Lecture 1 Purdue University, Physics 220 1 – Kinematics – Forces – Energy and Momentum – Rotations – Fluids – Oscillations/Waves/Sound – Thermodynamics Welcome to PHYSICS 220 (Section 1) Prof. Wei K. Cui Lecture 1 Purdue University, Physics 220 2 Class Format • Lecture Sections: – Instructors: Profs Wei Cui and Yulia Pushkar • Recitation Section 1: – Instructor: Mr. Deepak Pandey – CHIP coordinator: Dr. V.K. Saxena • Laboratory: – Coordinator: Dr. A. Lewicki – Lab Room: PHYS 121 Lecture 1 Purdue University, Physics 220 3 Course Web Site • Course Syllabus – Policies – Grading scheme – Exams & iClicker exercises • Lab Syllabus • Tentative Class Calendar – Pre-lecture reading assignments – Homework due dates • CHIP User’s Guide – Homework – Grades http://www.physics.purdue.edu/phys220 Lecture 1 Purdue University, Physics 220 4 Textbook The textbook is College Physics, Vol I, by Nicholas J. Giordano (Brooks/Cole). We will cover almost all of the topics in this volume, at a rate of one chapter per week! Very Fast! Come prepared! Lecture 1 Purdue University, Physics 220 5 Tips • Pre-lecture reading – Come to the lectures prepared! • Things to pay attention to – Concepts, connections, motivation: Lecture – Problem solving: Recitation + Homework – Hands-on lab • Taking notes – Lecture notes can be downloaded from the course web site – But they are sketchy … you need to fill in details in class • Post-lecture reading – See if there are still things you do not understand • Seeking help – See us during office hours! – Physics Help Center Lecture 1 Purdue University, Physics 220 6 Homework • We will use CHIP (Computerized Homework In Physics) for homework assignments • The homework is due by 10 am on Fridays • Homework is computer graded – 100% if completed before the deadline – 75% if completed within three days of the deadline – 50% if completed after three days but within one week of the deadline – 0% after one week past the deadline – There is a limit on the number of attempts allowed. Lecture 1 Purdue University, Physics 220 7 iClicker • We will use iClicker for interactive lecture and recitation exercises – One point for participating in each exercise – Two points for each correct answer • iClicker can be purchased at Purdue bookstores • Registration: – You must register your iClicker on CHIP! • Use serial number at the back of your iClicker • Go to CHIP -> Student Gradebook • DO NOT register on the iClicker web site! – Deadline: by the end of this week • We will start to use iClicker next week! Lecture 1 Purdue University, Physics 220 8 Exams and Grades • Exams: – There will be two midterm exams and one final exam. All exams are closed-book. The final exam will be cumulative. – Exam 1: Feb 22, 2010, 6:30 – 7:30 PM – Exam 2: Mar 29, 2010, 6:30 – 7:30 PM – Final: TBA (2 hours) • Grades: – The final grade will be determined on the following basis: • 300 points final exam • 300 points two evening exams (150 points each) • 150 points laboratory • 100 points CHIP homework • 50 points recitation exercises • 100 points lecture exercises – No excused iClicker exercises. – You must pass the lab in order to pass the course. Lecture 1 Purdue University, Physics 220 9 About Me An astrophysicist who loses sleep over black holes Want to learn more? Visit http://www.physics.purdue.edu/~cui Lecture 1 Purdue University, Physics 220 10 Units • To communicate the result of a measurement for a quantity, a unit must be defined! – Defining units allows everyone to relate to the same fundamental amount. – Always write down units and carry the units through all of the calculations. • We use the SI system – Length: meter (m) – Mass: kilogram (kg) – Time: second (s) • Dimensional Analysis: – Both sides of an equation must have the same units. – Can be used to verify equations, answers. 1 meter = 3.281 ft 1 kg = 2.205 pounds Significant Figures • There is an uncertainty associated with all measurements – Uncertainty is also called experimental error • Values are written using significant figures – A digit is significant if it is meaningful with regard to the accuracy of the value • Zeros may be ambiguous – Scientific notation helps clarify the significance of any zeros Lecture 1 Purdue University, Physics 220 12 Significant Figures: Examples Prefix (abbreviation) Power of Ten Peta (P) 10 15 Tera (T) 10 12 Giga (G) 10 9 Mega (M) 10 6 Kilo (k) 10 3 Hecto (h) 10 2 Deci (d) 10 -1 Centi (c) 10 -2 Milli (m) 10 -3 Micro (µ) 10 -6 Nano (n) 10 -9 Pico (p) 10 -12 Femto (f) 10 -15 Your height is: (A) 5.9 ft (B) 5.90 ft B is more accurate than A, as its result contains more significant figures. The approved financial bailout: $700,000,000,000 What about $7.0010 x 10 11 ? or $7 x 10 11 Lecture 1 Purdue University, Physics 220 13 Significant Figures - cont’d What is the perimeter of a circle of radius 1.2 m? What about: 3.1415 + 0.1 = 3.2415 or 0.1415 - 0.02 = 0.1215? Ans: 3.2 or 0.12 L = 2r = 2 x 3.1415926 … x 1.2 = 7.539822 …m L = 7.5 m Angle Measurements • Various units – Degrees – Radians – 360° = 2 π rad • Definition of radian – θ = s/ r • s is the length of arc • r is the radius • s and r must be measured in the same units Lecture 1 Purdue University, Physics 220 15 Trigonometry Lecture 1 Purdue University, Physics 220 16 Vector Lecture 1 Purdue University, Physics 220 17 Vector and Coordinate System Vector from Components • If you know the components, you can find the vector • Use the Pythagorean Theorem for the magnitude : • Use the tan -1 to find the direction: Wei Cui Lecture01.ppt