Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Homework Help: Electric field

  1. Feb 4, 2004 #1
    The electron gun in a televeision tube is used to accelerate electrons (mass of 9.10939 x 10^-31 kg and charge of -1.60218 x 10^-19 C) from rest to 2 x 10^7 m/s within a distance of .053 m. What electric field is required?
     
  2. jcsd
  3. Feb 5, 2004 #2

    ShawnD

    User Avatar
    Science Advisor

    The question only looks complicated because of the big (or small) numbers. You are given a change in velocity, a distance, and a charge.

    First find the acceleration on the electron with this equation.

    [tex]V_f^2 = V_i^2 + 2ad[/tex]

    Now find the force on the electron with this equation

    [tex]F = ma[/tex]

    Now find the electric field with this equation

    [tex]E = \frac{F}{q}[/tex]
     
    Last edited: Feb 5, 2004
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook