I got the answers already, I just need help with the answer to the third questio
ID: 2046175 • Letter: I
Question
I got the answers already, I just need help with the answer to the third question.This was the whole question and these were the answers.
-At a certain distance from a point charge, the potential and electric-field magnitude due to that charge are 4.68 V and 15.0 V/m , respectively. (Take the potential to be zero at infinity.)
What is the distance to the point charge?
d= 0.312 m
What is the magnitude of the charge?
Q= 1.62*10^(-10) C
Is the electric field directed toward or away from the point charge?
away
^^^ how am I supposed to assume that the electric field is pointing away (positive charge) given only MAGNITUDE of Q, d, U and V??
Explanation / Answer
I don't know about you, but the way the question was asked I feel like the answer was basically given. The phrase where the question indicates:
"At a certain distance from a point charge, the potential and electric-field magnitude due to that charge are 4.68 V and 15.0 V/m , respectively."
I took that to mean that the potential is 4.68 V and the electric-field magnitude is 15.0 V/m.
In that case, if the electric potential is positive then the charge has to be positive. Hence why the electric field would be pointing away from it.
Besides that I don't think you could've have deduced that the charge was positive.
When it comes to the electric field, it's usually a good thing to give just magnitude because the electric field is a vector, i.e. it has both magnitude and direction so there are many ways it can point.
Electric potential on the other hand is just a scalar. a negative potential just means that it's due to a negative charge.
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