Question

I don't know what this question is asking of me....

A small test charge is released at rest at a point in an electrostatic field configuration. Will it travel along the field line passing through that point?

Answer 1

Do u know the formula
F=qE

Answer 2

F=electrical force on the charge q

Answer 3

E=electric field

Answer 4

So the direction of F and E are same if the charge is positive

Answer 5

And
F=-qE

Answer 6

If the charge is negative

Answer 7

The negative charge feels the electrical force oposit to the direction of electric field

Answer 8

https://www.physicsforums.com/threads/do-charges-travel-along-field-lines.368400/

Answer 9

So initially, it will follow the field lines, but as its velocity increases, no it won't directly follow the field lines

So I guess it won't "travel along" the field line.

Answer 10

Basically as its speed increases, assuming the field lines are curved...

Remember field lines show the direction of force (which is the direction of acceleration). Even if it starts at zero velocity, eventually it gains significant velocity.

Answer 11

Imagine the black line as a field line. Even if the particle starts at rest... Let's say somehow the particle continues travelling along the field line... it's always being accelerated, right?

So it's velocity continually increases, meaning it's going to need more and more force to keep it travelling along the field line as it speeds up (since it's similar to circular motion on that diagram).

Since in reality, the force isn't going to continually increase, this is why the particle will not follow the field line for very long.

Answer 12

Thanks, for the help @agent0smith .

But I think the answer won't be straightaway NO.

It will be NOT NECESSARILY. It will be true only if the field line is a straightline.

Thanks again for the clearing of my conception, @agent0smith

Answer 13

"be straightaway NO." what do you mean by that?

Yes, you could say that it'll only follow the field line if the field line is straight.

Answer 14

I mean if I write "No" as an answer, that'll be wrong, since the field line will be followed in case of straight field line. So it isn't always 'no' in this case.

Answer 15

Oh, yeah but as long as you describe your answer correctly it's fine. I wouldn't just say "no" or "not necessarily", provide the reasoning.

Answer 16

Oh yeah, I will have to provide the explanation behind whatever my answer is, that I have to do.

Answer 17

Yo, @agent0smith , can you help me with this new question of mine?

Answer 18

Okay