Two charged balls are 10 cm apart. one is positively charged, and the other is negatively charged. describe the electric field lines and any forces that would exist between the two balls.

The field lines extend from the positive to negative charge.

Force between them is attractive.

Explanation:

The field lines of the electric charges extend from the positive to negative side charge. These are the parallel lines and they never cross each other when tho charges are kept infinitesimal distance apart.The distance between the two charges, x = 10 cm                                                                    The force between the two charged balls is attractive.It is directly proportional to the product of their charges and inversely proportional to the magnitude of the distance between them.It is given by the formula

                                C

Since distance between the two charges, x = 10 cm, the force between the charges is reduced by the factor 0.01 m² in SI units.  

Planck decided to assume that atoms could only vibrate at certain frequencies that were whole numbers eg 2f, 3f and so on. others used to think that atoms vibrate continuously

Electric force between two charged object varies inversely as the square of distance between them (coulomb's law). this means if two charged objects move away force between them decreases.