Physics problem involving tension and electric fields

AI Thread Summary
Two small spheres, each with a mass of 4.00 g and opposite charges, are suspended by strings in a uniform electric field. The problem involves determining the electric field required for the spheres to be in equilibrium at a 15.0° angle. There is confusion regarding the interaction of the opposite charges, as it is typically understood that like charges repel while opposite charges attract. Some participants suggest that the static electric force may be negligible, raising questions about the problem's accuracy. Clarification on the charges and their effects on equilibrium is needed for a proper solution.
aaronmilk3
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Two small spheres, each of mass 4.00 g, are suspended by light strings 10.0 cm in length. A uniform electric field is applied in the x direction. The spheres have charges equal to -2.00 multiplied by 10^-8 C and +2.00 multiplied by 10^-8 C. Determine the electric field that enables the spheres to be in equilibrium at an angle of θ = 15.0°.

Here is a link to the image:
http://img.photobucket.com/albums/v720/lackofrespect/p23-62.gif

m1 = 4.00g
m2 = 4.00g
θ = 15.0°

I thought I might use E = (k|q||q|)/r²

I'm confused about the charges on the two spheres. How are they apart if they have opposite charges? Shouldn't it be that only like charges can repel and be in equilibrium?

Any help would be great to get me started.Thank you.
 
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welcome to pf!

hi aaronmilk3! welcome to pf! :wink:
aaronmilk3 said:
I'm confused about the charges on the two spheres. How are they apart if they have opposite charges? Shouldn't it be that only like charges can repel and be in equilibrium?

Any help would be great to get me started.Thank you.

hmm … that is odd! :redface:

i'll guess that the static electric force is so small that it can be ignored …

does that work? :smile:​
 
This is a problem from Web Assign which is a website you are assigned homework through. I'm wondering if there is an error and both charges should have been positive.
 

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