The electrostatic force on a small sphere of charge 0.2 C due to another small sphere of charge -0.5 C has magnitude 0.4 N. k=

The electrostatic force on a small sphere of charge 0.2 µC due to another small sphere of charge -0.5 µC has magnitude 0.4 N. k= 8.99x109 Nm2 /C2 .

(a) Identify the nature of the force on the second sphere due to the first.

(b) Calculate the distance between the two spheres.