I think it is 100 dB .I holp it is help.
Answer:
<h2><em>
12.45eV</em></h2>
Explanation:
Before calculating the work function, we must know the formula for calculating the kinetic energy of an electron. The kinetic energy of an electron is the taken as the difference between incident photon energy and work function of a metal.
Mathematically, KE = hf - Ф where;
h is the Planck constant
f is the frequency = c/λ
c is the speed of light
λ is the wavelength
Ф is the work function
The formula will become KE = hc/λ - Ф. Making the work function the subject of the formula we have;
Ф = hc/λ - KE
Ф = hc/λ - 1/2mv²
Given parameters
c = 3*10⁸m/s
λ = 97*10⁻⁹m
velocity of the electron v = 3.48*10⁵m/s
h = 6.62607015 × 10⁻³⁴
m is the mass of the electron = 9.10938356 × 10⁻³¹kg
Substituting the given parameters into the formula Ф = hc/λ - 1/2mv²
Ф = 6.63 × 10⁻³⁴*3*10⁸/97*10⁻⁹ - 1/2*9.11*10⁻³¹(3.48*10⁵)²
Ф = 0.205*10⁻¹⁷ - 4.555*10⁻³¹*12.1104*10¹⁰
Ф = 0.205*10⁻¹⁷ - 55.163*10⁻²¹
Ф = 0.205*10⁻¹⁷ - 0.0055.163*10⁻¹⁷
Ф = 0.1995*10⁻¹⁷Joules
Since 1eV = 1.60218*10⁻¹⁹J
x = 0.1995*10⁻¹⁷Joules
cross multiply
x = 0.1995*10⁻¹⁷/1.60218*10⁻¹⁹
x = 0.1245*10²
x = 12.45eV
<em>Hence the work function of the metal in eV is 12.45eV</em>
The cross section is the little tiny circle you see when you cut a wire
and look at the flat, cut end.
The cross-sectional area of the wire is the area of that little circle.
It's equal to
Area = (pi) x (1/4) x (Diameter of the wire)²
here's your correct answer.. please copy it..
Answer:
T = 13.17 N
the correct one is there is a digested centripetal acceleration towards upward
Explanation:
For this exercise we can use Newton's second law at the bottom of the pendulum's path
we will assume that the upward direction is positive
T - W = m a
in this case it is describing a circle the acceleration is central
a = v² / R
where the radius of the trajectories equals the length of the pendulum
R = L
we substitute
T = mg + m v² / L
T = m (g + v² / L)
When reviewing the different statements, the correct one is there is a digested centripetal acceleration towards upward
let's calculate the tension of the rope
T = 1 (9.8 + 1.6 2 / 0.760)
T = 13.17 N
