Electrical Force and Coulomb's Law

AI Thread Summary
The discussion revolves around calculating the electrical force between an alpha particle and a gold nucleus using Coulomb's Law. The user initially struggles with understanding how to apply the charges, specifically whether to add the charges or multiply them by the elementary charge value. After clarification, the user correctly calculates the charges of the alpha particle (+2e) and the gold nucleus (+79e) and successfully applies Coulomb's Law. The confusion stemmed from the interpretation of the charges and their interaction. Ultimately, the user finds resolution and successfully computes the force after multiple attempts.
Trista
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I have been working on a problem and can't seem to figure out what I'm doing wrong. Here goes:

An alpha particle (charge = +2.0e) is sent at high speed toward a gold nucleus (charge = +79e). What is the electrical force acting on the alpha particle when it is 2.0 X 10^-14 m from the gold nucleus?

I figured it would be an easy plug and chug, like this:

F=k (|e|^2 / r^2) which when I looked at it I found I'm confused. the problem said that the charge = +2.0e. Does that mean I multiply 2 * 1.6X10^-19? Then, there are 2 charges. In order to get the correct 'e' do I add them together and multiply by 1.6x10^-19? I understand they are both positive, and so they repel from each other, but the alpha particle is sent at high speed toward the gold nucleus.

I can tell I'm not going to enjoy this chapter...

thank you for your help!
 
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2e= 2*1.6e-19=3.2e-19 C
79e=79*1.6e-19=1.264e-17 C
Just use Coulomb`s law.
 
:rolleyes: Thanks. I must be brain fried. I must have tried this 10 times and it wouldn't come out. But after your post it worked just fine.
 
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