# Electrostatic potential and electric field of three charges

• Ugnius

#### Ugnius

Homework Statement
Three point charges, q1=q3=9.5 uC and q2=1.28*10^-18 C are placed as shown in picture
a) How strong in electric field in point (0,0), affected by q1 ir q3 . b)Electric potential in point (0,0) affected by q1 ir q3 charges. Let's say electric potential at infinity is 0.
Relevant Equations
V=kq/r ; E=F/q

So I started with b)

and it there was no q2 this would seem reasonable
I was wanted to ask , what effect does q2 have on potential of these two charges? Because it has to be given for a reason.

I was wanted to ask , what effect does q2 have on potential of these two charges? Because it has to be given for a reason.
q2 does not play a role in answering (a) and (b). Your answer for (b) looks correct.

It does seem a little odd that q2 is given but q2 doesn't affect the answer. The very small value for q2 might indicate that it is to be thought of as a small "test charge". But, still, it is not relevant.

The phrase "affected by q1 ir q3" is also a bit odd. "effected" might be better than "affected". And I don't understand "ir".

q2 does not play a role in answering (a) and (b). Your answer for (b) looks correct.

It does seem a little odd that q2 is given but q2 doesn't affect the answer. The very small value for q2 might indicate that it is to be thought of as a small "test charge". But, still, it is not relevant.

The phrase "affected by q1 ir q3" is also a bit odd. "effected" might be better than "affected". And I don't understand "ir".
Yes , sorry , I had to translate statement from my native to English , so I might've done some mistakes. I realized that q2 was just a trick to make us doubt our solutions. I sent it , and it seems to be correct.

TSny
Yes , sorry , I had to translate statement from my native to English , so I might've done some mistakes.
OK. That's no problem.

Ugnius