Question

Motivating experiments

Answer 1

Answer:

a) Φ = 4.97 eV, b) the Planck model, it assumes that the frequencies are discrete and therefore it raises a discrete expression for the energi

           E = h f

c)    p / A = 7.66 10⁶  W / m²

Explanation:

a) the photoelectric effect was described by Einstein, assuming the existence of light quanta, which is why it is described by the equation

              h f = K + Ф

in this case the speed of light is

             c = λ f

             h c / λ = K + Φ

if we assume that the scientific energy of the electrocutors is zero

           hc / λ = fi

           Φ = 6.63 10⁻³⁴  3 10⁸/250 10⁻⁹

           Φ = 7,956 10⁻¹⁹ J

reduced to eV

         Φ = 7,956 10⁻¹⁹ (1 ev / 1.6 10⁻¹⁹ J)

          Φ = 4.97 eV

b) in the Rayleigh-Jean model the quantities are all continuous, but does not explain phenomenon at high energy

In the Planck model, it assumes that the frequencies are discrete and therefore it raises a discrete expression for the energi

           E = h f

temperature is a continuous variable in both models

c) the power emitted by a black body is given

            P = σ A e T⁴

             

for a black body, emicivity is one

           P / A = σ T⁴

let's use Wien's law of displacement to find the temperature

            λ T = 2,898 10⁻³

            T = 2,898 10⁻³ / λ

             T = 2,898 10⁻³ / 850 10⁻⁹

             T = 3,409 10³ K

we calculate

          P / A = 5,670 10⁻⁸ 3409⁴

          p / A = 7.66 10⁶  W / m²

d) The Bohr model is slightly modified to include the atoms with an electron

             En = - k e2 / 2 ao (Z2 / n2)

             r = n2 ao / Z