A. M\" 1: INTERACTIONS OF ELECTRIC CHARGES I. - CHAPTER 1 THE INTERACTIONS OF ELECTRIC CHARGES in this chapter we will examine experimentally the basic aspects of electric interactions. Using three fundamental physical principles, conservation of charge. Coulomb's law. and the superposition principle, we will attempt to explain the results of our experiments. We will nd that certain observations cannot easily be explained. ' 1 .14 The basic properties of electric interactions Whether or not you have previously studied electricity. you have probably heard somewhere that electric interactions have the following basic properties: ' There are two kinds of charge! called \"+\" and \"-". - Like charges repel, unlike charges attract. ' The electric force: - is proportional to the amounts of both charges, - acts along a line between the charges, and - decreases rapidly as the distance between the charges increases. \\I,.,.- ..| , - ,- . . . p