Respuesta :
Answer:
The kinetic energies are 0.46 eV and 0.78 eV.
Explanation:
Given that,
Work function = 1.5 eV
Wavelength = 632.8 nm
We need to calculate the energy for red helium neon laser
Using formula of energy
[tex]E=\dfrac{hc}{\lambda}[/tex]
Put the value into the formula
[tex]E=\dfrac{4.136\times10^{-15}\times3\times10^{8}}{632.8\times10^{-9}}[/tex]
[tex]E=1.96\ eV[/tex]
We need to calculate the kinetic energy
Using formula of K.E
[tex]K.E=E-\phi[/tex]
[tex]\phi[/tex]=work function
E = energy
Put the value into the formula
[tex]K.E=1.96-1.5[/tex]
[tex]K.E=0.46\ eV[/tex]
We need to calculate the energy for green helium neon laser
Using formula of energy
[tex]E=\dfrac{4.136\times10^{-15}\times3\times10^{8}}{543.5\times10^{-9}}[/tex]
[tex]E=2.28\ eV[/tex]
We need to calculate the kinetic energy
Using formula of K.E
[tex]K.E=2.28-1.5[/tex]
[tex]K.E=0.78\ eV[/tex]
Hence, The kinetic energies are 0.46 eV and 0.78 eV.
