What is the force of repulsion, the two spheres are placed in water?(dielectric constant of water = 80)

What is dielectric Constant?

Why water has very high dielectric constant?

What is the unit of dielectric constant?

Two insulated charged copper spheres A and B have their centres separated by a distance of 50 cm. What is the mutual force of electrostatic repulsion if the charge on each is 6.5 xx 10^-7 C ? The radii of A and B are negligible compared to the distance of separation. What is the force of repulsion if each sphere is charged double the above amount, and the distance between them is halved?

What is the force between two spheres weighing 40 kg each and placed 5 m apart?

Two small charged bodies interact in air with a force F. what will be the force of interaction between these bodies be after they are placed in a dielectric of permittivity K, if their potentials are kept the same as they were in air?