Recent content by UVW

  1. U

    Is a Plain CV Format Preferred for Job Applications?

    Hi all, I'll be applying for grad schools in the fall, so I've been thinking a lot about CVs lately. I have a fancy, pretty, LaTeX CV (it's still clear and simple, of course). However, whenever I see CVs from professors' home pages, they usually look like they're done in Microsoft Word...
  2. U

    Calculating deformation energy

    Actually, this is specific enough for me already! Thanks very much to both of you!
  3. U

    Calculating deformation energy

    Hi all, I've been trying to understand how to calculate the elastic energy of a deformed object. For example, if I have a box, and I push on it and it deforms, how can I calculate this deformation energy? I don't know much about elasticity, but I have read a little about strain energy and...
  4. U

    Doing very theoretical undergrad research?

    I'm a junior in university right now, hoping to attend grad school for physics. At my school, all physics students have a senior research project, and the professor that I'm most likely going to do my project with is a string theorist. The project is very theoretical (i.e. no computers; purely...
  5. U

    Particle with horizontal velocity and vertical acceleration

    That's right. Before, you were using v = vy + axt, which doesn't make sense, since those directions are perpendicular. You'll need to take gneill's advice about what to do from there.
  6. U

    Evaluating Integrals: Additive Interval Property

    To expand on what Mark44 is saying, remember that these integrals represent areas under your curve, f(x). If you know how much area is under the curve between x = 0 and x = 7 and also know how much area is under the curve between x = 1 and x = 7, can you intuitively decide how to find the area...
  7. U

    Universal gas constant for 1 kg oxygen

    This doesn't sound like a very good problem. It seems that they have simply redefined the gas constant in terms of oxygen, but I've never known this to be a very useful thing to do at all. If that's a convention that you need to know for your courses, it'd be wise to learn, but I wouldn't...
  8. U

    Stressed about Physics Exam Help with refractive index concept

    Let's step back from the physicality for a minute (we'll come back to it), and just follow Snell's law, which xatu and I have stated earlier. Applying this to the first barrier, we get: n_1sin(30°) = n_2sin(30°)\\n_1 = n_2 And we come to the first conclusion, which you came up with...
  9. U

    Stressed about Physics Exam Help with refractive index concept

    Let's look at this with Snell's law: n_1sin(θ_1) = n_2sin(θ_2). Remember that the θs are measured with respect to the normal from the surface. With that in mind, how can you compare the n values for each of these?
  10. U

    When is work done on an object?

    Yes; as long as using Newton's second law is valid, this approach will work! Well, that depends on both your system and your reference frame (remember, reference frames matter here). If our system is the electron, and we're in a frame of reference at rest with respect to the proton, then we...
  11. U

    When is work done on an object?

    This will be true for other types of energy, too! Consider a system of a proton and an electron, and you move them away from each other. Since they're both in the system, their Coulombic force is internal to the system, so we can say that their Coulombic potential energy increases, and it...
  12. U

    Understanding Eigenvalues and Eigenvectors: A Beginner's Guide

    I think that Khan Academy does a great job explaining just that! http://www.khanacademy.org/math/linear-algebra/alternate_bases/eigen_everything/v/linear-algebra--introduction-to-eigenvalues-and-eigenvectors Also, don't forget that there's a "Math & Science Learning Materials" forum on this...
  13. U

    When is work done on an object?

    Ok, so we can solve this problem by being very strict in our definitions of work. First, let's make sure that we have a system; in this case, it's the block. Now, work is only defined for external forces. The person lifting the block is external to the system (the block), and the Earth...
  14. U

    Knowing Damping and Spring Constant Finding Time

    The equation looks great. We know from the characteristic equation that the solution is a linear combination of exponentials and sines/cosines whose values we can determine from the characteristic equation. After this, we can find the amplitude of the linear combination with the Pythagorean...
  15. U

    Phyiscs- Beats and frequency problem

    I don't think I understand the question. Could you include the problem statement for #4?
Back
Top