Answer: 1.3 *10^6 Ω*m
Explanation: In order to explain this problem we have to use the following expression for the resistence:
R=L/(σ*A) where L and A are the length and teh area for the wire, respectively. σ is the conductivity of teh Nichrome.
Then, from mteh OHM law we have V=R*I so R=V/I=2/3.2=0.625 Ω
Finally we have:
σ=L/(R*A)=1.3/(0.625*1.6*10^-6)=1.3*10^6 Ω*m
The wavelength would be 2.980044314115. Reduced it would be 2.980 or just 2.98.
Answer:
Ф = 2.179 eV
Explanation:
This exercise has electrons ejected from a metal, which is why it is an exercise on the photoelectric effect, which is explained assuming the existence of energy quanta called photons that behave like particles.
E = K + Ф
the energy of the photons is given by the Planck relation
E = h f
we substitute
h f = K + Ф
Ф= hf - K
the speed of light is related to wavelength and frequency
c = λ f
f = c /λ
Φ =
let's reduce the energy to the SI system
K = 0.890 eV (1.6 10⁻¹⁹ J / 1eV) = 1.424 10⁻¹⁹ J
calculate
Ф = 6.63 10⁻³⁴ 3 10⁸/405 10⁻⁹ -1.424 10⁻¹⁹
Ф = 4.911 10⁻¹⁹ - 1.424 10⁻¹⁹
Ф = 3.4571 10⁻¹⁹ J
we reduce to eV
Ф = 3.4871 10⁻¹⁹ J (1 eV / 1.6 10⁻¹⁹ J)
Ф = 2.179 eV