2048 Welcome to 2048 Dr. Jeffrey B. Bindell bindell@physics.ucf.edu www.physics.ucf.edu/~bindell 2048 Welcome to 2048 9/17/2018 2048 Ch. 1-2

Class Meets Monday, Wednesday, Friday 10:30-11:20 AM 9/17/2018 2048 Ch. 1-2

Textbook Physics for Engineers and Scientists Volume I (Mechanics) Serway & Jewitt Thompson – Brooks/Cole (2004) 9/17/2018 2048 Ch. 1-2

OFFICE HOURS: M,W,F 7:30-9:30 AM General Information Instructor: Dr. Jeffrey Bindell Schedule M,W,F 10:30 AM to 11:20 AM Room 359 Phone 407-823-4194 E-mail: bindell@physics.ucf.edu Website: www.physics.ucf.edu/~bindell OFFICE HOURS: M,W,F 7:30-9:30 AM 11:30-12:30 (Pot Luck) MAP-417 9/17/2018 2048 Ch. 1-2

This is a HARD Course! Reminder 9/17/2018 2048 Ch. 1-2

Grades Item Weight Mid Semester Examinations 45% Final Examination 30% Homework 15% In Class Quizzes 10% 9/17/2018 2048 Ch. 1-2

Homework It is important to notice that homework counts for 15% of your grade. Homeworks will be based on WebAssign. Although “extensions” will be available, valid reasons should be offered at the time or he request. There will be one or two assignments per chapter. Each assignment will contain between 5 and 12 problems (usually). You must complete the assignment before the due time or you must request an extension. You will need a reason. 9/17/2018 2048 Ch. 1-2

No Curve SCORE GRADE 85-100 A 75-84 B 60-74 C 50-59 D Less than 50 F 9/17/2018 2048 Ch. 1-2

Approximate Exam Schedule EXAM NUMBER DATE 1 1/27 2 2/10 4 3/31 FINAL EXAM 5/1 9/17/2018 2048 Ch. 1-2

TENTATIVE 9/17/2018 2048 Ch. 1-2 PHY 2048 WEEK DATE MON WED FRI 1 9-Jan Intro. + Ch 1 Topics Ch 2: 1 D Motion 2 16-Jan HOLIDAY Ch 3: Vectors 3 23-Jan EXAM #1 4 30-Jan Ch 4: 2D Motion 5 6-Feb Ch: 5: Laws of Motion 6 13-Feb 7 20-Feb EXAM #2 Ch 6: Circlular Motion 8 27-Feb Ch 7: Work & Energy 9 6-Mar Ch 8: Potential Energy 10 13-Mar BREAK 11 20-Mar Ch 9: Momentum 12 27-Mar EXAM #3 Ch 10: Rotation 13 3-Apr Ch 11: Angular Mom. 14 10-Apr Ch 12: Statics 15 17-Apr Ch 15: Oscillations 16 24-Apr No Class 17 1-May FINAL EXAM 9/17/2018 2048 Ch. 1-2

WebAssign You need to purchase a WebAssign login either from the bookstore or from the WebAssign website (with credit card). For your first contact with WebAssign, go to: http://www.webassign.net/info/support/access_codes.html Follow the guides to purchase a registration or to Login. The left side of the page has a scroll down menu that should get you where you need to get. Be sure to bookmark the final login screen because you will be using it quite a bit (I hope). Your login ID is your PIN with (or possibly without) the leading “0” and without any letters from your first name. Your password has been set to “ihatephysics”. After a successful login, be sure to change your password to something else to protect the privacy of your account. 9/17/2018 2048 Ch. 1-2

ratemyprofessors.com Completely unforgiving. Unhelpful office hours from which you leave more confused and with more questions than you came with. Seems to have no time for students, will not listen to any excuse, reasonable or not. Do not be 1 minute late on quiz day. Family emergency, car trouble= unforgivable sin Very difficult. Not in a tough way, but in an unhelpful way. Does not go over problems and his office hours are not helpful at all. You leave just as confused. Does not go over tests.  9/17/2018 2048 Ch. 1-2

ratemyprofessors.com Waiting for grades to come in. Have no idea if I passes or failed. Tests are UNFAIR, GRADING IS UNFAIR. I didn't miss more than a day of class. This class is an experiment and I don't like being the guinea pig when my GPA is on the line. Something better give or EVERYONE in the class will fail.  This was a SCALE-UP Course 9/17/2018 2048 Ch. 1-2

ratemyprofessors.com this class sucks, but bindell makes it doable. He answers ?'s, speaks clearly, and is pretty funny too. Fair tests and decent curves for the final grade. Do your webassign and make yourself known, you will pass this class...  Very hard class.Tests consist of 1 homework problem and 2 unseen problems, one easy, one hard.If you go to office hours(if you can get him on a day he's there)he will usually give you extra points on tests that TA's graded unfairly. He also curves the grades a lot.I was looking at a C and made an A  9/17/2018 2048 Ch. 1-2

ratemyprofessors.com Tough class. Bindell is a funny guy and does a pretty good job teaching. Just make sure that you study and don't fall behind.  Physics II is hard, no doubting that. But Jeff is by far a VERY reasonable professor. Speaks clearly, reasonable weekly quizzes, very flexible with webassigns, and wants the class to do well. Here is something I learned the hard way: STUDY HARD FOR THE TESTS, IF YOU DO NOT, YOU WILL FAIL THEM. PERIOD.  It is men like this that keep UCF from being considered an elite public uninversity. The man is comepletely and utterly ingorant of how to convey a concept to another human being. He wont answer questions. His tests are not representative of the material. He will show you reviews such as this and refute them. Don't listen. Get out at all costs.  9/17/2018 2048 Ch. 1-2

F includes people who forgot to withdraw and just stopped attending. The Facts … Spring ‘05 F includes people who forgot to withdraw and just stopped attending. 9/17/2018 2048 Ch. 1-2

What I learned: Students don’t like lectures, especially PowerPoint. Students don’t like WebAssign Some problems too hard Some problems are not coded correctly by WA. Students don’t like tests unless they are easy. They’re NOT! Course is hard, why would tests be easy??? 9/17/2018 2048 Ch. 1-2

My gripes …. Students study at the last minute. Students have big holes in their math skills: Interpreting Graphs. Using Calculus. Students come to my office expecting me to solve their homework problems. I will always help … I will not give you the answers! Work on the problems before you come for help. 9/17/2018 2048 Ch. 1-2

How to get an A. STUDY ! 9/17/2018 2048 Ch. 1-2

PHY2049 Mechanics The physics of how classical objects move. Terms mass, distance, time Force, torque displacement, speed, acceleration momentum, energy angular analogs Issues for many students calculus, graphical interpretation 9/17/2018 2048 Ch. 1-2

Important Definitions Length or Distance How “far” something moves or travels. Measured against some agreed upon standard. Length Standard .. The Gorf 1 2 3 4 1/8 = 4 1/8 Gorfs Unknown Length 9/17/2018 2048 Ch. 1-2

Systems of Units SI Units …. Meters, Seconds, Newtons/Kilograms English System ….. Feet/yards, seconds, pounds/poundals 9/17/2018 2048 Ch. 1-2

The yard One postulate was that the yard was derived from the girth  of a person's waist, while another claim held that the measure was invented by Henry I of England  as being the distance between the tip of his nose and the end of his thumb. These are believed to be more likely standardizing events as opposed to an actual coining of the measure. 9/17/2018 2048 Ch. 1-2

The real standard: The Meter More better .. 9/17/2018 2048 Ch. 1-2

More Important Definitions TIME The subjective “distance” between two EVENTS. It needs to be objective … ie measurable and reproducible. Original Clock – The Earth’s Rotation “It is two days journey” Today’s Clocks – “He ran the race in 4 hours, 2 minutes and 21.85 seconds” 9/17/2018 2048 Ch. 1-2

DEFINITION – The Second of Time Unit of time (second)        The unit of time, the second, was defined originally as the fraction 1/86 400 of the mean solar day. The exact definition of "mean solar day" was left to astronomical theories. However, measurement showed that irregularities in the rotation of the Earth could not be taken into account by the theory and have the effect that this definition does not allow the required accuracy to be achieved. In order to define the unit of time more precisely, the 11th CGPM (1960) adopted a definition given by the International Astronomical Union which was based on the tropical year. Experimental work had, however, already shown that an atomic standard of time-interval, based on a transition between two energy levels of an atom or a molecule, could be realized and reproduced much more precisely. Considering that a very precise definition of the unit of time is indispensable for the International System, the 13th CGPM (1967) decided to replace the definition of the second by the following (affirmed by the CIPM in 1997 that this definition refers to a cesium atom in its ground state at a temperature of 0 K): The second is the duration of 9 192 631 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom. 9/17/2018 2048 Ch. 1-2

What should you remember from the previous slide? The second used to be defined as some fraction of the length of the average day. The second is now defined as the time it takes for some mysterious atomic process to occur. This is something that can be measured in the laboratory. This serves as a STANDARD for time. 9/17/2018 2048 Ch. 1-2

Sun Clock 9/17/2018 2048 Ch. 1-2

Water Clocks 9/17/2018 2048 Ch. 1-2

Pendulum Clocks We will study how a pendulum works later in the semester. 9/17/2018 2048 Ch. 1-2

Cuckoo Clock Cuckoo’s are not covered in this class. 9/17/2018 2048 Ch. 1-2

And so on … Rolex (~$10K) Atomic Clock (NASA) $ megabucks 9/17/2018 2048 Ch. 1-2

Mass The Standard Kilogram A “quantity of matter”. Locked up in Paris. We have copy 9/17/2018 2048 Ch. 1-2

Prefixes 9/17/2018 2048 Ch. 1-2

Unit Conversion- How many seconds old are you? Assume you are exactly 21 years old and just qualified for your first legal drink. The Trick: Keep multiplying by one! 9/17/2018 2048 Ch. 1-2

Example 9/17/2018 2048 Ch. 1-2

So … =21 x 365 x 24 x 60 x 60 sec = 662,256,000 sec = 6.62 x 108 seconds 9/17/2018 2048 Ch. 1-2

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First WA Assignment is on board To think about SI Units Unit Conversion Significant Figures Dimensional Analysis We will do this throughout the semester. All discussed in Chapter 1 of the textbook. 9/17/2018 2048 Ch. 1-2

Going around in circles …  s=pathlength A x A  B x=displacement B t=time interval (A,B) = 10 seconds 9/17/2018 Seconds 2048 Ch. 1-2

 DEFINITIONS s=path length or total distance trraveled. B s x s=path length or total distance trraveled. x=displacement = NET distance traveled. Difference between final and initial position independent of the path. t=time of the trip. Usually measured in seconds. 9/17/2018 2048 Ch. 1-2

More Definitions average speed = distance traveled (s) / time taken [meters/sec.] average velocity= displacement/time [m/s] Note: the actual SYMBOL used for distance and displacement will usually change with the context of the problem. 9/17/2018 2048 Ch. 1-2

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-40m 10s 9/17/2018 2048 Ch. 1-2

In the limit - Dx Dt In the limit of Dt0, velocity is the slope of the tangent to the x-t curve! 9/17/2018 2048 Ch. 1-2

Example The position versus time for a certain particle moving along the x axis is shown in Figure P2.3. Find the average velocity in the time intervals (a) 0 to 2 s, (b) 0 to 4 s, (c) 2 s to 4 s, (d) 4 s to 7 s, (e) 0 to 8 s. 9/17/2018 2048 Ch. 1-2

A position-time graph for a particle moving along the x axis is shown in Figure P2.7. (a) Find the average velocity in the time interval t = 1.50 s to t = 4.00 s. (b) Determine the instantaneous velocity at t = 2.00 s by measuring the slope of the tangent line shown in the graph. (c) At what value of t is the velocity zero? 9/17/2018 2048 Ch. 1-2

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For v=constant 9/17/2018 2048 Ch. 1-2

Constant Velocity xf – xi= distance traveled = v t v x=0 xi xf MOTION DOESN’T ALWAYS START AT THE ORIGIN 9/17/2018 2048 Ch. 1-2

Question The position of a particle as a function of time is given by the equation below. (a) What is the position of the particle at t=2 seconds? (b) What is the velocity of the particle at t= 2 seconds? (c) At what time is the particle’s velocity = 0? (d) Is the particle ever at the origin? When? 9/17/2018 2048 Ch. 1-2

Oops … no solution! x What does t<0 mean?? t 9/17/2018 2048 Ch. 1-2