Finding electric field magnitude, electron acceleration, and zero field point

[devilz_krypt]

I need a lot of help with Coulomb's Law and Electric Fields?? Need HELP!

Homework Statement

Here are 3 of the 25 questions the i did not understand, in regards with electric fields and Coulomb's Law.

1. A small object of mass 2.0 g and charge of 1.8x10^-7 C "floats" in an electric field. Find the magnitude and direction of the field.

2. An electron is accelerated by a constant electric field of magnitude 300 N/C.
A) Find the acceleration of the electron.
B) How far will the electron travel in 3s?

3. Two charges lie along the x-axis. If q1= -9.0x10^-6 C is at x= 6m and q2= -8x10^-6 C at x= -4m, locate the point at which the electric field will be zero.

Please help me finish my test review, i have been very confused ever since we start Coulomb's Law and Electric Fields.

Homework Equations

F= ((k)(q1)(q2))/(r^2)
E= (k)(q)/(r^2)
F= qE

The reason I didnt submit my solution is because i have about 5 different solutions for each problem.

 

[Kurdt]

Submit the solution you think is best for each one.