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Welcome to Physics 101!Lecture 01: Introduction to Forces“I am very excited about taking Physics 101!”“I look forward to taking the physics labs”“Im so nervous. dude so nervous”“Anxious” “very scared”“worried about my grade”“honestly terrified”“worried about math”“I am excited to learn about something other than s101/index.aspPhysics 101: Lecture 1, Pg 1
Physics 101 covers Forces Kinematics Energy/Momentum Rotations Fluids Waves/Sound ThermodynamicsPhysics 101: Lecture 1, Pg 2
Meet the Lecturer ProfessorTom Kuhlmantkuhlman@illinois.edu OfficeHoursMonday 9-10am315 Loomis; start next week Research» Biophysics: Gene regulation, genomeorganization, and intracellular diffusion» Physics Colloquium Sept 18 4PM, 141Loomis http://kuhlman.physics.illinois.edu/Physics 101: Lecture 1, Pg 3
Course Format(upward) Spiral LearningPreLectures iClickers Homework Lab Discussion 2525100150100 11 quizzes; drop lowest 1Hour Exams (3 x 100) Final Exam 3003001000Physics 101: Lecture 1, Pg 4
Excused (EX) Absences Can get excused Discussions Labs Examsabsences for: ONLY for: Illness Emergency Required attendance at University event Religious observance or practice Serving as volunteer emergency worker Absenceexcuses must be submitted within2 WEEKS of absence!Physics 101: Lecture 1, Pg 5
Step 1Step 2Physics 101: Lecture 1, Pg 6
Grading Scale950-1000 920-949 900-919 880-899 860-879 835-859 A AAB BB-810-834 780-809 750-779 720-749 690-719 610-689 610 C CCD DDF“My goal is to receive an A ”Physics 101: Lecture 1, Pg 7
Reading, Lecture, & Prelecture Needto complete Prelecture BEFORE Lecture! Answerprelectures 25/1000 points Due 6:00 am day of lecture. 1 point for honest attempt No EX, 28 Lectures can miss three and still get all 25points. Everyonegets 1 point for today!Physics 101: Lecture 1, Pg 8
P101 Lectures Participation is key! Come to lecture prepared! 1 point for each lecture using iclicker» No EX, 28 Lectures: can miss three and still get all 25 points.» Available at bookstore---register using link on our web page.» Using multiple clickers is an academic integrity violation. Not everything you need for exams! Concepts, Connections, Motivation Comprehensive Overview Calculations Hands-On LectureTextHomework, Discussion,Problem SectionsLabTaking Notes Lecture notes will be available on webpage.Physics 101: Lecture 1, Pg 9
P101 Homework Web based (byteShelf), immediate feedback 100% if done before 6:00 am deadline 90% credit on unfinished parts until following Tuesday 0% after that Always keep 5 significant figures! First one is due Tues Sept. 3!Physics 101: Lecture 1, Pg 10
Discussion Sections Director:Dr. Elaine Schulteeschulte@illinois.eduCourse Manager and Instructor Startstomorrow! Quizduring last 25 minutes of section;11 quizzes, drop lowest score Firstsection: math review, dimensionalanalysis.Physics 101: Lecture 1, Pg 11
P101 Labs Director:Professor Munir Nayfehm-nayfeh@illinois.eduresearch: Atomic and molecular physics First NoLab is Wed, Sept 4!“dropped” labs . Don’t miss one!Physics 101: Lecture 01, Pg 12
Problem Sections COMPLETELYVOLUNTARY NO points, credit, or brownie points! Sundayevenings 7-9 PM Loomis 141Starts this Sunday! I’llpost a list of suggested problems from yourtextbook the proceeding Friday Sundayevening I will work through them at thechalkboard in detail, and you should askquestions!Physics 101: Lecture 1, Pg 13
Email policy1.Read the course web site before emailing staff.2.Please DO NOT email physics or homeworkquestions. Use Office hours and Web Board.3.Send questions on Lectures, Prelectures, andClickers to Tom Kuhlman.4.Send questions on Discussion/Quizzes/Exams toElaine Schulte.5.Send questions on Labs to Munir Nayfeh.6.Your E-mail should have Physics 101 in thesubject linePhysics 101: Lecture 1, Pg 14
Physics Philosophy Quantitative approach to describing the naturalworld Action/reaction, reproducible experiment,MATHEMATICAL formulation Describe large number of “complicated”observations with a few simple ideas:APPROXIMATION Exams don’t have same problems, but do havesame IDEASPhysics 101: Lecture 1, Pg 15
Newton’s Laws of Motion1. NEWTON’S FIRST LAW:If there is zero net force on an object, thenits speed and direction will not change.Inertia2. NEWTON’S SECOND LAWAccelerationIf a nonzero net force is applied to anobject its motion will change FNet ma3. NEWTON’S THIRD LAWNet ForceMassThe forces that two interacting objectsexert on each other are equal in magnitudeand opposite in direction.Physics 101: Lecture 1, Pg 16
Example Forces in P101 Non-Contact G---- Gravity W G(Weight)M Earth mobject2rEarth 6.7x10-11 m3 / (kg s2) Earth: Mass 6x1024 kg, radius 6.4 x106 m. Contact Normal: Perpendicular to surface Friction: Parallel to surface Anything touching the object» Rope: Tension» Spring F kxPhysics 101: Lecture 1, Pg 17
Example: Weight of Object Calculatethe gravitational force (i.e. weight) on a3 kg book held 1 meter above the surface of theearth.W G MEarth m / rEarth2 (6.7x10-11 m3 / (kg s2)) (6x1024 kg) (3 kg)/ (6.4x106 1)2 m2 29.4 kg m/s2 29.4 Newtons (N)Physics 101: Lecture 1, Pg 18
Gravitational ACT If the book is raised 10 meters above thesurface of the earth, the book’s weight willbe:A)100 times strongerB) 10 times strongerC) Nearly the sameD) 10 times weakerE) 100 times weakerW G MEarth m / rEarth2 (6.7x10-11 m3 / (kg s2)) (6x1024 kg) (3 kg)/ (6.4x106 10)2 m2 29.4 kg m/s2Near surface of earth r 6.4x106 mW m (G MEarth /rEarth2) m (9.8 m/s2) mgPhysics 101: Lecture 1, Pg 19
Physics 101: Lecture 1, Pg 9 P101 Lectures Participation is key! Come to lecture prepared! 1 point for each lecture using iclicker » No EX, 28 Lectures: can miss three and still get all 25 points. » Available at bookstore---register using link on our web page.» Using multiple clickers is an academic integrity violation.
