1. Homework Statement
Find the Lagrangian and equations of motion for a spherical pendulum
2. Homework Equations
L=T-U and Lagrange's Equation
3. The Attempt at a Solution
I found the Lagrangian to be L = 0.5*m*l2(ω2+Ω2sin2(θ)) - mgl*cos(θ) where l is the length of the rod, ω is (theta...
Hi all,
I'm starting graduate school and really need a better handle on computational physics. I'm not extremely experienced with MATLAB and haven't used Python or anything else. Does anyone know a good textbook to get me started? I looked in the textbooks links to this forum thread and the...
I am a first year graduate student in physics and am becoming familiarized with Raman spectroscopy to study structure of materials based off of their vibrational states.
In some personal study outside of this, I came across the idea of inelastic electron tunneling spectroscopy (IETS) and was...
1. Homework Statement
We have a particle of mass m moving in a plane described by the following Lagrangian:
\frac{1}{2}m((\dot{x}^2)+(\dot{y}^2)+2(\alpha)(\dot{x})(\dot{y}))-\frac{1}{2}k(x^2+y^2+(\beta)xy) for k>0 is a spring constant and \alpha and \beta are time-independent.
Find the normal...
I would like to preface this by stating that I am not very well-versed in cosmology or astrophysics, but I've been thinking: I understand the idea of parallax, both in the sense of human eyes measuring distances to nearby objects and in the sense of telescopes on earth (or in orbit) measuring...
This isn't a precise homework question, but this seemed like the most reasonable place to post. If not, please feel free to move it.
I have a large set of data points that should fit to a known equation (the Drude-Smith model for conductivity)
The equation the data should fit to is: σ(ω) =...
Before I get into my question, it is helpful to note the paper I am referring to.
"Photovoltage in nanocrystalline porous TiO2" by V. Duzhko, et al. DOI: 10.1103/PhysRevB.64.075204
In Section B. "Spectral photovoltage in well-passivated porous TiO2 layers", the authors mention that "The...
1. Homework Statement
I am working on a little project in which I analyze a video I found online and try to determine if it is real of a hoax. The video I am analyzing includes a man throwing a football off of a football stadium (at the very top) and making it into a basketball hoop at field...
1. Homework Statement
A mass m = 750 g is connected to a spring with spring constant k = 1.5 N/m. At t = 0 the mass is set into simple harmonic motion (no damping) with the initial conditions represented by the point P in the phase space diagram at the right. **(This phase space diagram has...
1. Homework Statement
Show that if m and n are integers such that 4|m2+n2, then 4|mn
2. Homework Equations
3. The Attempt at a Solution
Since 4 divides m2+n2, then we can say that m2+n2 = 4k, where k is an integer. I haven't done any mathematical proofs of any kind yet, but we were...
1. Homework Statement
The vectors that are perpendicular to (1,1,1) and (1,2,3) lie on a ____.
2. Homework Equations
3. The Attempt at a Solution
This is really straight forward, but I cannot validate the answer to myself. The textbook says that they should lie on a line, but why is...
Hi everybody,
I am currently a Junior in college studying Physics. I am planning on going to Graduate School, which obviously requires the GREs. I have looked up that the physics GRE is 12% Quantum Mechanics (as per this source here). However, how my University is set up, I will not be able to...
1. Homework Statement
Use either image charge method of separation of variables to solve:
The distance between two large, grounded parallel conducting plates is 4x. Between them, two point charges +Q and -Q are inserted and have a distance x and 3x from one of the plates. (A line connecting...
1. Homework Statement
Two point charges of equal value are placed a distance 2b from one another. In the middle, there is a grounded conducting sphere. What is the minimum radius of the sphere required to cancel out the repelling force between the two charges? (Solve using Image Charge Method)...
1. Homework Statement
This problem is very easy, but I'm not sure how best to "prove" it. This part of the question just states:
Prove that (1/z)* = 1/(z*) where z* is the complex conjugate of z.
2. Homework Equations
3. The Attempt at a Solution
So the complex conjugate of z = x + iy...
1. Homework Statement
This isn't really for homework, but I wasn't sure where else to put it. anyone wishes to move it, that is fine. I'm just getting into some research and I was tasked with reading data from a text file into MatLab and then graphing it by fitting it with exponentials. I am...
1. Homework Statement
y'' + 4y' + 4y = 0 ---- y(0) = 1, y'(0) = 5
Find the exact solution of the differential equation.
Use the exact solution and Euler's Method to compute Euler's Approximation for time t = 0 to t = 5 using a step h=0.05. Plot Euler's & Exact vs. t and plot Error vs. t. Then...
1. Homework Statement
Write down the equation of motion for the downward journey of a baseball subject to quadratic drag. Find v as a function of y and, given that the downward journey starts at ymax (given below), show that the speed when the ball returns to the ground is:
vterv0 /...
1. Homework Statement
A projectile that is subject to quadratic air resistance is thrown vertically up with initial speed v0.
(a): Write down the equation of motion for the upward motion and solve it to give v as a function of t.
(b): Show that the time to reach th top of the...
I have been learning some introductory quantum mechanics and stimulated Emission is giving me some problems conceptually.
I understand that photons can be absorbed to bump electrons up to higher energy levels and that electrons in the higher energy state spontaneously decay back to the lower...
In my theoretical mechanics class, we went over some very basic conservation laws (namely momentum) and talked about colliding masses.
Say you have 2 masses, m1 and m2. m1 is moving to the right (towards m2) with velocity v. m2 is stationary. After the two masses collide, m1 recoils with...
1. Homework Statement
I am in a calculus class where we are learning the introduction to row reduction. I have done this before in other courses, so I am familiar with the process, but I am not sure about this one. We were given:
x4 + 2x5- x6 = 2
x1 + 2x2 + x5 -x6 = 0
x1 + 2x2 + 2x3 - x5...
1. Homework Statement
Silver has a density of 10.5E3 kg/m3 and a resistivity of 1.6E-8 Ω*m at room temperature. On the basis of the classical free electron gas model, and assuming that each silver atom contributes one electron to the electron gas, calculate the average time, Tau, between...
1. Homework Statement
(a) Find the Fourier transform f(ω) of: f(x) = cos(x) between -pi/2 and pi/2
(b) Find the Fourier transform g(ω) of: g(x) = sin(x) between = -pi/2 and pi/2
(c) Without doing any integration, determine f(ω)/g(ω) and explain why it is so
2. Homework Equations...
1. Homework Statement
(f*g)(x) = integral from -pi to pi of (f(y)g(x-y))dy
f(x) = ∑cneinx
g(x) = ∑dneinx
en is defined as the Fourier Coefficients for (f*g) {the convolution} an is denoted by:
en = 1/(2pi) integral from -pi to pi of (f*g)e-inx dx
Evaluate en in terms of cn and dn...
1. Homework Statement
Find the volume of an object bounded by x2 + y2 ≤ 1, x2 + z2 ≤ 1 and y2 + z2 ≤ 1.
2. Homework Equations
3. The Attempt at a Solution
This stuff is very new to me (multiple integrals to find volume) so I am not entirely familiar with it. My first thought...
1. Homework Statement
The probability density at certain points for a particle in a box is zero. Does this imply that the particle cannot move across these points? Explain. (I found a picture online here).
2. Homework Equations
3. The Attempt at a Solution
In a particle in a...
1. Homework Statement
Find the shortest distance from the origin to the surface x=yz+10
2. Homework Equations
3. The Attempt at a Solution
So I said that my main function, f(x,y,z) = x^2 + y^2 + z^2 (the function I want to minimize)
Then I said that g(x,y,z) is my constraint...
1. Homework Statement
Does Bohr's correspondence principle apply only to quantum theory? Can you give an example of the applications of this principle to relativity theory?
2. Homework Equations
3. The Attempt at a Solution
According to my textbook, Bohr's Correspondence...
1. Homework Statement
This is a conceptual question that I am not quite sure about. In the Davisson-Germer Experiment (details here), do the electron diffraction peaks that occur only show up if the incident beam of electrons hits the crystal surface perpendicularly?
2. Homework...