physics

posted by .

An electron and a proton are initially very far apart (effectively an infinite distance apart). They are then brought together to form a hydrogen atom, in which the electron orbits the proton at an average distance of 5.11 10-11m. What is EPEfinal - EPEinitial, which is the change in the electric potential energy?

  • physics -

    They attract, so the potential energy will go down as they get close. (the result will be negative)
    the force is a constant *1/r^2 = k/r^2
    (You can do the charges and Coulomb's law)
    So the real question is what is the integral from r = infinity to r = R (which is given as 5.11*10^-11) of 1/r^2 dr ?

    int from infinity to R of dr/r^2 = -1/r at R - (-1/r) at infinity

    = -1/R
    now use that with k Q1 Q2 /r^2
    to get
    - k (charge of electron)^2 / R
    for the change in potential energy coming in from infinity.
    Of course that loss of potential went somewhere, so the thing must have that amount of kinetic energy, which is probably the next problem.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. AP PHYSICS

    An electron and a proton are initially very far apart (effectively an infinite distance apart). They are then brought together to form a hydrogen atom, in which the electron orbits the proton at an average distance of 5.29*10^.11m. …
  2. physics

    an electron and a proton are initially very far apart (effectively an infinite distance apart.) they are then brought together to form a hydrogen atom, in which the electron orbits the proton at an average distance of 5.29 x 10 -11 …
  3. physics

    A proton and an electron in a hydrogen atom are separated by a distance of 5.3 x 10-11 m. The magnitude and direction of electric field set up by the proton at the position of the electron is: a. 5.1 x1011 N/C away from the proton …
  4. physics

    An electron and a proton have charges of an equal magnitude but opposite sign of 1.6 10-19 C. If the electron and proton in a hydrogen atom are separated by a distance of 5.4 10-11 m, what are the magnitude and direction of the electrostatic …
  5. physics

    An electron and a proton are initially very far apart (effectively an infinite distance apart). They are then brought together to form a hydrogen atom, in which the electron orbits the proton at an average distance of 5.40 10-11 m. …
  6. Physics

    Two particles with charges +8e and -8e are initially very far apart (effectively an infinite distance apart). They are then fixed at positions that are 7.07 x 10-12 m apart. What is EPEfinal - EPEinitial, which is the change in the …
  7. Physics

    A hydrogen atom is at the earth's surface. The electron and proton in the atom are separated by a distance of 5.29x10^-11m. What is the ratio of the magnitude of the electrical force exerted by the proton on the electron to the weight …
  8. physics

    In the Bohr model of the hydrogen atom, an electon mass= 9.11 x 10^-31 kg orbits a proton at a radius of 5.29 x 10^-11 m. The proton pulls on the electron with a force of 8.20 x 10^-8N. what is the speed of the electron?
  9. Physics

    In the hydrogen atom, the distance between the electron and the proton is 5x10^-11m. a)Compute the magnitude of the gravitational force FG between the electron and the proton b)Compute the magnitude of the electrical force FE between …
  10. physics

    An electron and a proton have charges of opposite sign, but the magnitude of their charges has the same value of 1.60 10-19 C. Suppose the electron and proton in a hydrogen atom are separated by a distance of 4.30 10-11 m. What are …

More Similar Questions