General College Physics

Wisconsin Lutheran High School

Week 36 (Apr. 28 - May 2)

Reading: Interference of light waves (Chap. 37)

Key Topics: electromagnetic waves, intensity, interference, and polarization

Week 36 Homework Problems:

Sunlight intensity: The intensity of sunlight is about 1000 Watts/square meter at the earth's surface. What is the amount of energy delivered during one hour to a 20 square meter solar panel? What is the amplitude of the electric field in the electromagnetic wave striking the solar panel? (Answer: 20,000 Joules per second * 3600 seconds = 72 MegaJoules.)
Laser intensity: A Neodymium-glass laser emits short pulses of high-intensity electromagnetic waves. The electric field has an amplitude of 3e9 Newtons per coulomb. Find the average power of each pulse that passes through a 1.6e-5 square meter surface perpendicular to the laser beam. (Answer: the intensity is 1.19 e16 watts/m^2. So the power is 191e9 Joules or 191 GigaJoules.)
Polarization of light problem
Skip this problem (we didn't get to it): Speed of light measurement: Foucault's spinning mirror apparatus. Find the minimum rotation rate of mirror 1 so that light (speed 300,000 km / sec) enters the telescope after bouncing from mirror 2, which is 3 km away. The light source and the telescope, and the telescope and mirror 2 are each separated by 1 degree. (Answer: the light must travel 6km by the time the mirror has rotated half a degree. So the mirror needs to rotate half a degree in 20 microseconds. Minimum rotation rate is 69 rotations per second.)

General College Physics

Return to course website.

Course syllabus

General College Physics is a year-long introductory college-level course for advanced (typically junior or senior level) students at Wisconsin Lutheran High School. It is a dual-credit course offered at Wisconsin Lutheran High School in collaboration with Wisconsin Lutheran College. This means that students enrolled in the course have the option of receiving credit for a four-credit algebra-based laboratory science course from the College.

During the first semester, we will primarily study the science of motion and its relationship to forces. Topics include: dimensional analysis, measurement, uncertainty, estimation, 2 dimensional kinematics, projectile motion, newton’s laws of motion, force diagrams, centripetal force, circular motion, conservation of energy and momentum, torque, angular momentum, oscillations, and gravity. During the second semester, we will explore a number of inter-related topics including: heat, thermometry, the laws of thermodynamics, electricity, magnetism, optics, electromagnetic induction, radiation, atomic theory, and nuclear physics.

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!

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 on a rotating schedule in WLHS 223—the science wing on the first floor of WLHS.

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

Registration for College Credit: Wisconsin Lutheran College is requiring students in this course who are interested in obtaining college credit. Please apply in the application link below for each class you are wishing to apply for college credit. This must be approved by Friday, September 27.

https://admissions.wlc.edu/register/foundations

Once students apply we will wait for Wisconsin Lutheran College to confirm eligibility and requirements for college credit and communicate out further information. Please reach out to Mr. Davis if you have any questions.

Teaching Assistant contact info: The Wednesday course sections (beginning in September) will be overseen by a teaching assistants. Alyssa Ebeling is an upper-level physics major at Wisconsin Lutheran College. Contact info: alyssa.ebeling[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/WLHS/

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. Late work will receive reduced credit.

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.