PHY 102 1nd EditionExam # 1 Study Guide Lectures: 1 - 11Lecture 1What is included in the outside world?Celestial = sun, moon, stars (regular, predictable, you can count on it)Terrestrial = trees, mountains, rivers, animals (close, tamable, knowable, good, but not as good as celestial)In-between = rain, snow, hurricane, tornado (always moving)Who were the first scientists?PriestsWhat explains observation?Theory (abandon theory if observation is wrong)What was Pythagoras’s theory and why didn’t it stick?All planets, stars, moon, and earth move uniformly around a central fire (not the sun) on circularpathsParallax = change in the line of sight --> Pythagoras could not detect the earth’s motionWhat was Plato’s theory and what did he discover?Everything moves around the earthPlanets do not move uniformlyWhat is retrograde motion?Change in directionWhat was Eudoxos’s theory?Planet is attached to one uniformly rotating sphere, attached to another uniformly rotating sphere, etc.Lecture 2What does Eudoxos mean when he says all spheres are concentric with the earth?Distance between planet and earth is fixedWhat did Aristarchus study and what did he figure out?Moon and SunThe moon is 1/3 (33%) of the size of the earth (improvement: 27%)Distance to the moon is about 25 times Earth’s diameter (improvement: 30x)Earth to sun distance is about 20 times the earth to moon distanceThe sun is 7 times the size of the earth*Discovered heliocentrism 1800 years before CopernicusWhat did Eratosthenes study?EarthHow big is the earth?Circumference = 25,000 milesRadius = 3,978 milesLecture 3What was Apollonius responsible for?Explaining retrograde motion as well as change in brightness through epicyclesInstead of concentric circles in the homocentric model, put the planet on a circle (epicycle) and let it move on a larger circle (deferent)What was Ptolemy’s theory that lasted 1400 years?All planets needed more than one epicycle to account for their motionGeocentric = epicycle after epicycleLecture 4What did Nicolaus Copernicus discover after Aristarchus?Heliocentrism – he placed the sun at the center of the universeWhat did Brache discover?Heliocentric and geocentric models were wrong, but said to improve on the better one (heliocentric)What are Kepler’s three laws of planetary motion?1. Each planet moves on an ellipse, with the sun at one of its foci2. The planet sweeps equal areas in equal time intervals & planets move faster when closerto the sun3. T2 = ka3 or (T1/T2)2 = (a1/a2)3Lecture 5 – SNOW DAYLecture 6 – BLUE BOOK PROBLEMSLecture 7What is rectilinear motion?The simplest form of motionDisplacement, velocity, acceleration describe this motionWhat is the simplest form of rectilinear motion?Uniform motion (velocity does not change)x = vtWhat is acceleration? Change in velocity/timea = ∆v/∆t∆v can be positive or negativeWhat is uniformly accelerated motion?Acceleration does not changev = at + vox = vot + ½at2Lecture 8How is motion described?In relation to an observerObserver is not moving (object moves relative to observer)What is the difference between average velocity and average speed?Average velocity is a vector (arrow) and average speed is distanceLecture 9What is Aristotle’s observation of motion that was proven completely wrong? “All moving objects are being pushed or pulled”Who is Galileo?The father of modern scienceWhat is underdetermination?Infinite theories and each theory is as valid as the other’sThe truth of no theory or statement can be determinedHow does a wood block sliding down an incline describe Galileo’s first law of motion?On an infinitely smooth, horizontal surface, an object needs no push or pull to moveLecture 10What does the first law of motion also state?The momentum of an isolated system does not changeWhat is the key formula to know for the first law?p = mvp is momentum, m is mass, v is velocityunit for p is kg*m/sLecture 11What is the formula for the second law of motion?Fnet = maF is forceUnit for F is Newtons (N)What are the two types of forces?1. Contact (push/pull, friction, drag)2. Action at a distance (gravity)What is the difference between normal force and friction force?Normal = balances gravity (coming from the earth)Friction = opposite direction of