Who knows how to do this?

1)   F = 8.789 10² N, 2)   F = 1.5 10⁴ N

Explanation:

We can solve this exercise using Coulomb's law

         F =

Knowing that charges of the same sign repel

let's apply this equation to our case

1) the charges are q = - 0.0025 C and the distance between them r = 8 m

       we calculate

           F = 9 10⁹ 0.0025 0.0025 /8²

           F = 8.789 10² N

as the two charges are of the same sign the force is repulsive

2) q₁ = -0.004C and q₂ = -0.003 C with a distance of r = 3.0 m

    we calculate

             F = 9 10⁹ 0.004 0.003 / 3²

             F = 1.5 10⁴ N

v 154.9= 0.9 length length s little over 154.9cm

this is poiselle's equation from fluid mechanic in physics. mech eng