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!

Is this easy charge problem correct?

  1. Jan 25, 2009 #1
    1. The problem statement, all variables and given/known data
    -----------------------------------------
    A charge of -1.0 µC is located at the origin, a second charge of 2.6 µC is located at x = 0, y = 0.1 m, and a third charge of 13 µC is located at x = 0.2 m, y = 0. Find the forces that act on each of the three charges.
    I need to find the y forces on the charge 2.6 µC. I have one last try.

    2. Relevant equations
    -----------------------------------------
    F=k*((q1)(q2)/r2)
    K = 9E9 Nm2/c2
    q1= charge 1 in columbs
    q2 = charge 2 in columbs
    r = distance between the two charges (in meters)

    a2 + b2 = c2
    sin(xº)=O/H

    #1E#2 = #1*10^#2

    3. The attempt at a solution
    -----------------------------------------
    F1 = 9E9 * ((2.6µC)*( -1.0µC))/.12
    F1 = -2.34 N
    *It's negative because its being pulled down due to attraction

    F2 = 9E9 * ((2.6µC)*( 13.0µC))/.2242
    F2 = 5.6 N
    **.1m2 +.2m2 =.05 , .05.5 = .224m **
    **.1m and hyptonuse angle: sin-1(.2m/.224) = 63.23º **
    ** Other angle is 26.76º (90º-63.23º)**
    sin(xº)=O/H --> H*sin(xº)=O
    5.6 N sin (26.76º) = +2.54 N

    +2.54 N - 2.34 N = +.2 N
    Is this the correct answer? +.2N
    ------------------------------------
    I tried using 5.6cos(26.56º) = 5.009N (Hcos(xº) = A) for the x forces and it told me I was wrong. I plugged in 5 N & -5 N :|
     
    Last edited: Jan 25, 2009
  2. jcsd
  3. Jan 25, 2009 #2

    Delphi51

    User Avatar
    Homework Helper

    The physics looks good. I didn't check the calculator work, except for the angle - and I got 26.56 degrees instead of your 26.76 degrees. Better check that again. Use tan instead of sin so you don't get any rounding error due to the hypotenuse calc.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Is this easy charge problem correct?
  1. Easy Problem (Replies: 10)

  2. Easy problem (Replies: 1)

  3. Easy problem (Replies: 13)

Loading...