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!

Homework Help: Acceleration of a Sphere with a Charge

  1. Jan 13, 2007 #1
    1. The problem statement, all variables and given/known data
    Two Charged spheres are positioned on a horizontal, frictionless insulating surface, as shown below.

    I attached the image at the bottom of the post.

    2. Relevant equations
    Coulombs Law and F=ma

    3. The attempt at a solution
    I plugged in ((8.99 x 10^9)(5.0 x 10^-7)(5.0 x 10^-7))/(1.25)^2

    Once I got the answer I used F=ma to find the acceleration which is 9.59 x 10^-2 m/s

    I believe this is the correct answer. I was wondering if one of the spheres is negative would I go about answering the question in the same way. Or would I have to factor in other things.

    Attached Files:

  2. jcsd
  3. Jan 13, 2007 #2
    It sounds like the initial acceleration would only differ in sign, same force, same mass. But theres much more to it, as you may suspect. If you release 2 oppositely charged objects, they will attract toward each other with decreasing distance and increasing force. The acceleration would increase until they collide. For 2 like charged objects, they will repel away from each other with increasing distance and decreasing force. The acceleration will decrease as the force approaches zero, and a final velocity is reached when the objects are at infinity. Because these situations deal with varying force/acceleration, its usually better to think in terms of energy.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook