1. Not finding help here? Sign up for a free 30min 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!

Electron - Vector Problem

  1. Sep 12, 2004 #1
    One part of this problem has me confused....id appreciate any guidance. I have part (a) and (b) but (c) and (d) are TOTALLY losing me. i don't even know where to begin. THANKS :smile:

    "An electron's position is given by r=3.00t i - 5.00t^2 j + 3.00 k, with t in seconds and r in meters"

    (a) In unit-vector notation, what is the electron's velocity v(t)?
    My answer: 3.00 i - 10.0t j+ 0.00 k

    (b) What is v in unit-vector notation at t=6.00s?
    My answer: 3.00 i - 60.0 j+ 0.00 k

    (c) What is the magnitude of v at t = 6.00 s? :eek:

    (d) What angle does v make with the positive direction of the x axis at t = 6.00 s? :eek:

    Thank you.
     
  2. jcsd
  3. Sep 12, 2004 #2

    Tide

    User Avatar
    Science Advisor
    Homework Helper

    To find the magnitude of a vector just square each component, add them up and find the square root.

    You can find the angle between two vectors using the "dot product:"

    [tex]\vec A \cdot \vec B = A B \cos \phi[/tex]

    where A and B are the magnitudes of the vectors and [itex]\phi[/itex] is the angle between them.
     
  4. Sep 12, 2004 #3
    thanks.... solved it :-)
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Electron - Vector Problem
  1. Electron problem (Replies: 4)

  2. Electron Problem (Replies: 4)

  3. Electron Problem (Replies: 1)

  4. Electronics Problem (Replies: 0)

Loading...