Physics. Speed of electron...

posted by .

An electron is released from rest at the negative plate of a parallel plate capacitor. The charge per unit area on each plate is = 1.5 x 10-7 C/m2, and the plates are separated by a distance of 1.4 x 10-2 m. How fast is the electron moving just before it reaches the positive plate?



THANK YOU for any help or hints or anything that you can give me!

  • Physics. Speed of electron... -

    I would find the voltage on the capacitor, or Electric field first. Using Gauss Law, then E= sigma/2epsilion

    Force/q= E
    Force=Eq
    force*distance=Eq*distance
    1/2 m v^2=Eq*distance
    solve for velocity v.

  • Physics. Speed of electron... -

    The E field between the plates is proportional to the charge per unit area, sigma (1.5 x 10-7 C/m2).

    E = sigma/epsilon

    where epsilon is the permittivity of free space, which you should look up.

    The kinetic energy that is given to the electrion while crossing the gap of length X is

    KE = e E X

    Set that equal to the final kinetic energy and solve for the velocity.

  • Physics. Speed of electron... -

    Dr WLS is correct, E between the plates is sigma/episilon, not sigma/2epsilon.

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. physics

    The plates of a parallel plate capacitor are separated by a distance of 1.2cm, and the electric field within the capacitor has a magnitude of 2.1x 10^6 V/m. An electron starts from rest at the negative plate and accelerates to the …
  2. College physics

    Two 2.4 cm diameter disks spaced 1.5 mm apart form a parallel-plate capacitor. The electric field between the disks is 4.3×10^5 V/m. What is the voltage across the capacitor?
  3. physics

    An electron is released from rest at the negative plate of a parallel plate capacitor. The charge per unit area on each plate is = 2.6 x 10-7 C/m2, and the plates are separated by a distance of 1.4 x 10-2 m. How fast is the electron …
  4. physics

    An electron is released from rest at the negative plate of a parallel plate capacitor and accelerates to the positive plate (see the drawing). The plates are separated by a distance of 1.3 cm, and the electric field within the capacitor …
  5. Physics

    An electron is released from rest at the negative plate of a parallel plate capacitor and accelerates to the positive plate (see the drawing). The plates are separated by a distance of 1.4 cm, and the electric field within the capacitor …
  6. College Physics

    A parallel plate capacitor is made of two 3.5 cm x 3.5 cm square plates that are separated by 1.6 x10 -5 m. The plates are charged to 4.8 nC each (positive and negative). An electron is released from rest at the surface of the negative …
  7. Physics #48

    An electron is released from rest at the negative plate of a parallel plate capacitor. The charge per unit area on each plate is σ = 1.67 10-7 C/m2, and the plate separation is 1.35 10-2 m. How fast is the electron moving just …
  8. Physics

    An electron is released from rest at the negative plate of a parallel plate capacitor. The charge per unit area on each plate is σ = 1.67 10-7 C/m2, and the plate separation is 1.35 10-2 m. How fast is the electron moving just …
  9. Physics

    The potential difference between the plates of a capacitor is 335 V. Midway between the plates, a proton and an electron are released. The electron is released from rest. The proton is projected perpendicularly toward the negative …
  10. Physics

    Two capacitor plates are equally and oppositely charged. They are separated by 1.30 cm. An electron is released from rest at the surface of the negative plate and, at the same time, a proton is released from rest at the surface of …

More Similar Questions