Coulomb's Law: A Physics Overview PDF

COULOMB’S LAW The Atom Electric Force Electric Charge Conservation of Charge Coulomb’s Law Conductors and Insulators Electrostatics - electric charges at rest - is the study of electric charges, the forces between them, and their behavior in materials Recall: There are four fundamental forces in n...

COULOMB’S LAW The Atom Electric Force Electric Charge Conservation of Charge Coulomb’s Law Conductors and Insulators Electrostatics - electric charges at rest - is the study of electric charges, the forces between them, and their behavior in materials Recall: There are four fundamental forces in nature: 1. Gravity 2. Weak Nuclear Force 3. Electromagnetic Force 4. Strong Nuclear Force For further readings, visit https://www.space.com/four-fundamental-forces.html Electric Forces The enormous attractive and repulsive electrical forces between the charges in Earth and the charges in your body balance out, leaving the relatively weaker force of gravity, which only attracts. Electric Forces - are created between all electric charges. - Because there are two kinds of charge (positive and negative) the electrical force between charges can attract or repel. Electric Forces: Attraction and Repulsion The Atom - Electrical forces arise from particles in atoms. - The protons in the nucleus attract the electrons and hold them in orbit. Electrons are attracted to protons, but electrons repel other electrons. The Atom - The fundamental electrical property to which the mutual attractions or repulsions between electrons or protons is attributed is called charge. - By convention, electrons are negatively charged and protons positively charged. - Neutrons have no charge, and are neither attracted nor repelled by charged particles. The Atom Here are some important facts about atoms: - Every atom has a positively charged nucleus surrounded by negatively charged electrons. - All electrons are identical. - The nucleus is composed of protons and neutrons. All protons are identical; similarly, all neutrons are identical. The Atom - Atoms usually have as many electrons as protons, so the atom has zero net charge. - A proton has nearly 2000 times the mass of an electron, but its positive charge is equal in magnitude to the negative charge of the electron. Electric charge - is a property of tiny particles in atoms. - The unit of electric charge is the coulomb (C). A quantity of charge should always be identified with a positive or a negative sign. The SI unit of charge is the coulomb, abbreviated C. A charge of 1 C is the charge of 6.24 × 1018 electrons. A coulomb represents the amount of charge that passes through a common 100-W light bulb in about one second. Conservation of Charge In a neutral atom, there are as many electrons as protons, so there is no net charge. If an electron is removed from an atom, the atom is no longer neutral. It has one more positive charge than negative charge. A charged atom is called an ion. Conservation of Charge A charged atom is called an ion. A positive ion has a net positive charge; it has lost one or more electrons. It is called a cation. A negative ion has a net negative charge; it has gained one or more extra electrons and is called an anion. The Principle of Conservation of Charge Electrons are neither created nor destroyed but are simply transferred from one material to another. This principle is known as conservation of charge. The Principle of Conservation of Charge Four methods by which charges are redistributed: 1. by friction 2. by conduction 3. by induction 4. by polarization The Principle of Conservation of Charge Charging By Friction: the transfer of electrons from one uncharged object to another by rubbing the two objects together. Some electrons can move to the other object when rubbing The Principle of Conservation of Charge Charging by Conduction: the transfer of electrons from one object to another by direct contact. The Principle of Conservation of Charge Charging by Induction: When a metal object is close to a negatively charged object, electrons are repelled by the field and move away from it. The close end of the metal object becomes positively charged, and the far end becomes negatively charged. This process is called induction. The Principle of Conservation of Charge Charging by Induction: The Principle of Conservation of Charge Charging by Polarization: In other materials, electrons only move within their own atoms. The electrons react to electric fields, resulting in individual atoms having charged ends that are attracted to charged objects. This is polarization. Parts of the objects are charged in opposite ways.