Physics - Chapter 19

19.1 §

• Magnitude of an Electron’s Charge, e
  • e = 1.60 * 10${}^{-19}$ C
  • SI Unit: coulomb (C)
• Mass of electron (m${}_e$) = 9.11 * 10${}^{-31}$ kg
• Mass of protons (m${}_p$) = 1.673 * 10${}^{-27}$ kg
• Mass of neutrons (m${}_n$) = 1.675 * 10${}^{-27}$ kg
• Charge Quantization - Electric charge always comes in amounts that are always integer multiples of e
• Electric charge is conserved, total electric charge in the universe is constant
• Polarization - Mechanism that makes it possible for a charged rod to attract small objects that have zero total charge
• Insulators - A material that is poor at conducting thermal energy / electric charge
• Conductor - A material that is good at conducting thermal energy / electric charge
• Semiconductor - A material with properties between those of a good conductor and a good insulator

19.2 §

• The electrostatic force depends on the product of the magnitude of the charges
• Coulomb's Law: F = k$\frac{|q1||q2|}{r^2}$
  • SI Unit: Newton (N)
  • k = 8.99 * 10${}^9$ N * m${}^2$/C${}^2$
• Electric force can be attractive or repulsive therefore the total electric force between neutral objects, such as the Earth and Moon, is essentially zero. Attractive and repulsive forces can cancel each other out