Physics: Coulombs Law

Question

1. Particles of charge +65 μC, +48 μC and -95 μC are placed in a line. The center one is 0.35 m from each other of the others. Calculate the net force on each charge due to the other two. 
2. Determine the magnitude and direction of the electric force on an electron in a uniform electric field of strength 2460 N/C that points due east.

Answer 1

The equation for the electrostatic force between charges q and Q a distance r apart is

F = k q Q / r^2

SI units are Newtons, Coulombs, and meters.

You'll have to look up k, but it might be 9 x 10^9. (I forget).

These vectors all line up, so add or subtract them to find net force.

F = q E,

and E is the electric field, N/Coul,

where q is charge on an electron is negative, the force should be due west.

If the field is due East, and the