- #1
Dr. Who
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Homework Statement
Please refer to the image; problem-1. My theory is that there are two spheres 'A' and 'B', where 'A' is (partially and primarily) positively charged, and 'B' is (partially and primarily) negatively charged. The magnitude of negative charge is greater than the positive charge. After the spheres are in contact, negative charge from 'B', equal to the magnitude of positive charge on 'A', is transferred to sphere 'A' to balance it. The negative charge on sphere 'A' (due to induction) and leftover negative charge on 'B' are now responsible for repulsion between 'A' and 'B'. I think there is one more equation required concerning the composition of charges in the system, before and after the electrical contact. Please help!
Homework Equations
F = k[QA][-QB] / r2 → ①
where, (assuming )
QA is the initially excess positive charge on sphere 'A'
QB is the initially excess negative charge on sphere 'B'
F' = k[-Q`A][-QB + QA] / r2 →②
Where,
-Q`A is the net negative charge on sphere 'A'
[-QB + QA] is the net negative charge left on sphere 'B' after a negative charge equal to magnitude of QA is transferred to sphere 'A'.
The Attempt at a Solution
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Solving equation ① using given values;
3.003 x 10-12 = [QA][-QB]
Solving equation ②;
1.001 x 10-12 = [-Q`A][-QB + QA]