1) Calculate the energy, in units of Joules and eV, and
momentum, in kg*m/s and eV/c,...
1) Calculate the energy, in units of Joules and eV, and
momentum, in kg*m/s and eV/c, for a photon with wavelengths of: a)
1.5 pm, b) 120 nm, and c) 21.4 cm.
Since force is m*a, it has units of kg m/s^2 . Energy has units
of kg m^2/s^2. Thus it appears that by lazy dimensional analysis
that a force times a distance will have units of energy. This turns
out to be the formula to calculate work. Note also that kg m^2/s^2
looks like mv^2. Here if we use dimensional analysis, we would
*almost* find the formula for kinetic energy. We'd be off by a
factor of two since KE=1/2 mv^2....
1) Using M/S energy band diagrams, determine if Nickel (5.2 eV
workfunction) or Indium (4.1 eV workfunction) can be used to make a
Schottky diode on n-Si doped 3x1016/cm3
The person’s mass, m= 68.1 kg, the unknown drag coefficient is,
c , with units kg/s, and the local acceleration of gravity is g=
9.80 m/s2 . Our model for the person’s velocity vs time gave us a
linear differential equation whose analytical solution was the
following:
V(t) = g*m/c*[1-exp(-c/m*t)].
Your job is to find “c”. You need to use the MATLAB “help”
documentation to find the nonlinear curve fitting function and
syntax for how to use it. Hint you...
1. Calculate the permeability of electrons with energy of 0.1 eV
and 0.5 eV respectively when penetrating a positional energy
barrier of 1.0 eV in height and 100 pm in length by tunnel
phenomenon.
k Attachment image=[2m(V-E)]^1/2
T={1+(e^kL-e^-kL)^2/16ε(1-ε)}^-1 (ε= E/V)
2. Explain the meaning of tunneling covered in the above problem
with the wave and explain the difference between classical and
quantum mechanics based on it.
Calculate the number of joules that can be obtained from the
fissioning of 1 kg of Uranium-235 (U-235), assuming 198 MeV average
energy release per fission.
a) How much energy can be obtained from the U-235 in 1 kg of
natural uranium?
b) Calculate how much energy, in joules, can be obtained from
burning 1 kg of coal.
c) What is the total energy contained in the US resources of
coal and U-235?
a) An electron with 10.0 eV kinetic energy hits a 10.1 eV
potential energy barrier. Calculate the penetration depth.
b) A 10.0 eV proton encountering a 10.1 eV potential energy
barrier has a much smaller penetration depth than the value
calculated in (a). Why?
c) Give the classical penetration depth for a 10.0 eV particle
hitting a 10.1 eV barrier.
Data Table A
Mass of Cart (kg)
Impulse (N.s)
Velocity (m/s)
Momentum (N.s)
Change in Momentum
%
Diff.
Before
After
Before
After
0.2695
+0.351
- 0.673
+0.659
Data Table B
Mass of Cart + mass bar (kg)
Impulse (N.s)
Velocity (m/s)
Momentum (N.s)
Change in Momentum
% Diff.
Before
After
Before
After
0.4695
+0.346
-0.377
+0.372
% Difference= 2×(Change in
momentum-Impulse)(Change in
momentum+Impulse)×100=
Questions
What are possible reasons why the change in momentum is
different from the measured impulse?...
Calculate the mass defect and nuclear binding energy (in Joules
per nucleon) for C-16, a radioactive isotope of carbon with an
actual mass of 16.01470 amu. The subatomic particle masses are: e–
= 0.00055 amu, p + = 1.0073 amu, n0 = 1.0086 amu and 1 amu = 1.6605
x10–27 kg.
The energy of formtion of a vacancy in the copper crystal is
about 1 eV. Calculate the concentration of vacancies at room
temperature (300K) and just below the melting temperature,
1084oC. The atomic mass of Cu is Mat =
63.54g*mol-1 and the density at 293 K is
8.96cm-3. Neglect the change in the density which is
small.