# Need some advice on this Electric Field question!

whatisphysics

## Homework Statement

What are the magnitude and direction of the electric field that will balance the weight of an
a)electron b)proton?

W=mg
E=F/q

## The Attempt at a Solution

This is what I did:

W=mg=F
so E=mg/q

My only question is, since W is downward, when I do my calculations, do I have to make it:
W=-mg=F
or do I simply just put it as W=+mg

If yes, why do i put it as +, or why do i leave it as negative, this is what i'm a bit confused about.

Homework Helper
hi whatisphysics!

What are the magnitude and direction of the electric field that will balance the weight of …

… so you need to give the direction of E, ie "up" or "down"

whatisphysics
hi whatisphysics!

… so you need to give the direction of E, ie "up" or "down"

That's the thing, I don't know if when I'm calculating the force acted by the gravity, which is W=mg, whether it should be a Positive or a Negative. I know how to do the calculations, Im just a little bit confused about the signs for W=mg.