The electric force between two charges is:
F = (9 x 10⁹) Q₁ Q₂ / D²
F is the force, in Newtons
Q₁ and Q₂ are the two charges, in Coulombs
D is the distance between them, in meters
For these two particles:
F = (9 x 10⁹) (0.35) (0.35) / (1)²
F = (9 x 0.35 x 0.35 x 10⁹) / (1)
<em>F = 1.10 x 10⁹ Newtons</em>
Thatsa lotta force . . . like <em>124 thousand tons</em> !
The reason it's so big is because the charges in this question are so big ... 0.35 Coulombs each. 1 Coulomb is a huge amount of charge.
Each of the particles feels the same force, pushing it away from the other particle. (The electric force between two charges is always the same in both directions, just like the gravitational force between two masses.)