# Homework Help: Eletric force problem

1. Apr 6, 2010

### zelda1850

1. The problem statement, all variables and given/known data

the magnitude of the electric field strength between two oppositly charged parallel metal plate is 2.0 x 10 3 newtons per coulomb. point p is located midway between the plates.

an electron is located at point p between the plates. caculate the magnitude of the force exerted by the electric field

2. Relevant equations

Felect = k • Q1 • Q2 / d2

k = 9.0 x 109 N•m2
q1 = 2.0 x 10 3
q2 = 2.0 x 10 3
d = missing

3. The attempt at a solution

how do i figure out the distance for this problem?

2. Apr 6, 2010

### Mintea

If you've already got the electric field, you don't need a distance; you can just use the fact that F=qE. If your field exerts 2000 Newtons of force on every Coulomb of charge in it, and your particle's charge is -1.6 * 10^-19 Coulombs or whatever (this may not be accurate; I don't exactly know the elementary charge off the top of my head) then you can just plug those in... This help any?

3. Apr 6, 2010

### rickz02

Coloumbs law can be also be written as $$F = qE$$.

You are given for the value of the electric field strength and charge of the electron is known to be -1.602e-19 C. Now you can calculate for the electric force exerted on the charge by the field.