What Electric Field Balances a Proton Against Gravity?

[dminus]

Homework Statement

A proton near the surface of the Earth is in equilibrium under the force of gravity and the force of an electric field. What electric field is required?

Homework Equations

m(proton)=1.67x10^-27

The Attempt at a Solution

I found the force of gravity on the proton which is F=1.63^²⁶ by multiplying the proton with the acceleration of Earth F=ma
I don't know how to find the electric field. I try using the formula E=F/Q, the Q being 1.6x10¹⁹.

Problem is here
http://books.google.com/books?id=vN...the origin has a magnitude of 845 N/C&f=false

Page 96 question 3.47

OH NVM I GOT IT XD

 

[lippyka]

The electric field required is F/Q, where F is the force of gravity and Q is the charge of the proton. Therefore, the electric field would be 1.63x10^-26/1.6x10^-19 = 1.0125x10^7 N/C