Where am I going wrong with this problem?

  1. The four 1.0 g spheres shown in the figure are released simultaneously and allowed to move away from each other.


    Here's my attempt at a solution. All sphere's have same charge and are situated in a square.

    [​IMG]

    Thanks.
     
  2. jcsd
  3. berkeman

    Staff: Mentor

    I'm assuming you are asked for the final velocity of each of the masses with respect to the stationary frame of reference. One error I see, 1g does not equal 0.0001kg. The rest of your approach looks reasonable.
     
  4. Thanks, corrected the mass (silly me) and recalculated. Computer still doesn't like this answer???

    [​IMG]

    Any ideas?
     
  5. berkeman

    Staff: Mentor

    I'm getting a different exponent on the potential energy terms. Maybe check your units in each of the equations to be sure you are using mks throughout. (Of course I may be calculating the potential energies wrong as well.)
     
  6. My goodness it is questions like these that make me so angry. Just got an email back from my Prof he said I need to think about all the pairs in the problem. So I needed to take into account all six pairs in the problem (1 on 2, 1 on 3, 1 on 4, 2 on 3, 2 on 4, and 3 on 4).

    Got the answer correct now thanks for all your help.
     
Know someone interested in this topic? Share this thead via email, Google+, Twitter, or Facebook

Have something to add?