Two point charges

[Dorian Gray]

Greetings Mathematicians,

I am having difficulties with the following problem

"Two point charges qa = 2.1 X 10^-8 C and qb= -4.0 qa are fixed in place 50 cm apart. Find the point along the straight line passing through the two charges at which the electric field is zero"


Here is my work so far.





I need help finding x in the problem above. Thank you for any guidance!

 

[MarkFL]

I would back up one step, cross multiply, then solve the resulting quadratic in x.

 

[Dorian Gray]

is this correct?

Thanks for your response! I took your suggestion. Does this look right?

 

[Deleted member 4993]

Thanks for your response! I took your suggestion. Does this look right?

View attachment 2562

the term out side the radical sign should be "8*d*q_A". Then you can factor out q_A and simplify it.

Check to make sure that your answer is within real domain!

 

[Dorian Gray]

the term out side the radical sign should be "8*d*q_A". Then you can factor out q_A and simplify it.

Check to make sure that your answer is within real domain!

Thanks for the tip!