Newtonian Mechanics 8.01 W01D2

Why Study Physics

Textbook Authors: Young and Freedman University Physics 13 th Edition Volume 1

In-Class Active Participation Students are expected to complete daily reading assignments and hand in answers before the class Active Participation:  Concept Questions using Turning Point Clickers  Short Group/Table Problems with student presentation of work at boards  Mini-experiments and quantitative experiments

Weekly Schedule Mon/Tue: In-Class (2 hr): Hand in Answers to Mon/Tues Reading Question, Presentations, Concept Tests, Table Problems. Tue Night: Hand Written Problem Set due 9 pm, Math Review Nights 9-11 pm. Wed/Thurs: In-Class (2 hr): Hand in Answers to Wed/Thur Reading Questions, Presentation, Concept Tests, Table Problems, Experiments Fri In-Class (1 hr): Hand in Answers to Fri Reading Questions, Group Problem Solving, Mini-experiments. Sun: Tutoring Center Help Sessions from 1-5 pm in Office Hours: Faculty and TA office hours throughout the week

Problem Solving A MIT Education requires solving 10,000 Problems Measure understanding in technical and scientific courses Regular practice Expert Problem Solvers: Problem solving requires factual and procedural knowledge, knowledge of numerous models, plus skill in overall problem solving. Problems should not ‘lead students by the nose” but integrate synthetic and analytic understanding

Problem Solving/Exams In-Class Concept Questions and Table Problems In-Class Group Problems (Friday) Weekly Problem Sets 1. Multi-concept analytic problems 2. Pre-class Reading Questions 3. Pre-lab questions and analyze data from experiments Online “Mastering Physics” Practice Assignments: 1. One practice assignment per week with hints and tutorials 2. Review problems for exams Exams: Three Evening Exams and Final Exam

8 Guidelines for Collaboration Problem Sets: Please work together BUT Submit your own, uncopied work In Class Assignments: Must sign your own name to submitted work Signing another’s name is prohibited In Class Concept Questions: Use only your clicker Using another’s clicker is prohibited

Exam Dates Exam 1: Thurs Sept 22, 7:30 pm -9:30 pm Conflict Exam 1: Fri Sept 23, 9:00 am - noon Exam 2: Thurs Oct 27, 7:30 pm -9:30 pm Conflict Exam 2: Friday Oct 28, 9:00 am - noon Exam 3: Tues Nov 22, 7:30 pm -9:30 pm (Thanksgiving week) Conflict Exam 3: Wed Nov 23, 9:00 am - noon Final Exam: Date/time to be announced by Registrar Please do not buy plane tickets home without consulting these dates, especially for the Thanksgiving holiday.

Grading Policy  3 Exams + Final Exam = 15%+15%+15%+25% = 70% (Individual Work) You must pass the exam portion in order to pass the course.  Problem Sets 10% (Individual Work)  Reading Questions 5% (Individual Work)  Concept Questions 5% (Group Work)  In Class Work 10%: Experiments (Group Work) and Friday Problem Solving (Group Work)

Registering “Mastering Physics” (See instructions at mastering physics sign up info)mastering physics sign up info  Go to  Register with the access code in the front of the access kit in your new text, or pay with a credit card if you bought a used book.  WRITE DOWN YOUR NAME AND PASSWORD  Log on to masteringphysics.com with your new name and password.masteringphysics.com  The MIT zip code is  The Course ID: MPDOURMASHKIN40470

Website: web.mit.edu/8.01t/www 1. Course Information/Announcements 2. Daily Class Schedule 3. Presentations 4. Concept Questions and Solutions 5. Group Problems and Solutions 6. Experiments Write-ups 7. Problem Set Assignments and Solutions 8. Course Notes 9. Math Review Night Presentations 10. Exam Prep 11. Office and Tutoring Hours Stellar Site for Course Gradebook

8.01, 8.012, or 8.01L: which course is best suited for me?

Reasons for Working in Groups  Develop collaborative learning skills  Develop communication skills in Core Sciences  Create an environment conducive to learning and teaching for everyone in the class  Opportunity to ask teachers and peers more questions  Research labs or work places depend on group interactions

Coordinate Systems

Cartesian Coordinate System 1.An origin as the reference point 2.A set of coordinate axes with scales and labels 3.Choice of positive direction for each axis Coordinate system: used to describe the position of a point in space and consists of Cartesian Coordinate System

Vectors

Vector Reading Assignment: Young and Freedman: University Physics 13 th edition: th edition:

Vector A vector is a quantity that has both direction and magnitude. The magnitude of is denoted by

Application of Vectors (1) Vectors can exist at any point P in space. (2) Vectors have direction and magnitude. (3) Vector equality: Any two vectors that have the same direction and magnitude are equal no matter where in space they are located.

Vector Addition Let and be two vectors. Define a new vector, the “vector addition” of and, by the geometric construction shown in either figure “ head-to-tail ” “parallelogram”

Vector Decomposition Choose a coordinate system with an origin and axes. We can decompose a vector into component vectors along each coordinate axis, for example along the x, y, and z-axes of a Cartesian coordinate system. A vector at P can be decomposed into the vector sum:

Unit Vectors and Components The idea of multiplication by real numbers allows us to define a set of unit vectors at each point in space with Then vector decomposition becomes with components vectors: and components: Thus

Vector Decomposition in Two Dimensions Consider a vector x- and y components: Magnitude: Direction:

Vector Addition Vector Sum: Components

Worked Examples and Table Problems: Vectors Given two vectors, find: (a) (b) (c) (d) (e) a unit vector pointing in the direction of (f) a unit vector pointing in the direction of

Table Problem: Vector Decomposition Two horizontal ropes are attached to a post that is stuck in the ground. The ropes pull the post producing the vector forces and as shown in the figure. Find the direction and magnitude of the horizontal component of a third force on the post that will make the vector sum of forces on the post equal to zero.

Preview: Vector Description of Motion 1. Position 2. Displacement 3. Velocity 4. Acceleration

Table Problem: Displacement Vector At 2 am one morning, a person runs 250 m along the Infinite Corridor at MIT from Mass Ave to the end of Building 8, turns right at the end of the corridor and runs 178 m to the end of Building 2, and then turns right and runs 30 m down the hall. What is the direction and magnitude of the displacement vector between start and finish?

Things to Do For W01D3 Buy a Textbook (12 th ed., or 13 th ed.) Get “Mastering Physics” (comes with new textbook or purchase separately) and register Buy Clicker at MIT Coop Reading Assignment: Young and Freedman Sections , Answer Reading Questions Posted on Friday’s webpage to be handed in before class on friday