General College Physics

Wisconsin Lutheran High School

Week 10

Reading: PSE Chap 7, Work and Energy

Topics: This week, we begin discussing the concepts of work, kinetic and potential energy, energy conservation, and power

Lab:

Homework Problems: Due on Wed. Oct. 25.

David's sling: Solution. King David, facing Goliath, swings a stone in the pouch of a sling above his head. The trajectory of the stone is in a circle whose plane is parallel to the ground. The sling is of length L = 1 meter; the stone is of mass m = 200 grams. The rotation rate is twice per second. Ignore gravity and drag (let's focus on the circular motion). (i) Draw a free body diagram for the stone at a particular instant. (ii) What is the speed of the stone? Is it accelerating? If so, in which direction? (iii) What is the tension in the string? What would happen if the string snapped?
Race track: Solution. A 2000 kg race car rounds a curve at 150 mph. The radius of curvature of the track is 100 meters. What is the minimum coefficient of friction between the tires and the road so that the car does not slide?
Sled on a pond: Solution. A sled of mass m is given a kick so it is sliding across a frozen pond at an initial speed of 2 m/s. The coefficient of kinetic friction between the sled and the ice is 0.10. Using energy considerations, find the distance the sled moves before coming to a stop. Hint: the friction force is doing work on the sled.
Climbing gymnast: Solution. A 50 kg gymnast climbs a 10 meter high vertical rope in 5 seconds. Find the average power output of the gymnast in climbing the rope.

Midterm: We will have a Midterm on Monday, Oct. 17.

Mid-term grade estimation: I will be curving the grades for this class. Here is an estimate your midterm grade. Look at your current on-campus grade. If you are currently scoring

above you are getting
###### ##############
93 A
85 A-
72 B+
68 B
else B-

General College Physics

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/WLHS1/

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.

Software: Logger Pro 3.15 Is an excellent data analysis software package. Download for Wndows 10, 8.1, 7, and for macOS 10.14, 10.13, 10.12, 10.11, 10.10. For more details on how to download and install Logger Pro click here.