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: Calculating how many surplus electrons on each sphere

  1. Jan 11, 2017 #1
    1. The problem statement, all variables and given/known data

    Two identical 9.60-g metal spheres (small enough to be treated as particles) are hung from separate 500-mm strings attached to the same nail in a ceiling. Surplus electrons are added to each sphere, and then the spheres are brought into contact with each other and released. Their equilibrium position is such that each string makes a 15.0 ∘ angle with the vertical

    How many surplus electrons are on each sphere?

    2. Relevant equations
    e= -1.602*10^(-19)

    3. The attempt at a solution

    I first began by converting all numbers to SI units

    Then I found the distance between the 2 balls (not sure)

    charge, I was not sure how to get this to use coulomb so I took the total mass .0096kg/(1.7*10^(-27))= an N

    N/2= number of electrons in each ball

    And I got lost here.

    I do not know how to find charge of objects in this scenario. All I know is they are the same charge because there are repelling
  2. jcsd
  3. Jan 11, 2017 #2


    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    Each is at 15 degrees to the vertical. Draw the diagram, and mark the forces acting.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted