Electric field due to point charge

[th3plan]

Homework Statement

Two particles are fixed to an x axis: particle 1 charge -2.00x10^-7 at x=6.0cm and particle 2 at 2.00x10^-7 C at x=21.0cm. Midway between the particles, what is there net electric field?

Homework Equations

E=kq/r^2

The Attempt at a Solution

Ok so I drew the picture out, and i know q1 is negative so the electrive field is going towards it to the left, and q2 is + so that means the field is going to the left toward q1, so that means Enet= -E1-E2 , and its negative because there both going to the left? Am i correct on this ? I know the rest of problem is just plugging in numbers, but whant to make sure I am correct on theory. Also let's say that q1 was positive does that mean q1 would go to the left, and q2 field would go to the right, resulting in a zero net force ?

 

[LowlyPion]

Homework Statement

Two particles are fixed to an x axis: particle 1 charge -2.00x10^-7 at x=6.0cm and particle 2 at 2.00x10^-7 C at x=21.0cm. Midway between the particles, what is there net electric field?

Homework Equations

E=kq/r^2

The Attempt at a Solution

Ok so I drew the picture out, and i know q1 is negative so the electrive field is going towards it to the left, and q2 is + so that means the field is going to the left toward q1, so that means Enet= -E1-E2 , and its negative because there both going to the left? Am i correct on this ? I know the rest of problem is just plugging in numbers, but whant to make sure I am correct on theory. Also let's say that q1 was positive does that mean q1 would go to the left, and q2 field would go to the right, resulting in a zero net force ?

I'd say you have grasped the concepts. The E field of 0 in your follow up is however only at the mid point which I'm sure you already understand.