Physics 114 Professor Fred Salsbury Office Hours: MWF 11-11:40am; M 1-2pm 301A Olinhttp:// Topics Covered Electricity and Magnetism E&M Waves Nuclear Physics Please Pick Up and READ the Course Policy &Syllabus
Class Participation Cut out your voting cards and bring them to every class If you forget them, borrow some from me If you lose them, get new ones from me We will be using them for Concept quizzes in-class
Reading Assignments and Quizzes Reading Assignments Required: Every Lecture starting Wed; quizzes cover Recommended: Applications Online exercises Extra: More rigorous mathematical treatments Recommended and Extra will be on reserve at the library Along with two mathematics review texts. Reading quizzes, due 7am before every lecture; starting Wed A few submissions per problems Work by yourself
Homework and Semester Quizzes Homework Assignments Required: Every Lecture Starting Friday Several Submissions Encouraged to work with others, but you must submit your own work. Semester quizzes Four – see syllabus for datyes Lowest score is weighted ½
Grading Final Exam 330 points Semester Quizzes 350 points Laboratory,Homework and Reading Quizzes 320 points Total 1000 points If you miss any semester quiz or exam, I need a note from a medical doctor or the Dean’s office. You must pass lab to pass the course. You are expected to pass the final.
Webassign Username is your Institution is wfu Password (if new to webassign) is your student number If you have used webassign before use your old password. Log into webassign ASAP. If you have difficulty, contact me. There is a test homework on using webassign.
Web Information How to access course info: Go to Click on teaching There will be a page for general announcements, and a sidebar filled with useful information; including lecture notes. This course does not use blackboard.
Survey Online at webassign Worth 2 points if completed Due Wednesday To provide me with a idea of your backgrounds and expectations, and tutorial times.
Coordinate systems Different ways of representing space, and physics. Some problems are easier in some coordinate systems, but the physics is invariant. Cartesian Coordinates:
Polar Coordinates Another popular coordinate system, along with cylindrical and spherical
Vectors: Magnitude and direction Scalars: Magnitude Vectors and Scalars Displacement is a vector. Velocity is a vector. Acceleration is a vector.
The x- and y-components of a vector: The magnitude of a vector: The angle between vector and x-axis: Vector Components: Geometric
A = A x i + A y j Vector Components: Algebraic A unit vector is a dimensionless vector having a magnitude 1. Unit vectors are used to indicate a direction. i, j, k represent unit vectors along the x-, y- and z- direction. is another common notation. i, j, k form a right-handed coordinate system.
We want to calculate:R = A + B From diagram:R = (A x i + A y j) + (B x i + B y j) R = (A x + B x )i + (A y + By)j Vector Addition: Algebraic I R x = A x + B x R y = A y + B y The components of R:
The magnitude of R: The angle between vector R and x-axis: Vector Addition: Algebraic II
Vector Multiplication There are two ways (in 2 or 3D) to multiply vectors. Scalar product -> two vectors make a scalar Vector product -> two vectors make a vector Also called the dot product or the inner product Also called the cross product or the outer product
Scalar Product Scalar product -> two vectors make a scalar Geometric Algebraic
Vector Product Vector product -> two vectors make a vector Geometric Algebraic C has magnitude absin Direction perpendicular to the plane containing A and B.
The right hand rule velocity v Magnetic Field B Force F
Electricity and Magnetism One of the four fundamental forces of nature Responsible for the vast majority of what we observe around us Probably best-understood and best-tested of the forces of nature Electromagnetic Interactions: Electricity and Electronics Magnetism Chemistry Biology and even more
Electrical Charges Electric forces only affect objects with charge Charge is measured in Coulombs (C). A Coulomb is a lot of charge! Charge comes in both positive and negative quantities Charge is conserved – it can neither be created nor destroyed Charge is usually denoted by the letter q. An object has a total charge of 5 C. It is divided into two pieces, one of which has charge 8 C and the other of which has charge A)3 C B)-3 C C)13 C D)Such a division is impossible
Matter and Charges All matter is made of positive and negative charges (or neutral) An object’s total charge is very close to zero When an object becomes charged, a tiny fraction of its charged particles (usually electrons) are lost or gained These particles (usually electrons) can flow through objects Some materials are better at allowing the flow of electrons than others Conductor A material that allows electrons or other charged particles to flow freely Insulator A material that resists the flow of electrons and other charged particles
Elementary Charge Charges seem to come only in integer multiples of a fundamental charge unit called e We will treat e as a positive number (some sources treat it as negative) e = C know these Particleq Protone Neutron0 Electron-e Oxygen nuc.8e Calcium ion 2e Chlorine ion -e