8/29/191PhysicsCh 1:Concepts of Motion Goals•Models•Describing Motion & VectorsoUsing diagrams, graphs, picturesoKey quantities that describe motion§Time, Distance/Displacement, Speed/Velocity, Acceleration•Physics problem solving strategies•SI unit system & Conversion•Scientific Notation & prefixes•Interpreting DataoPrecision & uncertaintyPhysics•Most fundamental of all natural sciences•Deals with structure & behavior of matter•Concerned with discovery of fundamental laws of nature (describable in mathematical terms) & application of these laws to detailed study of all physical phenomenao1061 covers Mechanics & Oscillations
8/29/192Historical•“Astronomy was first science EVERYWHEREoWhere are we? When is it? How/Why?•1600s — Galileo & Newton — Mechanics•1700s-1800s — Thompson, Day, Joule — Heat•1800s — Maxwell — Electricity•Early to mid 1900s — Einstein, Schrödinger, Dirac, etc — QM•Mid 1900s to present— various — lasers, supercond, fusion, fission, semiconductors, chaos, black holes, Higgs, dark matter, dark energy, exoplanets, quantum computingMachu Picchu Winter SolsticeEclipse 2017
8/29/193Galileo Principle•Recognize scientific problem exists;•State hypothesis: educated guess about problem;•Predict consequences of hypothesis;•Perform experiments or make observations to see if predictions occur;•Formulate simplest general rule that organizes hypothesis, predictions & experimental results into theory.Models and TheoriesWhat is Science?Models and Theories•“All of Physics is either impossible or trivial. It is impossible until you understand it, and then it becomes trivial.”— Sir Ernest Rutherford•Once someone (Newton, Einstein, you?) isolates simples laws from complex systems they are understandable
8/29/194Word Problems – Set Up•Read problem first to see what are you looking for•Read each phrase to determine what quantities are given or implied & what sort of thing they measureoNot just number, but what sortof thing is it•Decide whether you need to convertunits•What relevant model(s)are applicableWord Problems – Solving•Sketchthe problem•Choose useful coordinate systemoUseful meaning that it alignswith some aspect of the physics that is going on•Write the problem algebraically using symbols both for knowns and unknowns •Solve algebraically for each quantity before putting in numbersWord Problems – Checking•Keep extra sig fig for intermediate values, but round off final answer to correct # sig fig•Make sure you list units and sign•Check for reasonablenessoNot crazy big, small, sign, direction, etc.