141 Fall 2019 Week 1

Units: distance (meters), speed (meters/second), or speed is the time derivative of distance: v=dx/dt, Force (Newtons)
Before Class:
!!! I’ve just posted office hours for myself and Dr. Klay on the main class website.
  1.  Please note my office hours have been posted on the main class website. Please check them and decide which ones you may visit.
  2. View Position and Velocity 
  3. Watch Veritassium video, Say the Wrong Thing
  4. Read more about confusion on NPR: Confusion is How it Feels to Learn
  5. Read the paper I published about our learning method in The Physics Teacher. Figure out if this is going to work for you.
  6. Read the following in the textbook (link on main class website).
    • 1.1 Momentum
    • 1.2 Energy
    • 1.3 Dynamics
    • 1.4 Kinematics  
  7. Finish Problem Set #1

 During class:
We look at a collision on an (almost) frictionless surface. Momentum and energy are conserved in a closed system. However, can momentum or energy change forms?
Hand in Homework #1

After Class:
Consider the cart collision today in class:
1) Is momentum conserved? How do you know?… Or don’t you know?
2) Is energy conserved? How do you know?… Or don’t you know?
3) Are there forces and accelerations? Please describe directions and magnitudes (how big they are)!
4) What about motion? Can you make a speed vs time graph for each cart? Can you make a position vs time graph for each cart?

Tuesday: First Assessment
We are learning to be conscious of the lens (concept) we are looking through or if we are not using a lens. We are practicing using the four different lenses.

Before Class:

Hi everyone. I wonder if you left class Monday with a disturbing feeling of incompleteness… in how we left so many loose ends. I myself sometimes get the feeling I did a crappy job as the “teacher” because I didn’t tie everything together. And then I REALIZED that my judgement was from my old education model. I mean wow… we just covered the first ~ 5 units from a regular physics curriculum in two classes. Of course we didn’t comprehensively tie everything together. When I look at what we did accomplish and talk about, I find it impressive. So if you’re confused… great! we will be going over this for the next several weeks. Hang onto those questions, bring them into class and we’ll pick this problem up tomorrow, and move onto the next demo (see “In Class” below).

  1. Solutions to PS#1 posted
  2. Please read through PS #2, posted on main class website 
  3. View Energy Flows 
  4. View Dropping Rock.
  5. View Acceleration Video . 
  6. Please see this video about estimating the speed of rockets
  7. Please consider this scientific study about learning. You can read the whole thing if you like, but certainly read the significance:
    “Despite active learning being recognized as a superior method of instruction in the classroom, a major recent survey found that most college STEM instructors still choose traditional teaching methods. This article addresses the long-standing question of why students and faculty remain resistant to active learning. Comparing passive lectures with active learning using a randomized experimental approach and identical course materials, we find that students in the active classroom learn more, but they feel like they learn less. We show that this negative correlation is caused in part by the increased cognitive effort required during active learning. Faculty who adopt active learning are encouraged to intervene and address this misperception, and we describe a successful example of such an intervention.”
  8. Please read in the Textbook (link on main class website):
  • Energy, please review the energy chapter: 1.2,
  • 1.5 Acceleration
  • 1.6 Potential and Kinetic Energy

In Class:
After the first assessment, we will look at roller coasters on different tracks falling and compare times to fall and speed at the end. The goal is to practice using the 4 different concepts and recognize that we are reluctant to use these lenses. Instead of invoking the new tools we are introduced to, we often revert to methods of reasoning that we have used before! The goal is to increase our awareness that we do that!… and start developing new tools. Can we examine our inherent familiarity with how physics works in nature; Can we close our eyes and “see” what will happen?

While taking assessments, we can develop an understanding of how we can manage our feelings and approach. In order to prepare for it, please consider this paragraph in the paper I wrote about our learning model:

…students in this class did not start questions with lens identification until after the grading policy was invoked. Even with full knowledge of the rubric and practice in class, the vast majority of the students (and two instructors sitting in on the class) did not identify a lens on the first quiz and thus received a grade of D. Subsequently, most students consistently began answering each question identifying the relevant concepts. It is possible that the change in grading alone would have resulted in students beginning each question with concept identification. Accordingly, a recent publication reports increased student learning with ungraded, timely feed- back and other Formative Assessment techniques.1

  1. J. Haugan, M. Lysebo, P. Lauvas, “Mandatory coursework as- signments can be, and should be eliminated!” Eur. J. of Engin. Educ., 1–14, March 21, 2017; published online at http://dx.doi. org/10.1080/03043797.2017.1301383


Before Class:
-1. See solutions to PS #1 posted.
0. Please identify and do a few questions from PS#2 posted on main class website. 
1. View Forces Effect on p, v, E
2. View Scaling
3. Elon Musk just uses simple scaling to create disruptive technologies: Quartz Media Story
4. Read about in the text available on main class website:

  • 1.7 Forces, Momentum, Energy
  • 1.8 Applying Lenses of Mechanics
  • 1.9 Scaling – How does behavior change as things get bigger?

During class:


Before Class
What if you want to see a video the second time and also want to see the questions? Just click on the small vertical bars at the bottom of the video that indicate where the questions are located in the video.

  1. Roller Coaster Demo: So, we developed a physical model to explain what we predicted would happen when I let the balls go. The balls all went about the same distance before hitting the ground, and the blue track finished before the red track, by a considerable amount of time. Please address what was correct or incorrect about your original model. Please develop a new model to explain what you saw.
  2. Do PS #2… as much as you can. It is due Monday in class!
  3. View Pushing Box Problem.
  4. View this 3 minute video : Energy, Work, and Power. Be prepared to answer this question: a 1000 kg car starts from rest and accelerates to 30 m/s in 5 seconds. Please calculate the average power the car produces to do this. Please put answer in Watts and Horsepower.
  5. Read in the textbook
    • 2.0 Forces and Work
    • 2.1 Power
    • 2.2 Units

During Class
Prepare for your activity next Tuesday: You will make a video and calculate the kinematics, energy, Power, momentum. This assignment is to be handed in next Thursday.

After Class:
FRIDAY: Take part in the climate rally at the court house… even better, join the bike swarm:
There are plans shaping up for a mass bike ride – a swarm of bicycles,
The bike swarm will leave from in front of Kennedy Library at 4:45pm this Friday September 27.

Videos I find helpful
Veritasium’s Cool Science Home