General Physics 2: Chapter 21- Coulomb's law

What are the two types of electrical force?

Repulsion and Attraction

Repulsion v. Attraction

R: Like particles, pushing away

A: Opposite particles, pulling towards

What kind of property is electric charge?

Fundamental, intrinsic physical property, automatic to particles

Net charge of objects

Often 0 due to equal protons and electrons

Conductors

Allow charge to move freely through a substance

Insulators

Aka nonconductors, does not allow charge to move freely

Semiconductors

Falls in-between conductors and insulators

Superconductors

‘perfect’ conductors

Induced charge

separation of charges due to outside charges

How does structure determine electrical properties?

Ex. Conductors have conduction electrons that wander the solid, protons are always fixed

How can an object become positively charged?

Through a loss of electrons

Electrostatic force

slow-moving/stationary electric charges between two charged particles

Coulomb’s Law (Definition)

Force of attraction between two charged bodies

Coulomb’s Law (Equation)

F= k q1q2/r2

Unit: Coulomb

What is the main difference between Newton’s and Coulomb’s Law?

There are two types of charge, repulsion and attraction. Gravity only attracts.

Coulomb

Unit for charge, 1C=1A 1s

Coulomb’s Constant

k, 1/4piE0

k=8.99×10⁹ N m²/c²

aka electrostatic constant

Permittivity Constant

E_0, 8.85×10^-12 c²/N x M²

Electrostatic Shell theories

1. CP outside a shell w/ uniformly charge surface acts as if all charge is concentrated at the center

2. CP inside a shell w/ uniformly charge surface has no net force

Elementary Charge

smallest amount of charge, e = 1.602×10^-19 c

Quantize

concept explaining that some physical quantities can only be described w/ discrete values

Conservation of Charge

Net charge of an isolated system is always conserved

Charge Equation

q=ne