Back to Main Class Website

Vectors in the four lenses. Also, proving energy formulas.

Before Class
  • Two videos describing the role of vectors: Vectors: Forces, momentum, Vectors: Energy and Kinematics
  • See video on Proving why the kinetic energy formula is correct.
  • Also, see the video about Doc Edgerton's Photograph of Denny Shute hitting the golf ball
  • Read section 2.4 (Vectors and Direction)
  • Complete your project from Thursday. Come to class with questions.
  • We will meet in Baker Science, 180-262 where we used the computers Thursday. We will meet here again Monday because I think people may want to use the computers again. We will not make this our regular room. We will return to 53-201 tomorrow, Tuesday.
  • I have your graded PS#1 and I posted the solutions. I have the following to report:
    • I spent a long time on extensive solutions, I encourage you to read through them because...
    • The grader didn't mark everything wrong that was wrong, so you really need to look at the solutions to see what you missed.
    • In general, there were not enough drawings!!! Please make a drawing for (almost) all the problems.
  • Check out PS #3 posted on main class website.

During Class
  • MEET in 180-262 where we used the computers on Thursday!
  • So ends two weeks of 141. How is your experience so far?
  • Work on your project. Finish it up!

Tuesday: We will explore more complicated dynamics problems: the elevator problem.

Before Class
  • The Elevator Dynamics Problem
  • Please see this video demonstrating the dynamics protocol.
  • Bozeman Science FBDs
  • Read 2.5 (Dynamics)
  • Take this 10-question conceptual physics survey. There will be 4 more. I expect that everyone will do all do them and we will review the results in class to learn as much as possible. Full disclosure: It really has 13 questions including your name.
  • Solve this problem as part of PS #3. Come in tomorrow with questions if you don't follow what to do.
  • PS#2 solutions posted. Please see on main class page.
  • I read through your feedback and responded to a few of them. Please see the complete student statements - link on the main class website.
  • Meet in regular room: 53-201.

During Class
  • Meet in regular classroom, 53-201
  • Big Exam #2 Be ready to demonstrate perfect dynamics protocol.
  • How do you keep the water in the bottom of the bucket?
  • A string breaks

After Class:
Would you like to have a garden, or learn about aquaponics, growing mushrooms? Bee keeping? Tree nursery? Please consider coming to the
Student Experimental Farm this Sunday at 11 AM, or thereabouts. How do I get to the SEF?

Optional video: Veritasium on how they measured gravity waves. 2017 Nobel Physics Prize!

Wednesday: Springs and Review

Before Class
  • I posted your feedback statements on the main class webpage
  • Make sure you've read through PS #3
  • PS#2 solutions posted. Please see on main class page.
  • See video about: Springs!
  • Potential Energy Graphs video
  • Some physical work I did at home
  • See Student Project Video: Measuring Speed of Bullet
  • Read 2.6 Springs
  • Read 2.7 Energy Graphs
  • Read 2.8, a review about the lens method, updated to include vectors
  • Important to consider for today's class... your life may depend on it. You have two balls to throw against a door in order to close the door with the impact of the ball. One ball is perfectly elastic, and the other one is perfectly inelastic. Which ball will be most effective at closing the door? Why?

During Class
  • a string breaks.
  • Surviving a fire in your dorm room


Before Class
  • Finish Project #1
  • See: Elastic Collisions with Walter Lewin at MIT
  • Read 3.0, Changing Reference frames and then, see the video below.
  • Elastic Collisions with Pete at Cal Poly by Changing Reference Frames This is my most popular video - after ~ 4 years, it has over 22,000 views. See if you can tell me why it's the most popular of my videos.
  • Read 3.1, elastic collision in 1 dimension.
  • If you like, please check out 8.4 from the original OpenStax textbook to see how the rest of the world looks at elastic collisions in 1-Dimension using simultaneous equations. Please reflect on the following two questions
    • How do you compare this chapter to the chapters that I write?
    • How do you compare this method to the picture drawing method that I present in the video?
  • See Firehose Video
  • Optional reading on NPR about active learning in Physics Education Research. The author, Carl Weiman who won the Nobel Prize in Physics for Bose Einstein Condensation gave a talk at Cal Poly some 12 years ago calling on us to evaluate and innovate teaching with the same scientific process we use for other scientific research. Since then, he’s become prominent in Physics Education Research. He’s published a considerable amount about active learning strategies and over the years has become more outspoken about the futility of the lecture model and need to change.
  • Another NPR article about education:
    • "The first step is to teach Socratically, by asking questions and having students think out loud. This works much better than lecturing."
    • "Teachers who find their kids' ideas fascinating are just better teachers than teachers who find the subject matter fascinating,"

During Class
Hand in Project #1
Elastic Collisions