Announcements 9 1 09 1 Welcome to Physics 105 o I m Dr Colton Introductory Stuff Syllabus Course objectives pg 3 Schedule pg 1 2 Answers to two common questions o The Physics 107 Lab is completely separate from this course since it s not required for all majors I know practically nothing about it o There is no Blackboard site for this class Instead we ll use my own website details later 3 We ll go over the syllabus shortly Make a note of these corrections though o Wed office hours changed now Wed 2 30 4 pm Fri still 3 30 5 pm o Page 3 printing error look for it after page 6 Reading assignments for other editions pg 2 Grading pg 4 4 As most of you have found out already I send out periodic class wide emails via Route Y Make sure your email address there is current Colton Lecture 1 pg 1 Class website physics byu edu Courses Class Web Pages Physics 105 Colton J Takes you to Colton Lecture 1 pg 2 The best study aid the other students Take two minutes now to exchange names numbers emails with 3 4 people sitting near you http www physics byu edu faculty colton courses phy105 fall09 Warmup exercises Obtain CID student ID number for the class Register clicker Homework data sheets I ll talk about that a bit on Thurs Homework submission status Check your course grade Study aids a Class notes both before after class b Videos of demos c Link to Google group Homework discussion hints help d Sample exam problems e Exam solutions f Website links g Etc List of How to get started More stuff you should know from syllabus Four free warmup quizzes Read about them on Four free clicker quizzes your own Extra credit opportunities Colton Lecture 1 pg 3 First clicker quiz do the clicker quizzes if you have yours but they won t be recorded today I now have the names numbers emails of 3 4 other people in the class a True b False and now for the Physics Chapter 1 Units Trigonometry skipped but you need to know it don t need to know sig figs Colton Lecture 1 pg 4 x m 40 Chapter 2 Kinematics mathematical description of motion 20 Recording motion Choose an origin zero Choose a direction 0 20 40 60 20 80 t sec 100 120 40 x 300 m x 400 m x 0 The bus starts at x 200 m goes to your house and waits for you then takes you to school Table of position vs time x t t sec x m 0 200 20 300 50 300 120 400 x t plot of table assuming constant speed between events Where is the bus going the slowest not counting stops Where is it going the fastest When is it moving to the right When is it moving left Colton Lecture 1 pg 5 Colton Lecture 1 pg 6 Clicker quiz Nancy initially at point P in the illustration stays there a moment and then moves along the axis to Q and stays there a moment She then runs quickly to R stays there a moment and then strolls slowly back to P Which of the x t graphs below correctly represents this motion Position vs Displacement Position where something is located often labeled by x Displacement a change in position often labeled by x x xf x0 f final 0 initial pronounced naught What do we mean by position Being on the right left side of the origin What do we mean by displacement Has shifted to the right or left A B D E C Question what was Nancy s total change in position ambiguous Colton Lecture 1 pg 7 Clicker quiz What was Nancy s total displacement d 2 a 4 e 4 b 2 c 0 Clicker quiz What was Nancy s total distance traveled d 2 a 4 e 4 b 2 c 0 Colton Lecture 1 pg 8 Clicker quiz An object goes from one point in space to another After it arrives at its destination its displacement is compared to the distance traveled a either greater than or equal to b always greater than c always equal to d either smaller than or equal to e always smaller than Speed vs Velocity Hint draw a picture of some random path Slope velocity rate of change of position average velocity vave sometimes written v must always specify the time interval start end times Speed vs velocity are they the same thing Question A race car driver does 100 laps of a circular track at a constant 200 mph What was his average speed What was his average velocity Colton Lecture 1 pg 9 Problem On the Tour de Provo bicyclists ride straight south for 3 hours at 8 km hr rest for 2 hours then continue their ride south down a mountain for 1 hour at 20 km hr What is their average velocity for the morning From Problem Solving section of syllabus PEANuT Picture Equations Algebra Numbers Think Colton Lecture 1 pg 10 Instantaneous Velocity at a particular time The instantaneous velocity at a particular time is the average velocity over a very small time interval around that time slope of tangent line of the x t graph at that point x m 40 20 0 2 4 20 6 8 t sec 40 Positive slope means Negative slope means Zero slope means Colton Lecture 1 pg 11 Colton Lecture 1 pg 12 10 12 The shadow of a roller coaster car has the following leftright position on the ground x m 40 Summary What you need to do ASAP See also the How to get started section of the website Problem Find vx at 6 seconds in m s including direction Before class on Thursday Get CID via website if you weren t emailed one Get course packet Get textbook Get clicker Register clicker via course website Do reading assignment Do warm up exercise on website Clicker quiz During the ride the roller coaster stops and turns around times A 1 B 2 C 3 D 4 E 5 Before Saturday night Get individual homework data sheet via class website Do first homework assignment Submit HW via class website Clicker quiz The time it has the largest speed is closest to sec A 3 B 5 75 C 6 25 D 8 E 10 5 Optional but highly recommended Register for class Google group Read the syllabus regarding on line homework system 20 0 20 2 4 6 8 t sec 10 12 40 Clicker quiz At t 8 sec the car is moving to the A right B left C not moving Colton Lecture 1 pg 13 o We ll discuss briefly on Thurs Read the syllabus regarding other stuff extra credit departmental policies etc Colton Lecture 1 pg 14