Can there be an electric field at a point where there is no charge? Can there be a charge at a place where there is no field? Please write a one or two sentence answer to each of these questions.

Let's say you are holding two tennis balls (one in each hand) and let's say these balls each have a charge Q. Estimate the maximum value of Q so that the balls do not repel each other so hard that you can't hold on to them.

Is it possible for two electric field lines to cross? If so, under what conditions? Do electric field lines ever end? If so, under what conditions?

Near its surface, the earth has an electric field that points straight down and has a magnitude of about 150 N/C. Estimate the charge that you would have to place on a basketball so that the electric force on the ball would balance its weight.