a. Which of the following observations directly support the hypothesis that matter is composed of equal amounts of positive and negative charge?

Group of answer choices

Uncharged metal is attracted by both positive and negative charge

Uncharged water is attracted by both positive and negative charge

Polarizing one of two unpolarized pieces of metal attached by a wire polarizes the other

Magnets align their magnetic north poles with the north pole of the Earth

b. Twoequally polarized pieces of amber hanging on string separated by 0.01 m (1 cm). The balancing force of the string due to the weight of the amber pieces is 0.0002 N. If the electric force constant Keis 910⁹ N m² / C², which of the following could be the charge of each piece of amber in coulombs?

c. Two pieces of rubbed amber suspended on insulating thread push each other apart with an electric force of 0.0002 N when separated by 0.01 m (1 cm). If the threads are pulled back (without discharging the amber) so that the pieces of amber are separated by 0.02 m (2 cm), what is the force with which each piece of amber pushes on the other at this separation?

d. Between two metal plates attached to a capacitor, an electric field points left to right. If a positively charged piece of rubbed glass is brought in between the plates, it will be pulled: