Introduction to PhysicsPhysics 109

Fall Semester, 2017Section 1 Meets at 9:30 AM,Section 2 Meets at 11:00 AM

Tuesday and Thursday

115 Workman CenterInstructor: Loren Jacobson

Course Objective and Approach• To give students a basic exposure to

Physics that will better prepare you for more rigorous courses that will be taken later on.

• Two Class Periods– A Classroom session, with a description of the

experiment topic, followed by students working multiple choice problems first individually and then working together.

– A Laboratory session in which we will perform the experiment scheduled for the Physics 121 class for that week.

Some new technology• In class, we will use I-clickers to record

your responses to the multiple choice questions.– These can be purchased, or obtained on loan

from the library• We will use my web site as a means of

posting the lecture notes as well as solutions to homework problems.

• The URL for this site is: http://infohost.nmt.edu/~ljacobso/phys109%2016.html

Textbook

• Essential College Physics, Volume 1 by Andrew Rex and Richard Wolfson.

• Addison Wesley, publishers• ISBN 978-0-321-61116-1• (you might find used copies on line...)

Information Posted on the Web Site:

• Chapter reading assignments and homework problems for the term

• Laboratory Experiments for each week of the term.– A detailed lab manual has been prepared in

order to guide your lab experiments.– We are using the lab room normally used by the

Physics 121 lab. Our sessions will use the same experimental setups.

My Particulars:• Retired from U. S. Air Force active duty in 1982• Retired from Los Alamos National Laboratory in 2003• Ph.D. in Metallurgy from U.C. Berkeley in 1968• Taught at NM Tech Spring 2000 on sabbatical from Los

Alamos• Taught Physics 109 eight times before this semester• Other courses...Physical Metallurgy, Statistical Design of

Experiments, Statics, Materials Processing Lab and Senior Design, Introduction to Materials

• Office: 343 Workman Formal hours: Tu. 2-5 PM.– (Informal hours: before or after class)– Phone; 505-670-5728 (my cell number..feel free to use)– E-mail: jacobsonla@yahoo.com

How did I get here?• Great Falls, Montana, 1956

– Originally aimed at Ceramic Engineering, but was offered a scholarship that I could not refuse.

– Did trigonometry problems working in a civil engineering office for a couple of months before entering college...

• Dartmouth College, 1956—1960– Bachelor of Arts in Engineering Science– Air Force Second Lt. Through ROTC

• U.C. Berkeley, 1960--1962 – MS in Ceramic Engineering

How? continued• Air Force Materials Laboratory, 1962—65

– First exposure to intermetallic compounds– Explained the ZrO2 phase transformation

• U.C. Berkeley, 1965—1968– Found the right advisor, John Dorn– Minored in Solid State Physics

• Wright-Patterson AFB, 1968—1977– Five different jobs in three different

organizations– Last two years as an intelligence analyst

How? concluded• Washington, D.C., 1977—1982

– One year in the Pentagon, Two at Andrews– Final two years at DARPA

• Rapid solidification and metal matrix composites• Supported work that eventually won a Nobel Prize

• LLNL, 1982—1986– Some intelligence work, some metallurgy

• LANL, 1986—2003– Beryllium and beryllium alloys

• NMT—invited to teach introductory physics, 2007

Class Assessment

• We will give the “Force Concept Inventory” at the beginning of the class.

• We will also give this Inventory at the end of the class.

• Results will be used to assess the effectiveness of the class. (Will NOT affect your grade!)

Grading• Grades will be based on the following:• Class participation 20%• Laboratory reports 20%• Homework 20%• Quizzes and midterm 20% • Final Exam 20%• It may be necessary to adjust these

percentages—you will be informed if so.

Course Methodology• After brief introduction, multiple choice

questions will be asked.• Students will give independent answers.• Then, teams will be formed to work out a

team answer.• Comparison of results will help determine

effectiveness of team approach.• Prior times-62% individual and 72% team

correct answers (approximately)

Homework Problems• Your textbook suggests three steps in

solving a problem: Organize and Plan, Solve and Reflect.

• When you work homework problems for this course, I require that you do several other steps: State what information you are given, State what is required for you to solve, Write down the steps you will take to solve the problem, Do a dimensional analysis, Draw whatever is needed and finally, Solve the Problem.

• I will give an example.

Example Problem• Compute the number of minutes in a 365

day year.• Given: a year has 365 days (also, a day has

24 hours and an hour has 60 minutes.)• Asked: How many minutes in the year?• Equation: days x hours x minutes• Dimensional Analysis:

Minutes/year=Days/year x Hours/Day x minutes/hour

• Solution: 365 x 24 x 60 = 525,600 min/yr

Laboratory Reports:

• Your report should follow my suggested outline.

• This outline (in the next slide) will be posted on the web site, and in the lab manual

• I will examine problems with spelling and grammar, in order to help you improve your writing.

Laboratory Report-OutlineLaboratory Title, Number, Date

Name:

Partners:

Purpose:

Procedure:

Data:

Analysis:

Results:

Discussion and Conclusions:

Laboratory Report

• I have included in the Laboratory Manual and on the web site a more detailed description of each of these report sections....please refer to it!!

Doing Physics

• What is Physics?– Physics is the science that tells us how and why

things work.• Why study Physics?

– No matter what your field of study, Physics is at the foundation of all other specific topics (even chemistry....)

Fields of Physics

• Mechanics– Governs motion– Emphasis, Classical Mechanics

• Thermodynamics– Heat, and its interactions with matter

• Electromagnetism– Optics

Additional Physics Specialties:

• Atmospheric Physics• Astrophysics (these two here at NMT)• Solid State Physics• Quantum Mechanics• Relativistic Mechanics• Atomic Physics• Nuclear Physics• Particle Physics

Other Physics Specialties

• High Energy Physics• Low Temperature Physics

Our Course Emphasis

• Classical Mechanics (Dimensions and phenomena we can directly sense)

• Units of measurement: SI or Standard International Units (next slide)

• Dimensional Analysis• Accuracy and Significant Figures

Measurements

• Length – Meter• Time – Second• Mass – Kilogram• Other SI Units:

– Ampere – electric current– Kelvin -- temperature– Mole – amount of a substance– Candela -- luminosity

Dimensional Analysis

• Distance = Speed x Time– L = (L/T) x T = L

• Energy = 0.5 (Mass x Speed2)– E = 0.5(M x (L/T)2 )

• Always check equations to make sure that the dimensions are correct.

Accuracy and Significant Figures

• Radius of Earth – 6.37 x 106 m.– This quantity has three significant figures

• Multiplying or Dividing– Result should have the same number of significant

figures as the number with east number of significant figures.

• Adding or Subtracting– Number of digits to right of decimal point should

equal the term with the smallest number of digits to the right of the decimal point.

A Significant Figures Problem

• A 3.6 cm long antenna is added to the front of an aircraft that is 41 m long. What is the overall length?– A. 41.036 m– B. 41.04 m– C. 41 m– D. 41.36 m

A Dimensional Analysis Problem

• An equation that will be encountered later is x = ½ a t2. What are the dimensions of a?– A. LT– B. L/T– C. T/L– D. L/T2

– E. T/L2

Next Period (Thursday, 24 August)

• Introduction to Laboratory and procedures• How many of you have been introduced to

Trigonometry?• Trigonometry is essential for the treatment

of vectors, and vectors are essential for full understanding of forces and their effects.