Question

What is the wavelength of light with 2.89 x 10-19 J of energy? (The speed of

Answer 1

Let's see

$\\ \rm\rightarrowtail E=hv$

$\\ \rm\rightarrowtail E=\dfrac{hc}{\lambda}$

• lambda is wavelength
• h is Planck constant
• c is velocity of sound in air
• E in energy

$\\ \rm\rightarrowtail \lambda=\dfrac{hc}{E}$

$\\ \rm\rightarrowtail \lambda=\dfrac{6.626\times 10^{-34}\times 3\times 10^8}{2.89\times 10^{-19}}$

$\\ \rm\rightarrowtail \lambda=6.878\times 10^{-7}m$

$\\ \rm\rightarrowtail \lambda=68.8\mu m$