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  1. Dopplershift

    Other Entering a PhD Physics Program While Teaching High School?

    Hello, I am currently a high school physics teacher in Chicago. I am thinking about going back to school to get a PHD in Physics. I currently have a B.S. in Applied Physics and a secondary education license. I would like to find a way to go back and get a PHD. I cannot afford to quit my job...
  2. Dopplershift

    I Understanding Continuous Variable QKD

    So, I am doing my undergraduate research project in Quantum Cryptography, and I have some confusion in a few areas, especially in the topic of continuous variable quantum key distribution. From what I understand, Discrete Variable - Single photon. That is, for example, the BB84 protocol. Bob...
  3. Dopplershift

    Rocket's Initial Mass

    The problem states: Typical chemical fuels yield exhaust speeds of the order of 103 m/s. Let us imagine we had a fuel that gives v0 = 3 × 105 m/s. What initial mass of fuel would the rocket need in order to attain a final velocity of 0.1c for a final mass of 1 ton? I derived the equation in the...
  4. Dopplershift

    Find Hamiltonian given Force

    Homework Statement A particle with mass, m, is subject to an attractive force. \begin{equation} \vec{F}(r,t) = \hat{e}_r \frac{k}{r^2}e^{-\beta t} \end{equation} Find the Hamitonian of the particle Homework Equations H = T + U Where T is the kinetic energy and U is the potential...
  5. Dopplershift

    Limits of Integration of a Triangle

    Homework Statement Suppose you have a Triangle with the vertices, (0,0) (1,1) and (0,1). Integrating along that path. I have some differential function dZ where Z = Z(x,y) Homework Equations The Attempt at a Solution [/B] If I need to integrate, then I need to find the limits of...
  6. Dopplershift

    Need Help With Gradient (Spherical Coordinates)

    Homework Statement Find te gradient of the following function f(r) = rcos(##\theta##) in spherical coordinates. Homework Equations \begin{equation} \nabla f = \frac{\partial f}{\partial r} \hat{r} + (\frac{1}{r}) \frac{\partial f}{\partial \theta} \hat{\theta} + \frac{1}{rsin\theta}...
  7. Dopplershift

    3-D Dirac Delta Function

    Homework Statement \begin{equation} \int_V (r^2 - \vec{2r} \cdot \vec{r}') \ \delta^3(\vec{r} - \vec{r}') d\tau \end{equation} where: \begin{equation} \vec{r}' = 3\hat{x} + 2\hat{y} + \hat{z} \end{equation} Where d $\tau$ is the volume element, and V is a solid sphere with radius 4, centered...
  8. Dopplershift

    I Schrodinger's Interpretation of the Wave Function?

    Schrodinger developed his famous wave equation which describes how the quantum state of a system changes over time. But, what was Schrodinger trying to initially prove with his equation?I assume that it has to do with Debrogile's hypothesis. I know from my classes that we use the Schrodinger...
  9. Dopplershift

    I Train Thought Experiment

    Hey all, I was re-reading my quantum mechanics books and I noticed that different books have different scenarios for the Einstein Train thought experiment. And I was just wondering if I understood it correctly. Scenario 1: A person inside a moving train flashes a light beam that goes in...
  10. Dopplershift

    Partial Differentiation Laplace Equation Question

    Homework Statement Consider the Laplace Equation of a semi-infinite strip such that 0<x< π and y>0, with the following boundary conditions: \begin{equation} \frac{\partial u}{\partial x} (0, y) = \frac{\partial u}{\partial x} (0,\pi) = 0 \end{equation} \begin{equation} u(x,0) = cos(x)...
  11. Dopplershift

    Teaching With the Game Portal

    So I have found this awesome resource called 'Teaching with Portal" For those who do not know, Portal is a puzzle game where players have to solve challenges given certain components in the environment that they are in. Somebody has created a "Teaching with Portal" lesson plans (found here)...
  12. Dopplershift

    Other How can I prepare myself not to fail again?

    So I failed a physics class for the first time ever, I just finished my junior year of college, and I unfortunately failed my Electricity and Magnetism class and will have to take it next spring which means that I have a semester to prepare myself to retake it. The class is the junior level E&M...
  13. Dopplershift

    I Determining the Rate at Which Functions approach Infinity

    With basic fractions, the limits of 1/x as x approaches infinity or zero is easily determine: For example, \begin{equation} \lim_{x\to\infty} \frac{1}{x} = 0 \end{equation} \begin{equation} \lim_{x\to 0} \frac{1}{x} = \infty \end{equation} But, we with a operation like ##\frac{f(x)}{g(x)}##...
  14. Dopplershift

    Divergence problem

    So I have this problem which wants me to find the divergence of: \begin{equation} \vec{B}(x,y,z) = (x^3+y^2z)\hat{x}+(y^3+x^2z)\hat{y} \end{equation} Given that the divergence is given by: \begin{equation} \nabla \cdot \vec{B} = (\hat{x}\frac{\partial}{\partial x}+...
  15. Dopplershift

    What do physics teachers do in the summer?

    As I am considering becoming a high school physics teacher, I am wondering what physics teachers do for work in the summer? Do you work in labs, or do you do jobs unrelated to physics? Thanks!
  16. Dopplershift

    PhD in Physics Education

    I've been reading recently that there is a new branch of physics offered in graduate school with an emphasis on physics education, and is something I am considering doing. I'm also working on getting my teaching license to teach high school. But the thing is that I really want to get a Ph.D...
  17. Dopplershift

    Are length and time Trade-offs in relativity?

    In special relativity, When an object travels at speeds near the speed of light, time slows down for the person on traveling at that speed, thus you gain more time. Also, you have length contraction. So my question is this, with the idea of 4-dimesional space-time, is what you gain in time...
  18. Dopplershift

    LaTeX Is Latex still relevant?

    As a current Physics student, I am wondering if LaTex is still worth learning? How often is LaTex still used, and do you think WYSIWYG editors like Microsoft Word has replaced the need to learn LaTex? I appreciate your opinions. Thanks
  19. Dopplershift

    Why do people use a centrifugal force

    So I was doing a research paper on the differences of gravity at various places on the Earth, and I found a few sites and videos that tried to explain that a centrifugal force caused by the Earth's rotation was a cause for the disparity in gravitational acceleration at various places on the...
  20. Dopplershift

    Would the Earth Have A Delay Reaction if the Sun disappeared

    So, I heard the other day from someone online who claimed that if the sun would to suddenly disappear that the Earth would still travel in its regular path for 8 minutes before breaking off. The person claimed that because it takes light 8 minutes to reach Earth, and that since nothing can...
  21. Dopplershift

    Becoming a Physics Teacher

    So I decided that I want to be a teacher (maybe high school and possibly college). To those who are physics teachers / professors, I would like to know what advice you can give me as well as what you like about being a teacher, and what you dislike? Thanks. :)