Fill two rubber balloons with air. Suspend both of them from the same point and let them hang down on strings of equal length. Rub each with wool or on your hair, so that they hang apart with a noticeable separation from each other. Make order-of-magnitude estimates of
(a) The force on each,
(b) The charge on each,
(c) The field each creates at the center of the other, and
(d) The total flux of electric field created by each balloon. In your solution state the quantities you take as data and the values you measure or estimate for them.