Conceptual Physics Summer Institute 2021: July 24-25, or July 31-Aug 1

All done for the conceptual physics institute in 2021!  I'll probably schedule another in summer 2022.  Do please let me know if you have a preferred weekend!  (Or if you'd be interested in something over winter break...) -- Greg

Folks, I'm already teaching several AP summer institutes - see the left-hand sidebar for details.  But what if you are looking for physics professional development that is NOT aimed at college-level physics?  I mean, I meet so many of you each year who teach on-level, honors, college-prep, Regents... to all ages, to all varieties of student.  And in my personal mission to spread physics knowledge to as wide an audience as possible, these sub-college courses represent a critical first point of contact with our discipline.  I focus as much energy on my conceptual course as on my AP course each year.  So I'd like to focus some of my summer professional development expertise on those who teach these first-level courses.

We did this last year, in 2020.  See the comments in this post for participant reviews.  They all say, this institute was an amazing, friendly, and productive experience.

I'm offering a two-day institute on July 24-25, or July 31-Aug 1.  These will be online, broadcasting via Zoom from my lab.  Skip past the institute description for fees and registration instructions.  Each weekend will be limited to the first 30 who sign up.  The daily agenda is included here at the bottom of the page.

Jacobs Physics

Conceptual Physics Institute Description
July 24-25 2021 or July 31-Aug 1 2021

All levels of high school physics can be taught conceptually – where verbal and experimental reasoning is prioritized over mathematical problem solving.  While mathematics are used extensively, they are used as a tool to create predictions about the workings of the natural world.  Whether you teach “general”, “on-level”, “honors”, “Regents”, or “college-prep” physics, a conceptual approach can be adapted to most any introductory physics topic – and to most any state or district standards. 

In our institute, we will discuss, practice, and share methods of teaching common physics content in a conceptual style.  I will be broadcasting from my laboratory via zoom.  Time will be devoted to experimental methods that are especially useful at the sub-college level; to course planning on a year-long and a unit basis; and to best-practices physics pedagogy, which differs substantially from pedagogy in other disciplines.

Participants will be given a full-year’s set of classroom-ready materials, including fact sheets, in-class and laboratory activities, assessments, and planning documents.  More importantly, through their interactions with the instructor and with their colleagues, participants will develop skills and ideas for adapting these materials to their specific classroom environment.  Those attending will also earn a certificate indicating their participation in 15 hours of physics professional development.

 

How much does it cost:  $200 for the weekend.  The schedule of events is listed below.

How do I register?
(1) Click the "donate" button below (or in the left column of the blog).  It will take you to paypal.
(2) Enter $200.00 as the donation amount, either through paypal or credit card
(3) Click "Add special instructions to seller" or "Add a note"
(4) In the note, please include your name, preferred contact email, and institution
(5) Fill in payment info and click "donate now"

That's all - I'll be back to you within a day or two confirming your registration, and sending you links to the classroom-ready materials.

Cancelation issues: If you register then can't attend, contact me via email.  As long as I can replace your spot, I'll send a full refund; if I can't replace your spot, I'll refund all but $25.

Schedule: Each session will include both whole-group presentation/discussion, and breakout groups for activities.  In between sessions and during breaks, Greg will be available for informal conversation. 

Saturday 24 July or 31 July (all times eastern time)

10:00                 Introductions

                        What does “conceptual” mean – defining levels of physics

Different levels of physics: developing your program

                        Different levels of physics: developing your resources

11:30               Eight styles of physics laboratory activities

            Including the two best-adapted for conceptual physics

My first day activity – reflection experiment

My first group laboratory experiment – refraction

1:00-1:30    break

1:30               Sequencing your course

Starting the year right: the most important physics teaching skill

Justifying answers with facts

Simple ray diagrams for optics in conceptual physics

Justifying answers with equations

In-class laboratory exercises: circuits

                       

3:00                 The daily “quiz”

Tests and quizzes, targeted to different levels

                        Other sorts of assessment

                        Preparing for the trimester/semester exam

                        Adapting a conceptual course to external standards

                        In-class laboratory exercises: motion graphs

Afternoon – asynchronous

                        Read through the shared files

                        Read through the Jacobs Physics blog

                        Adapt to your district or state standards

                        Bring questions and ideas for the social or for Sunday

7:30                 Optional Zoom social: Dinner, dessert, drinks, and conversation.  BYOB, obviously. 

Sunday 25 July or 1 August 

10:00                 Building and creating experiments with whatever you’ve got

                        Developing your own in-class lab exercises

                        Using or substituting inexpensive equipment

                        In-class laboratory exercises: direction of force and motion

11:30               Methods to speed your grading

                        In-class laboratory exercises: forces in 2-d

                        In-class laboratory exercises: motion in 2-d

                       

1:00-1:30    break

1:30               The final third of the year – once skills are built

                        How I teach impulse/momentum

                        Energy bar charts at the conceptual level      

                        Laboratory exercises with harmonic motion

                       

3:00                 Sharing: Any Other Demos

Online simulations:

                                    The Physics Classroom

The Physics Aviary

                                    Vernier’s Pivot Interactives

                        Ending the year: the Physics Fight

Dealing with g in conceptual physics - and a "false calculation" example

A correspondent has questions about how I deal with g in conceptual physics:

I notice that you intentionally use g as 10 N/kg instead of m/s/s and say that weight is the force of a planet.  I've noticed that when we get to energy, students struggle with g for GPE=mgh. They all want to put the mass (say 0.5 kg) but then they say 5N or 5N/kg for g.  It seems they have a very shallow understanding of what we're doing with 10 N/kg (and I notice you don't tell them explicitly to do mg for weight).  And the other thing they do is anytime they see a mass in kg, they'll "convert it to newtons." Or they'll see a force of 5 N and say it equals 0.5 kg.

Do you care whether they make the connection between "objects in free fall gain/lose 10m/s/s" and the gravitational field? For instance: when they're solving for speed based on KE, when N/kg doesn't fit with the other units. Or do you not really care about manipulating units, as long as they know what units go to what quantities (i.e. speed is always m/s, energy is always J).  

In conceptual, I don't care at all if they use careful language about g.  I never explicitly make the connection between the 10 m/s/s free fall acceleration and the 10 N/kg gravitational field.  They do need to put correct units on, of course... but I am fine with them "converting" 5 kg to 50 N.  As long as they sort of can get the correct values for weight and mass, I'm fine.  No unit manipulation ever.  

If they can do a calculation with mgh in a table, indicating correct units on m, g, and h, with J on the final answer, this is fantastic (and difficult for conceptual students).  At this point if they plug in numbers correctly in a table and get a unit wrong here and there, as long as the final units are right, I'm fine.  

Usually, I'm asking for a comparison between two situations, like "what happens to the potential energy of this 0.5 kg object when its height doubles?"  Here many students like to fall back on what they call a "false calculation" - plug in simple values to the formula for the first situation, then the second situation, and see how the results differ.  See below.  

Things to notice: 

* This student made the mass 1 kg to make the calculations easier.  I encourage that!  This is the conceptual physics version of "Bertha's Rule of Ones."  They chose 1 m and 2 m to double the height. If they had chosen 3 and 6 m, that's fine, too.

* I do expect units on their tables; I don't expect units on their arithmetic, because a lot of 14 year olds I teach have trouble multiplying (1 kg)*(10 N/kg), even though they can multiply (1)*(10) just fine.  Make the process simple, and likely to lead to the right answer.  

* Yeah, this student forgot units on g in the second table.  But they got 'em in the first.  I would likely let this go.  I mean, there's a line in the sand between doing math with no physics on one side, and pedantry on the other.  The goal is that by year's end, my students themselves should be uncomfortable if they left units off something.

What about in AP Physics?  I still start out not caring much about the true meaning of g... still no unit manipulation.  They do eventually need to understand that free fall g is the same as gravitational field g, because the AP exam discusses the difference between gravitational and inertial mass.  Yet, I don't even mention that difference or the connection until after spring break.  I'm far more concerned with their articulation of correct annotated energy bar charts; and with the conceptual difference between mass and weight.  (In AP, I do encourage students to write mg for the force of the earth on an object.)

You're right that student understanding of 10 N/kg is often quite shallow.  Usually they get it more as the year goes on; sometimes they don't truly "get it."  But if they can make proper energy bar carts and make correct qualitative and quantitative predictions with energy bar charts, then understanding the meaning of g can be left for a future class - or might never happen.  

Mail time: Sorting out the work done by a spring

The question asked of me, paraphrasing:

I gave my class a question on a test: a 20 kg object moves 4.0 m/s on a frictionless surface.  It hits a spring with k = 1280 N/m, which compresses 0.5 m.  How much work was done by the spring on the box?

The answer in the key is 160 J using W = delta K

The students used Wspring = Fspringdcos180  using Fs as 640 N, d is 0.5 m and they get 320 J.  Why are they not supposed to use this equation?

Or they use W = delta K + delta Us  and get 320 J.

What is going on?

The equation that work equals force times distance is ONLY valid when the force is constant.  In this case, the force of a spring is not constant - the force depends on the distance the spring is compressed.  So the student who used force times distance used an invalid equation.

The default for all questions about work should be to an energy bar chart.  Don't think about equations, think about an energy bar chart.

The first thought is to use the object-spring system: a system with a spring can have potential energy.  Then a quickly-sketched bar chart looks like 

The “Wext” column represents work done by an external force.  In this case, there’s no work done by a force external to the object-spring system!  The force of the spring on the object is internal to the object-spring system.  The normal force and the gravitational force act perpendicular to the motion so do no work.  So, writing bars + bars = bars – that is, considering energy conservation, the total energy initially plus the external work done on the system is equal to the final total energy – you’ll see that the 160 J of kinetic energy at first become 160 J of spring potential energy later.

Okay, that doesn’t help – you’re supposed to find the work done by the spring.  So do an energy bar chart for just the object by itself:

An object by itself cannot have potential energy.  PE comes from an interaction… just as gravitational PE requires earth to be part of the system you’re considering, spring potential energy requires the spring to be part of the system.  So here, kinetic energy is the only possible energy!  KE at the beginning disappears because the object comes to rest.  By bars + bars = bars, the amount of kinetic energy plus the work done by external forces must equal zero.  Since the object had 160 J of kinetic energy, the spring must do -160 J of work on the object.

It is true that the amount of work done by the spring is 160 J, and that’s also the same amount of potential energy stored in the spring-object system by (1/2)kx^2.  Yes!  But, you can’t consider both of these 160 J values separately.  EITHER you’re considering the object by itself, in which case potential energy doesn’t exist; OR you’re considering the object-spring together, in which case there’s no work done by an external force, only potential energy.

Each time you do an energy problem, define the system clearly.  Then use an energy bar chart.

Hope this helps!

Results: 14th Annual US Invitational Young Physicists Tournament

On Saturday January 30, the USIYPT happened online.  Our tournament is not the same on zoom as it is in person - but, nevertheless, eleven schools shared and discussed their solutions to these four problems (this link here gives more detail on the problems):

• Physics of the "chatter ring"
• Physics of the Lava Lamp
• Modeling impact craters
• Joseph Henry's rocking motor

After the preliminary rounds, The Nueva School of California was in front; they, Phillips Exeter Academy of New Hampshire, and Woodberry Forest School of Virginia made the final round.

Final round scores:

1. Phillips Exeter Academy, 174 points - CHAMPIONS
2. Woodberry Forest School, 173 points - SECOND PLACE
3. The Nueva School, 167 points - CLIFFORD SWARTZ TROPHY

All participating schools this year won the Bibilashvili Award for excellence in physics - this award is given each year at the tournament director's discretion, usually for those whose preliminary round score is above 100.  This year, with the unusual online format, and knowing that just showing up at all represented a major accomplishment in the pandemic times, the tournament director decided that all schools earned this prize.

Bibilashvili Award winning schools:

• Cary Academy, North Carolina
• Rye Country Day School, New York
• Phillips Andover Academy, Massachusetts
• The Harker School, California
• Shenzhen Middle School, China
• Vanke Meisha Academy, China
• Qingdao No. 2 High School, China
• Episcopal High School, Virginia

Big thanks to tournament director Tengiz Bibilashvili of UC Santa Barbara, and to Chief Juror Peter Sheldon of Randolph College, for leading the logistics of what proved to be a long but very fun day.  I can't here thank each of the 24 jurors and 11 team leaders... but thank you nonetheless!

Want to get involved?   If you're looking for a venue for your strongest physics students to share their research, this is the place to go.  The tournament is competitive, of course, yet we steadfastly maintain a culture of cooperation and camaraderie.  Our goal is the Search for Nature's Truth.  Contact me via email.  I'd suggest coming next year as a juror; then, when you're ready, prepare and bring a team!

The 2022 tournament will be - hopefully - at The Science House at North Carolina State University next January.  Dates and final site logistics will be posted at the USAYPT website this summer - once we can plan for the future again.  

Problems for 2022 are available here - even if you don't come to the tournament, these are excellent advanced high school or undergraduate physics research questions.

And here is the updated list of all teams who have participated in our tournament since its inception in 2007.  As of 2021, Exeter joins The Harker School as three-time champions.