Net Force of a charged particle (Coulomb's Law)

AI Thread Summary
The discussion revolves around a homework problem related to the net force on a charged particle using Coulomb's Law. The original poster is frustrated with their calculations, which do not match the expected results of 0.17 N and -0.046 N. Participants point out potential errors, such as miscalculating the distance and incorrectly using charge values. Clarifications are made regarding the proper use of variables in calculations, specifically the radius and charge values. Overall, the conversation highlights common mistakes in physics problems and the importance of careful attention to detail.
Saladsamurai
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Homework Statement


I really can't see where I am going wrong here. I would latex out my work, but it would take way too long, so I have scanned it in. It should be easy enough to read though.

Its NUMBER 7, fig 21-22 Also the blurr says '100 nC'
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The Attempt at a Solution


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crapass...
 
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.The solution says .17 N and -.046 N but clearly mine arent even close. I have redone the problem twice and keep getting the same components
 
This is killing me! This should be simple vector addition, nothing more. I'm going to go smash something. . .
 
Well, I think the you got the -.046 thing correct, and the other answer looks to be .67... so i think its a typo error.

Neways, what did you smash?:wink:
 
Why did you put 0.025 in your denominator? I don't understand why you have it as 0.5a^2. a = 0.05 m. So that is the distance between Q3 and Q4 and Q3 and Q1.

I got the same answers as the book did.
 
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hage567 said:
Why did you put 0.025 in your denominator? I don't understand by you have it as 0.5a^2. a = 0.05 m. So that is the distance between Q3 and Q4 and Q3 and Q1.

I got the same answers as the book did.

I am such a douchebag sometimes. Ya know. I see the variable r and I automatically this radius of circle and I cut it in half. Thanks hage.
 
lol, it happens. You're welcome.
 
I looks like you are making some silly mistakes. E.g. i) (5cm)^2=(0.05m)^2=0.0025m^2. Why are you using (0.025m)^2? ii) In F31 you have the charges as 100 and 100, shouldn't they be 100 and 200? Yeah, stuff like that does make me want to hit something. Usually myself. Don't do it.
 
  • #10
Dick said:
I looks like you are making some silly mistakes. E.g. i) (5cm)^2=(0.05m)^2=0.0025m^2. Why are you using (0.025m)^2? ii) In F31 you have the charges as 100 and 100, shouldn't they be 100 and 200? Yeah, stuff like that does make me want to hit something. Usually myself. Don't do it.

:puts giant rubber mallet down: oh. . . okay :(
 
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