Recent content by MyNewPony

  1. M

    Equipartition Theorem Calculations

    Homework Statement a) Estimate the internal energy E in the high temperature (equipartition) limit for CO. b) Estimate the heat capacity Cv in the high temperature (equipartition) limit for NH3. Do not use partition functions in your calculations. Homework Equations <E> = KbT Cv = (7/2)R...
  2. M

    Sum of Normal Modes on a Vibrating String

    Homework Statement In textbooks, I often see the sum of the first two normal modes given in the equation attached (on the right). I'm wondering how they arrive at that equation based on the general formula (on the left). I tried subbing in n= 1 and 2 in the general formula, but I'm not sure...
  3. M

    Nodes on a Vibrating String

    Wavelength = (2/n)*length of string Can I get a hint on what to do next?
  4. M

    Nodes on a Vibrating String

    Prove that there are n-1 nodes on a string fixed at both ends for the nth harmonic. It is simple to show this using a diagram. [PLAIN]http://www.space-matters.info/img/nodesandmodes.jpg [Broken] However, is there a way to show this mathematically?
  5. M

    Cyclotron frequency of proton

    Homework Statement A 66.0-cm-diameter cyclotron uses a 530 V oscillating potential difference between the dees. How many revolutions does the proton make before leaving the cyclotron? Homework Equations f = (q*B)/(2*pi*m) The Attempt at a Solution I find the cyclotron frequency: f =...
  6. M

    Fusion of protons in the Sun

    I checked, and that was the correct answer! As for problem B, I'm not sure what they're asking. I found the average kinetic energy to be: 3.11x10^-16 J at 15 million K. Do I divide this by a certain number?
  7. M

    Fusion of protons in the Sun

    So: kq^2/r = (1/2)mv^2 + (1/2)mv^2 = mv^2 Solving for v: v = sqrt(kq^2/mr) = sqrt(((9x10^9)(1.6x10^-19)^2)/((1.6x10^-27)(2.4x10^-15))) = 7.6 x 10^6 m/s Now plugging that into this equation: T = (mv^2)/(3kb) I obtain a value of 2.3 x 10^9 K.
  8. M

    Fusion of protons in the Sun

    Homework Statement The sun is powered by fusion, with four protons fusing together to form a helium nucleus (two of the protons turn into neutrons) and, in the process, releasing a large amount of thermal energy. The process happens in several steps, not all at once. In one step, two protons...
  9. M

    Which of these source charges will produce a maximum possible speed?

    Homework Statement Your lab assignment is to use positive charge Q to launch a proton, starting from rest, so that it acquires the maximum possible speed. You can launch the proton from the surface of a sphere of positive charge Q and radius R, or from the center of a ring of charge Q and...
  10. M

    Conceptual Standing Wave Question

    Homework Statement If you take snapshots of a standing wave on a string, there are certain instants when the string is totally flat. What has happened to the energy of the wave at those instants? The Attempt at a Solution I'm assuming that nothing has happened to the energy. At...
  11. M

    Graph of a sinusoidal wave at a fixed position

    Ah, my bad. I jumped the gun and skipped the points in between each tick.
  12. M

    Height and Range of a projectile

    You know from this equation, Hmax= \frac{\left(v0sin\theta\right)^{2}}{2g}, that v0sin(theta) = sqrt(2Hg) So plug sqrt(2Hg) into: t = \frac{2vosin\theta}{g} to get: t = 2sqrt(2Hg)/g = 2sqrt(2H/g)
  13. M

    Graph of a sinusoidal wave at a fixed position

    Homework Statement A sound wave is described by D(y,t) = (0.02mm)sin[(8.96 rad/m)y + (3140 rad/s)t + pi/4 rad)], where y is in metres, and t is in seconds. Draw a displacement-versus-time graph D(y=1.00m,t) at y= 1.00 m from t= 0 s and t= 4 ms. Homework Equations D(y,t) = (0.02mm)sin[(8.96...
  14. M

    Graphing sound waves at the bottom of the ocean

    Homework Statement Ships measure the distance to the ocean bottom with sonar. A pulse of sound waves is aimed at the ocean bottom, then sensitive microphones listen for the echo. The graph shows the delay time as a function of the ship's position as it crosses 60 km of ocean. Draw a...
Top