Waves and photons

Exercise 2

    

Calculate the frequency of electromagnetic waves at the red limit of the visible spectrum! What is the energy of the corresponding photons?

$\lambda$ $=$ $700nm$ $=$ $7\cdot 10^{-7}m$ $\nu$ $=$ $\frac{c}{\lambda}$ $=$ $\frac{3\cdot 10^8}{7\cdot 10^{-7}}$ = $4.286\cdot 10^{14}Hz$ $E_{photon}$ $=$ $h\nu$ $=$ $6.626\cdot 10^{-34}\cdot 4.286\cdot 10^{14}$ = $2.840\cdot 10^{-19} J$