Answer:
λ = 5.4196 10⁻⁷m, λ = 541.96 nm this is green ligh
Explanation:
The photoelectric effect was explained by Eintein assuming that the light was made up of particles called photons and these collided with the electrons taking them out of the material.
K = h f -Ф
where K is the kinetic energy of the ejected electrons, hf is the energy of the light quanta and fi is the work function of the material.
The speed of light is related to wavelength and frequency
c = λ / f
f = c /λ
we substitute
K = h c / λ - Φ
for the case that they ask us the kinetic energy of the electons is zero (K = 0)
h c / λ = Ф
λ = h c / Ф
we calculate
λ = 6.63 10⁻³⁴ 3 10⁸ / 3.67 10⁻¹⁸
λ = 5.4196 10⁻⁷m
let's take nm
lam = 541.96 nm
this is green light
Answer:
sound vibration of spicker
Kinetic energy = 1/2 * mass in kg * speed squared
Answer:
c) True. factor four
Explanation:
The energy density of an electromagnetic wave is given by
u = ½ ε₀ E² = B² / 2μ₀
Where ε₀ is the dielectric constant and μ₀ the magnetic permittivity.
Let's apply this equation to the present case
If we double the electro field
E ’= 2 E₀
u’= ½ ε₀ (2E₀)²
u’= ½ ε₀ Eo² 4
u’= 4 u₀
Therefore the energy is multiplied by four
Let's check the answers
a) False
b) False
c) True
d) False
e) False
