1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

A Proton is Accelerated Through What Voltage?

  1. Oct 17, 2009 #1
    A metal target sphere of 30 cm diameter suspended out in space is given a charge of +1.00 nC. Through what voltage must a distant proton be accelerated from rest (by some sort of space weapon) if it is to arrive at the sphere at a speed of 8.2*10^4 m/s? (Neglect any gravitational effects.)

    K0= 8.99*10^9, mass of proton= 1.67*10^-27kg, qe= 1.6*10^-19
    V= (K0*Q)/R
    1/2mvf^2= qe*delta V

    First I calculated V: (8.99*10^9)(1.00*10^-9)/0.15m= 59.93V
    Then I calculated Delta V: 1/2(1.67*10^-27)(82000^2)/1.6*10^-19= 35.09V
    59.93V+35.09= 95V

    Now, this is where I am confused. The answer is not 35V or 59V or even 95V. I really can't see any other way to solve this problem. Where am I going wrong? Any help is greatly appreciated.
  2. jcsd
  3. Oct 17, 2009 #2


    User Avatar
    Homework Helper

    Probably right here:
    Write the general principle that you're using here.
  4. Oct 17, 2009 #3
    What do you mean? That is the equation for kinetic energy of the proton. I don't know the principle behind it.
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Similar Discussions: A Proton is Accelerated Through What Voltage?
  1. A proton accelerates (Replies: 2)

  2. Proton Accelerator (Replies: 1)