Solving Basic Electricity Questions - 4q Net Charge

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The discussion revolves around a question regarding the net charge of three particles with different charges after they interact. The initial net charge is correctly calculated as 4q when all particles are touched together. However, confusion arises when calculating the final charge on particle C after it interacts separately with particles A and B. The discrepancy in answers stems from the interpretation of the problem; the book's answer assumes the particles retain their initial charge states for the second part of the question. Clarification is provided that the problem's wording could lead to misunderstanding, but the correct approach yields the expected results.
duki
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Hey everyone,

There is a question in my book that asks if three particles touch and are then separated (A- +5q, B - -q, C - 0) what is the net charge? I know the answer is 4q, but it also states the following:

Particle C touches A and is removed. Particle C then touches B and is removed. What is the final charge on C? I got 1.333... but the answer in the back of the book says 1.5. Am I doing something wrong?
 
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If you could explain how you got 1.33... we could help find where you went wrong.
 
i did net charge 4q / 3
 
The question is a little ambiguous. You are correct if the first thing you do is touch them all together, as in your question #1. However, the book's answer is correct if you start again in question #2 with the balls having their initial (different) charge states. Do the problem again with that assumption, and you'll get the correct answer.
 
ok. It works like that. I wonder why they didn't word it correctly. It's worded to do it how I did the first time...

Anyways, thanks for your help!
 

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