Recent content by jamesjd

  1. J

    Undergrad Photodiodes vs LEDs: Gallium Arsenide Sensitivity

    Would a gallium arsenide photodiode be sensitive to light from a gallium phopsphide LED?
  2. J

    Finding dielectric constant when 7.5μC flows into capacitor

    thank you, are my calculations correct or am i missing something?
  3. J

    Finding dielectric constant when 7.5μC flows into capacitor

    Homework Statement A slab of dielectric is now inserted between the plates, the battery still being connected. 7.5μC of additional charge flows from one plate, through the battery and onto the other plate. What is the dielectric constant of the dielectric material?Homework Equations A 1.0μF...
  4. J

    Ampere's Law: Calculating Magnetic Field Strength

    Homework Statement Homework Equations State Amperes Law. Show that the magnetic field at a distance R from a very long straight wire carrying a current I has magnitude μ I / (2 pi R) The Attempt at a Solution I really don't know :(
  5. J

    Speed and kinetic energy of electron in Bohr model ground state

    9.11x10^031kg Mass of electron 1.6x10^-19 electron + proton?
  6. J

    Speed and kinetic energy of electron in Bohr model ground state

    F = m*(v^2/r)?
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    Speed and kinetic energy of electron in Bohr model ground state

    so how would i get the acceleration to use F = ma?
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    Speed and kinetic energy of electron in Bohr model ground state

    Homework Statement In the Bohr Model of the Hydrogen Atom, a single Electron orbits a circle round a single stationary Proton. If the radius of the electron's orbit for its lowest energy state (the "ground state") is 5.3x10^-11m, find the the constant speed, v , of the orbiting electron...
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    Calculate Horsepower for Pumping Water from 50m Depth at 10m/s Flow Rate

    2 kg/s ?
  10. J

    Calculate Horsepower for Pumping Water from 50m Depth at 10m/s Flow Rate

    Ep = mgh for one kg lifted 50 meters? Ek = 1/2 mv^2 for one kg at 10m/s?
  11. J

    Calculate Horsepower for Pumping Water from 50m Depth at 10m/s Flow Rate

    hmm it seems so simple but I'm struggling to grasp the concept. It takes 10Kg in 5 seconds then? Was any of my working correct?
  12. J

    Calculate Horsepower for Pumping Water from 50m Depth at 10m/s Flow Rate

    Is it not 10m? erm is the calculation Mass = flow rate/ time? I'm still confused
  13. J

    Calculate Horsepower for Pumping Water from 50m Depth at 10m/s Flow Rate

    Homework Statement A pump has to raise water from a depth of 50m and eject it at 10m/s. If the flow rate is 2 kg/s, what horsepower is needed. Homework Equations The Attempt at a Solution t = s/v = 5 seconds m = t/flow rate = 2.5kg E = mgh = 1250J P = E/t = 250W...
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