}\ Js$
Speed of the light $\rightarrow c=2.9\times10^{8}\ m/s$

The energy of the IR photons is given as:

$E=\frac{hc}{\lambda}$

$\therefore E=\frac{6.62607015\times10^{-34}\times2.9\times10^{8}}{1.30\times10^{-5}}$

${\color{Blue} \therefore E=1.4781\times10^{-20}\ J}$

Therefore, the energy of the IR photons is ${\color{Blue} E=1.4781\times10^{-20}\ J}$ .