General College Physics

Wisconsin Lutheran High School

Week 26 (Feb. 19 - 23)

Reading: Current and resistance (Chap. 27)

Key Topics: electric current, resistance, resistivity, ohm's law, joule heating

Homework Problems: Due Feb. 28 at noon

Power lines: High-voltage power lines deliver electrical current to your neighborhood. The aluminum wire used for these lines has a cross sectional area of about 5 square centimeters. What is the resistance of ten kilometers of this wire? (Answer: resistivity of aluminum * length / area = 0.52 ohms ) Hint: you will need to look up the resistivity of aluminum.
Car battery: A car battery has a rating of 220 ampere-hours. This rating is an indication of the total charge that the battery can provide to a circuit before failing. What is the total charge (in coulombs) that this battery stores? (Answer: an ampere is a coulomb per second. So 220 ampere-hours * 60 minutes/hour * 60 seconds/minute = 792,000 coulombs). What is the maximum current that the battery can provide for 38 minutes (Answer: 792,000 coulombs / 38 minutes = 347 amperes).
Mystery resistor: The current in a series circuit is 15.0 amperes. When an additional 8.00 ohm resistor is inserted in series, the current drops to 12.0 amperes. What is the resistance of the original circuit? (Answer: Since the voltage didn't change, the product of the current and the resistance remains constant. Thus, 15 amps * R = 12 ams * (R + 8). Solving for R gives R = 32 ohms)
Resistor combinations: Eight different values of resistance can be obtained by connecting together three resistors (1, 2 and 3 ohms) in all possible ways. What are they? (Answer: 6 (1, 2 and 3 all in series), 6/11 (1, 2, and 3 all in parallel), 11/5 (1 in series with 2 and.3 in parallel), 11/4 (2 in series with 1 and 3 in parallel), 11/3 (3 in series with 1 and 2 in parallel), 5/6 (1 in parallel with 2 and 3 in series), 3/2 (3 in parallel with 1 and 2 in series), 4/3 (2 in parallel with 1 and 3 in series))

General College Physics

2022

Return to course website.

Course syllabus

Physics: The world around us is in a state of constant change: the sun and moon rise and set, waves crash, mists rise, rain falls, fires burn, rocks form, and mountains crumble. Amidst all of these changes, there are certain patterns; there is a discernible order. In other words: the stars, the seas, the clouds, the rocks, and the earth itself each seem to have a particular nature. Physics is the careful study of the natures of things. In fact, the word physics literally means "natures" in the Greek language.

Course overview: General College Physics is a year-long introductory course for advanced (typically junior or senior level) students at Wisconsin Lutheran High School who want to better understand the natures of the things we see around us. It is a dual-credit course offered at Wisconsin Lutheran High School in collaboration with Wisconsin Lutheran College. For a detailed overview of the topics we will be covering, refer to the course website (www.greatphysics.com) and the tentative calendar on the following page. Emphasis on theoretical topics, careful thinking, laboratory experiments, and problem solving makes this course challenging. My aim is to help you succeed in this course, and to have fun while learning physics. So please do not hesitate to contact me with any problems you may run into this semester!

Advanced Placement credit: While this is not designated as an AP course, students students have successfully taken the AP Physics test at the end of the year for college credit.

Course textbook: The course will be organized around a book: the Pocket Guide to accompany Physics for Scientists and Engineers (4th edition) by Serway. (I’ll call this PSE for short.) I would highly recommend obtaining a copy of this book. It is inexpensive, compact, and well-written. It will make a very handy addition to your home science library. If you don't want to buy it, I will have copies to loan out for the semester.

Course time and location: The course meets every day (Monday through Friday) during the academic year from 2:16 until 3 pm in WLHS 223—in the science wing on the first floor of WLHS. On late start days (such as Wednesdays) the course begins at 2:24.

Professor: Dr. Kuehn from Wisconsin Lutheran College (WLC) is the professor for this course. Contact info: kerry.kuehn[at]wlhs.org

Teaching Assistant contact info: The Wednesday course sections (beginning in September) will be overseen by two teaching assistants. Alyssa Ebeling and Zeke Micheel are upper-level physics majors from Wisconsin Lutheran College. Here is their contact info: alyssa.ebeling[at]wlc.edu, ezekiel.micheel[at]wlc.edu

Course websites: In addition to the course information provided through WLHS’s OnCampus system, we will be also using a website I’ve designed for this course: www.greatphysics.com/WLHS2/

Homework exercises: I will assign weekly homework problems. These are designed to deepen your understanding of lecture material and to prepare you for the quizzes and tests. I do not intend to grade your homework solutions; I will merely give you credit for handing in your best attempt by the due date. Please refer to the late work policy for more details.

Laboratory exercises: Some of our weekly assignments will include laboratory work. Labs will typically take up at least two class periods. Your laboratory notebook pages must be submitted by the assigned due date. More details about the required format and expectations will be discussed before the first laboratory period. You will need to order/purchase a dedicated laboratory notebook. Here are guildlines on what to include in your laboratory notebook.

Quizzes: We will have in-class quizzes almost every week on Monday. To prepare for quizzes, you should read the assigned book chapter (at least once), review the lecture material, complete all of the homework problems, and review the homework solutions.

Tests: We will have a midterm exam before the end of the first (and third) quarters and a comprehensive final examination before the end of the second (and fourth) quarters.

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