Recent content by andrew410

  1. A

    Need help with nonlinear differential equations

    The problem is on competing species. For the problem, I am supposed to find the critical points. For each critical point, I need to find the eigenvalues and eigenvectors and classify the type of critical point and its stability. dx/dt = x(1.5 - x - 0.5y) dy/dt = y(2 - y -0.75x) I got...
  2. A

    Question about relativistic energy

    A pion at rest (m_pi = 273m_e) decays to a muon (mass = 207m_e and an antineutrino (mass = 0). Find the kinetic energy of the muon and the energy of the antineutrino in electron volts. How am I supposed to start this problem? ANy help would be great...thx!
  3. A

    Need help with Lorentz Transformation equations

    where in the text am I given that xr = xb? EDIT: I found where it says xr = xb in the text. It says "Both flashes are observed to occur at the same place in S'." I just missed that...
  4. A

    Need help with Lorentz Transformation equations

    A red light flashes at position xr = 3.00 m and time tr = 1.00*10^-9s, and a blue light flashes at xb = 5.00 m and tb = 9.00*10^-9s, all measured in the S reference frame. Reference frame S' has its origin at the same point as S at t = t' = 0; frame S' moves uniformly to the right. Both...
  5. A

    Understanding the Relativistic Doppler Effect for Police Radar Technology

    One applies the doppler shift to find the shift in frequency because of time dilation. Not sure how many doppler shifts occur though...1?
  6. A

    Understanding the Relativistic Doppler Effect for Police Radar Technology

    More specifically the problem deals with the relativistic doppler effect. Police radar detects the speed of a car. Microwaves of a precisely known frequency are broadcast toward the car. The moving car reflects the microwaves with a Doppler shift. The reflected waves are received and...
  7. A

    Solve for Integral of √(25+x²) with Help | Calc Problem Assistance

    I need to get the integral for sqrt(25+x^2). I can't seem to get the answer without a arcsinh. Can anyone help me? Thx in advance! :)
  8. A

    Problem with electromagnetic waves

    Lasers have been used to suspend spherical glass beads in the Earth's gravitational field. a) A black bead has a mass of 1 micrograms and a density of 0.200 g/cm^3. Determine the radiation intensity needed to support the bead. b) If the beam has a radius of 0.200 cm, what is the power...
  9. A

    Need help on another electromagnetic problem

    A uniform circular disk of mass 27.0 g and radius 37.0 cm hangs vertically from a fixed, frictionless, horizontal hinge at a point on its circumference. A horizontal beam of electromagnetic radiation with intensity is incident on the disk in a direction perpendicular to its surface. The disk is...
  10. A

    How Do Microwaves Affect Water Temperature in Different Sized Containers?

    Let us model the electromagnetic wave in a microwave oven as a plane traveling wave moving to the left, with an intensity of 26.6 kW/m^2. An oven contains two cubical containers of small mass, each full of water. One has an edge length of 6.40 cm and the other, 12.8 cm. Energy falls...
  11. A

    Transformers for Efficient Power Transmission | Calculating Line Loss

    A transmission line that has a resistance per unit length of 4.5*10^-4 ohms/m is to be used to transmit 5 MW over 400 miles (6.44*10^5 m). The output voltage of the generator is 4.5 kV. a) What is the line loss if a transformer is used to step up the voltage to 500 kV? b) What fraction of the...
  12. A

    Maximizing Power Efficiency: Solving for Power Factor in RL Circuit

    Suppose you manage a factory that uses many electric motors. The motors create a large inductive load to the electric power line, as well as a resistive load. The electric company builds an extra-heavy distribution line to supply you with a component of current that is 90 degrees out of phase...
  13. A

    Question about RLC circuits

    A person is working near the secondary of a transformer, as shown in the figure below. The primary voltage is 120 V at 60.0 Hz. The capacitance C, which is the stray capacitance between the hand and the secondary winding, is 10.0 pF. Assuming that the person has a body resistance to ground R...
  14. A

    Magnetic field of a coaxial cable

    The figure below is a cross-sectional view of a coaxial cable. The center conductor is surrounded by a rubber layer, which is surrounded by an outer conductor, which is surrounded by another rubber layer. In a particular application, the current in the inner conductor is 1.86 A out of the page...
Back
Top