Answer:
λ = 4.1638 10⁻⁷ m
Explanation:
The photoelectric effect was explained by Einstein assuming that the radiation acts like particles and the equation that describes the process is
K = h f -Ф
where K is the kinetic energy of the emitted electrons, hf the energy of the photons according to Planck's equation and Ф the work function of the material
In this case they give us the kinetic energy of the electrons
K = 0.7 eV
The sodium work function is tabulated Ф = 2.28 eV
Let's find the frequency of the photons
f = (K + Ф) / h
Planck's constant is
h = 6.626 10⁻³⁴ J s (1 eV / 1.6 10⁻¹⁹ J) = 4.136 10⁻¹⁵ eV s
f = (0.7 + 2.28) / 4.136 10⁻¹⁵
f = 7.2050 10¹⁴ Hz
let's find the wavelength using the relationship between speed and frequency and wavelength
c = λ f
λ = c / f
λ = 3 10⁸ / 7.205 10¹⁴
λ = 4.1638 10⁻⁷ m
<span>25,000 miles per hour
hope that this helps</span>
Answer:
Explanation:
It is given that,
The planet Mercury travels in an elliptical orbit with eccentricity 0.206, e = 0.206
The minimum distance from the sun,
The relation between the minimum and the maximum distance from the sun is given by :
a is the maximum distance from the sun
or
So, the maximum distance from the sun is . Hence, this is the required solution.
Answer:
Yes, dimensionally the equation is correct.
Explanation:
This equation is the kinematic equation for uniformly accelerated motion, then we study the units of each member to conclude whether it is dimensionally correct.
vi = initial velocity [m/s]
a = acceleration [m/s^2]
t = time [s]
v = final velocity
therefore we have:
[m/s] + [m/s^2]*[t^2], the second term now is m/s
[m/s] + [m/s] = [m/s]
So the analysis is correct.
Distance/time=speed
1500/18=83
=83 m/s