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  1. E

    Velocity of an electron exam question

    An electron starts from rest 2.82 cm from the center of a uniformly charged sphere of radius 2.17 cm. If the sphere carries a total charge of 1.11×10-9 C, how fast will the electron be moving when it reaches the surface of the sphere? This is an exam question that I got wrong and I am trying...
  2. E

    Electric fields and acceleration

    Consider a long horizontal conducting wire with charge density = 5.70*10^-12 C/m. A proton (mass = 1.67*10^-27 kg) is placed and released 0.820 m above the wire. What is the magnitude of initial acceleration of the proton? My thought is: a=q*E/m and E is: 2*k*charge density/distance...
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    Cube of capacitors

    If I have a cube made out of capacitors, that's one capacitor for everyside for a total of 12 capacitors. Each capacitor is C=4.71 pF. How would I even begin to go about finding the total capacitance? :yuck:
  4. E

    Minimum Potential

    A charge of 0.883 nC is placed at the origin. Another charge of 0.347 nC is placed at x1 = 13.1 cm on the x-axis. At which point on the x-axis does this potential have a minimum? I do know a few things: A necessary condition for the potential to have a minimum is that its derivative is...
  5. E

    Deflection of electron

    An electron with a kinetic energy 5000.0 eV (1 eV = 1.602×10-19 J) is fired horizontally over a charged plate with surface charge density +2.0 μC m-2. Taking the positive direction to be upwards (away from plate), what is the vertical deflection of the electron after it has traveled a horizontal...
  6. E

    What is the magnitude of charge inside the box

    have a box that is 4.15 cm on each side. Using a probe I measure on two opposite sides of the box and find a nearly uniform, inward-oriented, perpendicular component of the field with the magnitude of 18.3 N/C. What is the magnitude of charge inside the box?
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    Net force on charges found to be zero

    I'm having trouble understanding some of these basic electrostatic priciples and my book isn't much help. I've put them in a true/false format. If I could get at few answers, it would really help me understand this. A positive point charge +q is placed at point p to the right of two...