## Tuesday, November 24, 2020

### Inertia is how much, not if

Hello Blog of Phyz world! I wrote a piece for the Talkin' Physics column in The Physics Teacher's December 2020 issue. In the interest of sharing it more widely and outside of a paywall, below is the blog-ified version of that article. You can also find a pre-print PDF linked here.

Inertia is an elusive concept in physics, and it is occasionally used to explain similar-seeming yet different concepts. The goal of this article is describe two scenarios which are commonly explained using the word inertia, even though that same word is being used to describe two different phenomena. A discussion clearing up this ambiguity follows the examples.

Consider a block of frictionless ice in the bed of a flatbed truck, as seen in the figure below. If this truck begins to accelerate from rest, the ice will remain stationary with respect to the ground and eventually fall off the back end of the truck. Why does this happen?

Next, consider the two blocks on horizontal frictionless surfaces shown below. Ropes pull them both to the right with 10 N of tension force. Block A mass a mass of 1 kg, while block B has a mass of 5 kg. Which one has a greater acceleration, and why?

Inertia is often invoked to explain both of these examples. In the first, the frictionless ice block maintains its state of rest of because of its inertia. In the second, block B has a smaller acceleration because it has more inertia than block A.

The theme song for Bill Nye the Science Guy famously states that “inertia is a property of matter.” If we accept this Bill Nye maxim, then only the second example is truly a demonstration of the idea of inertia. The frictionless ice of the first example does not remain at rest relative to the ground because of any intrinsic property it has. Rather it stays at rest because of its lack of net interactions with other objects around it. The first example illustrates how matter behaves when interacting or not interacting with other objects, but it does not illustrate any property that matter has. In the second example, Block A accelerates more than Block B because of a property intrinsic to each block.

Similarly, Donald Simanek argues that most so called “inertia demonstrations” would better be classified impulse demonstrations. On the topic of the classic tablecloth pull demonstration, Simanek writes that, after viewing the demonstration, “The audience didn't see anything that showed that objects with different inertia (mass) behaved differently.” Instead, they saw that you could reduce the impulse delivered to plates by reducing the amount of contact time the plates have with the tablecloth. Again, we see a demonstration of matter’s behavior when interacting with other objects and not a demonstration of something intrinsic to matter itself.

In this view, inertia is a property that says “how much” rather than “if.” It does not say whether an acceleration will happen, but rather how much acceleration will happen for a given net force. For example, an object having an inertial mass of 5 kg means that, for every additional 1 m/s/s you want the object to accelerate, you will need to exert an additional 5 N of force. This is what we mean when we say that mass is a measure of inertia. It does not mean that it is five times better at maintaining a constant velocity than a 1 kg object. Both would be equally good at doing that if there is a net zero force acting on those objects, and both would be unable to do so if there were a net force exerted on them.

Perhaps, to bridge the gap between the two demonstrations, we may want to say that the intrinsic property inertia measures how little an object deviates from its inertial path when a given net force is exerted on the object. We could modify our frictionless ice in the truck example to demonstrate this idea. To do so, we would need to replace our frictionless ice with regular, boring ice with friction, so that there is a nonzero net force on it when the truck accelerates forward. We would also need to have two blocks of ice of different masses so that we could compare how much one deviated from its rest position relative to the other for a given friction force. Doing so would allow us to demonstrate than an object with more inertial mass deviates less from its inertial path than object with less inertial mass when the same force is applied to each. Inertia is a comparison of how much, not if.

Similarly, the tablecloth demonstration could be amended to be a true demonstration of inertia. It is not enough to pull a tablecloth out from underneath a ceramic plate to call it an inertia demonstration. If you instead pulled a tablecloth from underneath both ceramic and paper plates and compared the accelerations of each, then you would have a great demonstration of the property inertia. Both plates accelerated, but one acceleration more. Why? Because the plates’ inertias differ. In this example, we are not saying that the ceramic plate remains stationary. Instead, we are saying that its change in velocity is less than the change in velocity of the paper plate. The emphasis is on the amount of change, not on whether or not change occurs.

In the end, it may be time to retire the word inertia altogether. Many physics teachers are comfortable requiring students to refine statements around gravity, asking them to “upgrade” their language from saying gravity alone to saying gravitational force, gravitational field strength, or acceleration due to gravity. Similarly, ambiguity surrounding inertia can be avoiding if we choose language that is more specific.

For example, one could say that Newton’s first law describes an object’s inertial behavior or the inertial path it may follow. These are not intrinsic properties of matter, but rather descriptions of how interactions affect what matter does. Inertia, in this sense, cannot be quantified. Newton’s second law, on the other hand, describes an object’s inertial mass—its resistance to acceleration. The inertial mass described in Newton’s Second Law is an intrinsic property of matter, and it can be quantified.

Like gravity, inertia is a broad and overarching concept. Saying an object has the property inertia is less clear than saying it has inertial mass. Saying an object moves at a constant velocity because of its inertia is less clear than saying it follows its inertial path or it is exhibiting inertial behavior. By improving our language, inertia can be both “how much” and “if.” We simply need to clarify which we are using and acknowledge that they are not the same.

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in The Physics Teacher 58, 682 (2020) and may be found at https://doi.org/10.1119/10.0002746

## Wednesday, November 18, 2020

### RT;DL Things That Go Bump!

Which involves more force: stopping or bouncing? Let's demonstrate.

I inherited a stop/bounce dart when I arrived at my school in 1986. You arrange the dart as a pendulum and swing it into a wood block. Back in those days, you ran the unadorned nail point into the block for the stop, and attached a rubber stopped to the nail point for the bounce.

Since then, the advent of "happy" and "sad" balls improved this demo. And happy/sad pendula/mallets have been commercially available (help me out with a link if you know one).

Arrange the dart so that it barely knocks over the block using the happy ball on the tip. Then switch to the sad ball and allow for predictions and arguments. Then proceed with the reveal.

## Sunday, October 25, 2020

### A new letter grade for the pandemic: E

It is impossible to characterize everyone's experience with teaching and learning during the COVID-19 pandemic spread throughout the world by the novel coronavirus.

Many teachers are working with unprecedented intensity to craft synchronous and asynchronous instruction that will cover and deliver academic content in an engaging and suitably rigorous way.

But the products of all this time, talent, and energy are not being universally absorbed by the students in the black Zoom thumbnails with muted microphones. There are stories in each one of those blank frames, covering a broad array of situations.

Many of us seem to have students who are completely disengaged. They are on our rosters, but we never see them, they are not in our Zooms, and they do not turn in assignments or take assessments. They rapidly descend into grades that are in the single digits, perhaps up to about 20%.

But there are some who seem to be somewhat engaged. But their participation is scattershot. They fall below 60%, but remain north of 40%. I am wondering if an F is the best grade for them while schools are wholly shut down or (worse), engaged in the pure partial daycare service that goes by the name of "hybrid".

So what about a grade of "E" for them? Not an "F" grade of fail. But not really a "D", either. "E" for evidence of engagement.

As a practical matter, the best I can do for now is to expand my range for a "D–".

One thing that a number of us are seeing more and more of in our parent-teacher conferences is parents and students who want to take an F for this semester so that they can repeat the course for a better grade next I'm not a fan of that practice. [Side note: Physics and Conceptual Physics are scheduled to be replaced by Physics of the Universe in my district next year, so that practice will be messy.]

I would let students move on with Es. Otherwise there will be a pandemic of students wanting to repeat courses when schools reopen in a meaningful way.

It's just an idea for now. But I wonder if it's an idea that will make more and more sense the deeper we get into the pandemic.

What do you think?

### RT;DL Thermoscope

I was reluctant to post this since thermal physics has been so thoroughly abandoned by NGSS (HSPS) and AP Physics. And also because the apparatus that I use appears to be unavailable. And the ones I was able to get most recently are a bit fiddly to use.

But what the heck? Physics teachers teach across a spectrum and not everyone is beholden to NGSS and AP. And physics teachers are a resourceful bunch: There may be other ways to do this without the exact apparatus I'm using here.

The demonstration revolves around what I've been told is a Galilean thermoscope. A narrow-throated Florence flask is used here, as is a beaker, some food coloring, a twist-tie, a blow drier, a hot plate, and some water.

I like it enough to continue using in in my AP Physics 2 unit on thermal physics which is a pre-cursor to the unit on thermodynamics.

An instant Zoom poll using participant reactions is once again included.

HTML Presentation - Thermoscope (includes animations and live-action video)

If you have a clever workaround to get past the dearth of what were once sold by Sargent-Welch as "air bulb thermometers," let me know in the comments.

## Sunday, October 11, 2020

### My district bans a Jewish surname...

...from emails sent to district-managed student accounts. Here's the story:

In COVID-era Distance Learning, I have found Socrative to be a useful platform for administering student assessments. Among its useful features is the ability to send students their own individual scored test, showing which questions they answered correctly and which ones they answered incorrectly. The results can be sent to student email accounts with the push of a button. [You are correct to assume the instructor had to enter those email addresses into Socrative. But it's a one-time investment.]

This is a great feature for when we do Test Correction Journals.

But in my very first attempt to leverage this feature, it failed. I had, of course, tested the feature before using it with students. And it worked. But when I sent my students their test results, students insisted they did not receive them. I tried it using Chrome, I tried it using Firefox. Nothing worked. I had to create a privacy-respecting, individualized way to tell students which specific test items they missed. I created one breakout room per student, joined each one—one at a time, and announced which items they missed. While class time was burning.

I quickly came up with a functional workaround for the next period, but it fell short of what I needed it to do. And why didn't the student email solution work?

Students suggested that the district blocks third party emails from student accounts. The vendor, Socrative, meets all legal privacy standards. District tech services said they do not block third parties. Further investigation indicated the emails were blocked because they contained objectionable content. That offensive content appeared in the following question. TW: "Objectionable Content."

[Secrets of the Psychics] Psychologist and former palm-reader Ray Hyman found that he had the greatest success with clients when he

B. told clients the opposite of what he saw in their palms

C. imagined that he lived in an earlier era

D. assumed his clients were skeptical of palm-reading and his abilities

There it is: the objectionable content, clear as day. What's that? You didn't see it? Look again. "hymen" is right in there. Prurient anatomical terminology titillation that would offend any community's standards of propriety. High school students must be protected from such filth.

Okay, not "hymen" exactly, but "hyman," a simple misspelling of a highly salacious, practically pornographic word. Okay, not "hymen" or "hyman" exactly, but "Hyman," a not uncommon Jewish surname. I presume my college hall mate's name, Steve Hayman would trigger that comprehensive filter, too, lest bad actors use simple misspellings to skirt content filters.

Some might judge the content filtering of Jewish surnames (that are not anatomical terms) as anti-semitic. I'm confident the San Juan Unified School District doesn't intend it that way, but here we are. "Ray Hyman" triggered a full and immediate IP ban due to the district's sweeping content blocking protocols.

I was given no reason to hope that this filter would be removed by my district's tech services, now that they are aware of the embarrassing error. It seemed as if the onus was on me not to include terms that would trigger bans, and I should just know what all those terms are.

The filtering is clearly far too aggressive and highly impractical. Blocking my instructional program (without notification) for the "crime" of including a Jewish scholar's name? That's beyond a bad look.

It's indefensibly paranoid and ignorant, in my assessment.

UPDATE: This is apparently just another instance of The Scunthorpe Problem, or as Tom Scott calls it, The Peniston Problem.

## Saturday, October 10, 2020

### RT;DL The Tower of Bottle

In the pre-blog, pre-social media days of the mid-1990s, when the World Wide Web was Alien-birthing from nothing (1994) to everything (1995), I was involved with the Southern California Alliance of Mentors for Physics Instruction and its Southern California Area Modern Physics Institute. Yes, two SCAMPIs in one. John Jewett (Cal Poly Pomona) and Roger Nanes (CSU Fullerton) outdid themselves on the acronyms!

Somebody at the California Department of Education liked what SCAMPI was doing, and wanted to get four Northern California teachers involved. I was chosen/selected to be one of them. Jessica Downing, then the Science Department at Esparto High School (now IB coordinator at Inderkum/Natomas) was selected as well. She and I conducted SCAMPI workshops throughout Northern California during those years.

I got this demo idea from her.

The gist is to show that the molecules in a jar of hot water are moving faster than the molecules in a jar of cold water. Just add food color and wait a minute.

But while we're here, let's add some value. Lay a playing card on top of the hot water and flip the bottle over. The card stays in place and the water doesn't spill.

Set the bottle mouth down on the cold bottle and remove the card. The result is surprising.

Then re-insert the (a) card and flip the configuration over so that the cold water's on the top. Remove the card. And it's a different outcome.

Last, a few questions of balance or imbalance. If you were nervous that I wouldn't shoehorn a Zoom participant reaction poll in, ease your worried mind.

Google Doc: Demo - The Tower of Bottle

HTML Preso: Demo - The Tower of Bottle

Single-shot video of the complete demo

Enjoy!

## Thursday, October 08, 2020

### RT;DL Blowout—Newton's Laws Edition

My use of Pasco's Lenz's Law demonstrator as a blowgun to explore the equations of motion is discussed in a previous post. That's an activity I don't do in my regular Physics class, because number puzzles aren't a priority there.

In this activity, I introduce the blowgun to Physics, do a quick speed determination, and then detail how Newton's laws of motion apply to the various portions of the Hero's Marker's Journey.

How are Newton's third, first, and second laws relevant to when the marker (bullet) was in the tube (barrel)? Between the barrel and the box? When caught by the catch box?

I do this after all three laws have been taught in class. It's a nice review.

For example, when the marker is in the tube, Newton's third law is relevant in that the air pushes the marker forward while the marker pushes the air backward.

Newton's first law is relevant in that the marker at rest would have remained at rest, but was acted on by an unbalanced, external force applied by the air.

And Newton's second law tells us the acceleration of the marker will be proportional to the force that the air applies and inversely proportional to the mass of the marker.

In the end, we ponder how to make a faster-moving bullet based on Newton's laws. I can't blow any harder. So we modify the bullet.

Is this demonstration activity really just an excuse to do another blowgun activity in class? I mean... what are you even talking about right now? That's ridiculous! Why would you even suggest such a thing?

It really is a nice review of Newton's laws.

Google Doc: Demo - Blowout (Newton)

HTML Preso: Demo - Blowout (Newton)

Enjoy!

## Monday, October 05, 2020

### RT;DL The Newtonian Shot

I'm embarrassed to confess that I don't remember the name of the physics teacher who shared this demo at the January 1986 MSTA Meeting in Lansing. I do recall driving past many cars that had slid into the ditch on the road from Ann Arbor that morning. It was windy and icy. And cold.

But the demo stayed with me, and I worked it into my curriculum early on. It was my first Show & Tell at an NCNAAPT Meeting (Spring 1992, American River College, IIRC).

I think it's a great demo for the Newton's Law unit. There have been times when securing toy dart guns was a challenge. They can last for many cycles, but they were built as inexpensive toys, not precision science apparatus. Fortunately, Arbor Scientific has become a reliable source

I wrote a post about this demo previously, when I recorded some nice high-speed video of it. It includes a few more specifics.

Here's the RT;DL stuff:

Google Doc: Demo - The Newtonian Shot

HTML Preso: Demo - The Newtonian Shot (including convenient Zoom participant reaction instant poll)

As ever, my presos are designed to support my storytelling and do not stand on their own terribly well. (Like a backup band with no lead singer.) And you can see I use aluminum support rods to help with the simultaneous launch. I launch the darts from ceiling-level down to my countertop so students can see the landing point. I protect my concrete countertop with a wood plank.

## Monday, September 28, 2020

### RT;DL Cannonball - Ball dropped from moving ship

Another classic demo that can elicit excellent classroom discussion. A cannonball is dropped from the mast of a moving boat. Where will the ball land? This nicely confronts our inner Aristotle.

In my version, the premise is laid out, the landing point options are described, and students are asked to produce arguments supporting three of the five possible landing sites: one that they believe, and two they could convince others of (as good attorneys).

A straw poll is conducted (now with Zoom participant reactions), then students are asked to defend their various positions. After the classroom discussion/debate, a final vote is taken.

I warn them to vote carefully. "Physics is a democracy, and whichever outcome gets the most votes will  be correct. The universe will accede to our wishes. Please vote responsibly!"

Then we see the actual outcome. First in my animation; eventually in the classic Project Physics footage from 1968. In face-to-face instruction, I also carry it out using a discontinued Pasco product (Ballistic Cart Accessory with Ball Drop Attachment). So sad to see that combo go.

Lastly, I ask students how the demo could be altered so that the ball would land at the other locations that were offered in the premise. The 1968 footage shows one such modification. I leave it to students to think of the others.

Student sheet: Demo - Cannonball

HTML Preso: Demo - Cannonball

The HTML export from Apple Keynote had a few wee quirks this time. Mostly in that while most of the splash sounds are muted, the audio from the 1968 video (muted in my preso) comes through loud and clear in the export.

## Sunday, September 27, 2020

### RT;DL The Clever Dumbbell - Tension & Inertia Demo

A classic and popular demo. I do it in Conceptual Physics, Physics, and AP Physics 1. And I use a 5-lb dumbbell and kite/packaging cotton string. For years, I used a cast-iron dumbbell. But I broke floor tiles on occasion, and there was that one time the wheel-like nature of the dumbbell ends allowed it to roll onto a student's open ... toes. So I found rubberized hexagonal-end dumbbells. And I use a cardboard catch-box with scrap paper to protect the tiles.

After posing the initial question: Which string will break when the bottom string is pulled, I have them work through some leading questions.

Instead of having students predict which string will break, I have them request a string for me to break. Once they understand this paradigm shift, they request the bottom string. And I oblige. Eventually I break the top string, too. This can be navigated in the preso, alone. But I prefer to do the demo in my empty classroom because I can.

The efficacy of this demo lies in the dependence of the outcome on the presenter's technique. If it were a 50-50 coin flip each time, the demo would not have any pedagogical value. Some ponderables are offered post-demo, too.

As is a continuing theme in my RT;DLs, the student sheet is a Google Doc and the preso is an Apple Keynote preso, exported to HTML. These exports work delightfully on computers. Not so well on tablets or phones.

This one takes a bit of practice to navigate.

Things shown in images but not in words: strings break when they are stretched beyond their limit by tension greater than the sting can withstand. A rapid pull stretches the bottom string through its limit before the dumbbell moves very much, thus keeping the top string from being stretched. A slow pull allows the top string to be at greater tension than the bottom string, allowing it to reach its limit before the bottom string does.

Student sheet: Demo - The Clever Dumbbell

HTML Preso: Demo - The Clever Dumbbell

## Saturday, September 26, 2020

### RT;DL Blowout: A tour through the equations of motion

Near the close of the last century, I wrote an article for The Physics Teacher extolling the unadvertised virtues of Pasco's Lenz's Law Demonstration tube.

Sure, you could use it to demonstrate Lenz's law, but that fine aluminum tube seemed pricey, so I was keen to justify the expense. You can tap it with a mallet (or on the ground) while holding it at various places to produce different notes. The Q of aluminum is great for this. You can stand it up on its end in your classroom to demonstrate unstable equilibrium.

But for my notion of classroom theatrics, the best unintended use for the tube was as a blowgun.

For this RT;DL I prepared a tour through the equations of motion with the blowgun acting as my vehicle. it is very much up to the task. I do this in my AP Physics 1 course only. Regular Physics students don't really need the exercise in number puzzles that the equations of motion afford. The year's too short.

In any case, I blow a marker pen through the tube and arrange two photogates near the muzzle to help determine the exit speed. It's over 60 mph!

Once the exit speed is determined, we figure out the acceleration of the marker while it was in the tube. Over 20 g's.

We also figure out how long it took the marker to exit the tube once its motion began. Then we investigate where the marker was when it was at the half way point (in time) along its journey through the tube.

The preso is enhanced with photos and high-speed videos. And an instructive(?) blooper at the end.

HTML Instructor Preso: Demo - Blowout

HTML Student Lesson Companion: Demo - Blowout [Instead of worked out solutions, "Show that..." prompts are provided.]

Exploratorium friends, Don Rathjen and the late Paul Doherty, turned the blowgun idea into a nice Snack: Marshmallow Puff Tube.

## Wednesday, September 23, 2020

### RT;DL The Great Bullet Race

I run this demo in AP Physics 1. I don't run it in Physics. Why? Projectiles is not a topic I teach in Physics. We tend to spend more time in kinematics than kinematics is due. It wasn't a big topic in California Science Standards Physics (RIP). It's not that big a deal in AP Physics 1. It's virtually non-existent in NGSS Physics. If you are among the few, the happy few—the band of brothers and sisters—who teach a year-long AP Physics C-Mechanics, have at it!

But physics teachers of all stripes love, embrace, and perhaps cling to our kinematics. Maybe after a decade of NGSS Physics and a generation of retirements, kinematics' star will begin to fade. I have my doubts. Kinematophilia seems to have inordinate inertia. </soapbox>

In any case, we still regard this demo as a classic. [We don't seem to have a universally agreed-upon name for it. Or if we do, I don't know what it is.] So when it came up this year, I spent some time in my empty classroom trying to get some useable high-speed footage.

Here's the student sheet and preso I cobbled together. (The Mythbusters segment is included.) Oh, and where a prediction is called for, Zoom participant reactions are solicited (yes, no, go slower, etc.).

Google Doc: Demo - The Great Bullet Race

HTML Presentation: Demo - The Great Bullet Race

I found the embedded videos in this HTML export to be a bit cantankerous—practice before using in class. Arrow keys to advance. Clicking in a video activates a scrub bar at the bottom and allows you to scrub forward/backward in that video.

Maybe you can get some use out of these; maybe your district won't let you use it. Guns and bullets are discussed, modeled, and used.

[RT;DL is remote teaching; distance learning]

## Tuesday, September 22, 2020

### RT;DL Inertia in Action

[RT;DL is remote teaching; distance learning. Where we show our attempts to bring extant lessons into the COVID-19 era.]

In the old days of face-to-face, in-class teaching, we did a station lab activity involving inertia experiences. It was called "Inertia in Action."

I retooled it into a video-based demo in which small groups could view segments, discuss prompts, and record their ideas on a Google Doc. It may not be your cuppa. But it works for me, given the circumstances.

The Google Doc is here: Demo - Inertia in Action.

The HTML export of my Keynote press is here: Demo - Inertia in Action. This is nice because to can advance it at your own pace. But it has trouble on phones and tables, so...

A video of the presentation is posted to YouTube: Demo - Inertia in Action. More compatible, but viewers must stop and start the video on their own.

Here's the video. It doesn't make much sense without the prompts.

## Saturday, September 19, 2020

### Physics with Dianna

Learn physics from Physics Girl, Dianna Cowern.

If you really want to lecture over Zoom this year, godspeed. If you'd rather do ... anything else with your synchronous time, let Dianna nail down the basics for you. Feel free to supplement to your heart's content. But I'm confident Dianna can handle intro exposition more effectively than I can. This is what she does.

# Dianna's Intro Physics Class: Trailer - Physics 101, AP Physics 1 Review with Physics Girl

Never taken physics before? Want to learn the basics of physics? Need an AP Physics 1 review before the exam? This course is for you!
In this class we will cover these topics:
1D Motion
Free Fall
2D Motion
Newton’s Laws
Free Body Diagrams
Friction
Circular Motion
Gravity & Orbits
Energy & Work
Energy Conservation
Power
Momentum
Impulse
Collisions
Rotation
Angular Momentum
Simple Harmonic Oscillations
Waves
Sound
Electric Charge
DC Circuits

## Monday, September 07, 2020

### The Lessons of Phyz September 2020 update

When the pandemic closed the schools, I scrambled like most teachers. Our worlds had been thrown upside down and there was an expectation that we'd simply "throw our lessons online," hold classes on Zoom, create YouTube channels of our lessons, etc., and leverage the best among the countless sophisticated online platforms intended to allow our instructional visions to flourish while engage students completely.

Yeah...no.

More like an old desert-dweller suddenly cast into a roiling ocean while helicopters flew by and dropped materials that, when properly constructed, would make a nice boat. Or... we were expected to build the plane while it was in flight.

In any case, I found that the simple task of assigning a video for students to watch while answering questions was suddenly a challenge. Things worked better if the question sets were in Google Docs format. I could easily assign them and grade them (if need be) in Google Classroom. Many had been in PDF format: not edit-friendly for student work.

So I began the tedious task of transforming my video question sets from their PDF or Word formats to Google Docs. When I finished the ones I was in immediate need to use, I worked on all the others I had posted at The Lessons of Phyz, my Teachers Pay Teachers store.

So here's what's available—an available in Google Docs format, most sold separately or in bundles (at an inadvisable discount).

The Mechanical Universe (All 52 episodes)

The Mechanical Universe High School Adaptations (All 28 Episodes)

Conceptual Physics Alive! with Paul Hewitt (All 34 episodes)

YouTube Physics (quite a variety of topics covered)

Physics Modules (Mechanics, Heat & Temperature, Waves & Light, E&M, and Modern)

Skepticism (we need this so much right now)

Breakthrough: The Ideas That Changed the World (All 6 episodes)

Cosmos: A Personal Voyage (Carl Sagan's 1980 series, all 13 episodes)

Cosmos: A Spacetime Odyssey (Neil deGrasse Tyson-hosted 2014 series, all 13 episodes)

One Strange Rock (Will Smith-hosts, great for NGSS "The Living World" biology, all 10 episodes)

Our Planet (Think Planet Earth, but with an edge, all 8 episodes)

How Earth Made Us / How the Earth Changed History (Excellent BBC series, all 5 episodes)

Earth Science (Mapping, Atmosphere, Water, Weather, Human Impact, Geology, Solar System, Galaxies)

Pandemic: How to Stop an Outbreak (2020 Netflix series, all 6 episodes)

Two dozen resources are free of charge. Bundles are often discounted so heavily that I get a warning from TPT that I've gone too far. If your school has licensed TPT School Access, then I suppose all the resources are free for you.

Not long into the pandemic, TPT created a method for converting PDFs into Google Docs. By the time it was available to sellers, I was already too deep into the pain-staking process of converting them myself by hand. Well, by computer, but you know what I mean. So I just plowed through into the summer until everything in my store was converted.

I hope you find something that can help you this year and beyond.

## Saturday, September 05, 2020

### Kinetic Karnival now on YouTube

Here's a post from 2009. Updated as I've added the videos to my YouTube channel. I downloaded them from Jearl Walker's MySpace page, where they were originally posted.

All six 30-minute episodes of Jearl Walker's classic television series, the Emmy-winning Kinetic Karnival, are available online at Walker's MySpace page. [Update: I can't access them on MySpace anymore, even in Chrome.] I recommend watching them before showing them in class, although I'm sure you'd do that anyway. There are a few brief moments that modern educators might find objectionable. Most of us find ways to work around such moments, but it's always best to be aware.

I developed video question sets for episodes 1, 2, 3, and 5. Students answer them while the video is in progress. They're up as PDFs in The Book of Phyz.

Here's a one-stop collection of Kinetic Karnival links for your convenience. If you like question sets matched to science videos, The Lessons of Phyz is the place for you.

1. Forces and Collisions [impact time and contact area]
In this episode, Jearl proves his virility and masculinity by chopping concrete bricks with his bare hands and volunteering as the meat for a “nail sandwich.”

Kinetic Karnival - Forces and Collisions - Question Set - Key

2. Rotation [circular motion and conservation of angular momentum]
I show this one in two distinct segments (one in my Physics 1 course, the other in AP Physics 2). The first third is devoted to circular motion. The second two-thirds is devoted to angular momentum. Do I dislike the blending of these distinct topics? Yes. Do I have the talent and ability to produce my own series? Not so much. In any case, this episode features Jearl in a swim suit!

Kinetic Karnival - Rotation
Video Question Set 1 (UCM)
Video Question Set 2 (Angular Momentum) - Key

3. Fluid Flow and Friction
In this episode, Jearl debunks the drain swirl myth from the bathtub, describes an early dating disaster, explains the tablecloth trick, and hangs a spoon from his nose.

4. Viscosity [non-newtonian fluids, quicksand, and corn starch]
Jearl enjoys tinkering with viscous and non-newtonian fluids. He gets stuck in quicksand and jumps feet-first into a pot of unflavored gravy.
Video [Sorry, I didn't grab it when I should have.]

5. The Leidenfrost Effect [heat transfer and phase change]
Arguably the best program of the series, though it does contain a "politically-incorrect/racially insensitive" moment. When Jearl complains about "the problem" with iron-cooked crepes, you might find the mute button on the remote control of your playback system. A few moments of mute will spare you an apologetic discussion afterward. Features the hand into molten lead, liquid nitrogen in the mouth, and firewalking.

6. The Science of Cooking
Jearl prepares a meal for a dinner date with a young lady. Along the way, he describes the physics and chemistry of a variety of dishes. And the date turns out as you might expect.
Video [Sorry, I didn't grab it when I should have.]

## Saturday, August 22, 2020

### Cosmos in the Classroom updated for Distance Learning

Carl Sagan's Cosmos: A Personal Voyage spoke to many of us of a certain age who were interested in science. I remember watching every episode of the series with my family as it aired on PBS in 1980.

That series remains relevant in science classrooms, today. I began showing it in my Physics course a few years ago. We watch one episode after each unit, and there is a set of questions for students to answer while each episode plays. Eventually, I posted those question sets to a Cosmos in the Classroom web page that I added to the phyz.org site.

In 2014, season 2 arrived. It was called Cosmos: A Spacetime Odyssey, and featured Neil deGrasse Tyson as host. I developed a question set for each episode and integrated that series into my Conceptual Physics and AP Physics 2 courses. (AP Physics 1 gets no Cosmos. Shoehorning Kirchhoff in with All Things Mechanics means we have no time for any enriching tangents.)

When I entered the strange, new (to me) world of Teachers Pay Teachers, my Cosmos question sets were early product offerings. Originally available only as a complete season bundle, I have since made individual episodes available while offering the complete set at a discount. The first episode is free.

I purchased both series on optical discs (DVD and BD) so that I could easily show episodes in class. In the era of streaming, both series have gone through various iterations of streaming/not streaming on various services. Presently, episodes of Sagan's 1980 series stream on YouTube and episodes of Tyson's 2014 series can be purchased on YouTube. It may stream on a pay service, too. I can't always keep up.

Showing these episodes during Distance Learning presents a new challenge. Any series that streams on YouTube is easy and can be assigned as an asynchronous activity. Non-streaming episodes can also be shown. But only over Zoom, during synchronous sessions.

But the question sets? In class, they'd be printed and given to students to write their answers on. Remember those days?

Soon after the pandemic shutdown and the imposition of crisis teaching, I slogged through the task of turning video question sets into Google Docs format, so I could assign student-editable copies to all my students in Google Classroom, and they could turn in their digital copies when they completed the assignment. The task of converting each and every question set was not at all enjoyable.

I've worked out (through trial and error) how best to show episodes to my classes over Zoom. But as my EL student population grew, the language-intensive nature of this exercise worried me more and more. Such is the challenge of language instruction in high school: we want it to be challenging, but we cannot leave our EL students behind.

To mitigate what could be an overwhelming language load, I sought out and linked transcripts to each episode of both series. It's an open question as to whether or not transcript support is enough. But I'm grateful that the transcripts are available.

The Cosmos in the Classroom page, newly updated with transcript links, Teachers Pay Teachers links, and video search links, can be found here:

I know that season 3, Cosmos: Possible Worlds, has been released. I hope to produce question sets for it someday. Perhaps a project for summer, 2021.

## Friday, August 14, 2020

### PASCO vs the Pandemic

I am sure everyone has a compelling narrative about how the COVID-19 pandemic upended their lives. This post is my story with an emphasis on how we responded at my company, PASCO scientific. One of our main responses was to create distance learning lab resources. They are described and linked to at the end of this post. Feel free to skip right to them.

At the end of February my wife and I found ourselves at the Kaanapali Beach Hotel in Maui. We have been going there annually for the last 6 years for what used to be my ski week break. We used to go every few years and take our daughter and son. After they were out of high school their schedules didn't permit it. I remember telling them about our plans to go to Maui when they were in college. They replied, "but we don't get that week off anymore". We said "we know" with big smiles on our faces. We had a great week for what would be our last trip for many months. On our last day we went to nearby historic Lahaina. We went on a whale watch trip and walked up and down Front street. We were joined by hundreds of cruise ship passengers who were shuttled into town on small boats. We learned a week later that the name of the ship was the Grand Princess and it had passengers and crew infected with COVID-19. This was the ship that was stranded in San Francisco Bay for weeks as they tried to decide what to do with them.

 Humpback whale spouts with the Grand Princess in the background

On our return we heard about the first known case of COVID-19 in the United States that was not due to travel. We were concerned because it was in nearby Sacramento. It also was troubling because the victim was not even given a test when they first went to the hospital with COVID-19 symptoms. Still, this was just one case so we felt safe about our plans to attend the Harry Potter and the Cursed Child play at the Curran theater in San Francisco. Our daughter is a big Harry Potter fan and this play was our birthday gift to her. We never considered not attending the play even after we learned that the cruise ship stranded in the Bay was the same one from Lahaina. We met our daughter, her boyfriend and two of her friends at the theater and had a great day. They were not concerned about COVID-19 but it did occupy a lot of our conversation. The coughing woman behind us caused some anxiety but no panic. The play is so long it is split into two parts with a long break in between. We had a nice dinner during the break at the San Francisco landmark, John's Grill. Little did we know that this would be our last large public gathering for many months.

 One last large public gathering before the lock down, March 8 2020

We remained away from the PASCO office for a lot longer than the original 4/10 specified in the Placer County shelter in place order. We were instructed not to work but were paid our full salary until March 28. After that we could use paid time off or file for unemployment. I did the latter and found the online system worked pretty well. I never thought I would file for unemployment but since I had paid my taxes all those years, I went ahead and did it. My wife and I were thankful every day that we had recently moved from the Bay Area to a house on a lake near Auburn, California. The lake is like having a 240 acre back yard. I did a lot while in lock down, some of it even useful. Among my pandemic projects were a set of labs and videos experimenting with a chain on a pulley and a chain hitting the ground. I later used this work to create a talk for the virtual AAPT summer meeting.

 The view from our deck as mist rises from Lake of the Pines at sunrise

We remained in lock down until 5/4. At that point my group and a few other key personnel were allowed back into the office. I felt safe since there were few people there and we were spaced very far apart. We were scheduled to work a 4-day 32-hour week so no more unemployment. I was able to work at home but when you develop physics curriculum you need a lot of stuff and I missed my stuff! Over the next couple of weeks more people started coming in to the office with everyone back by 5/18. We also went back to a 40 hour week. Everyone wears a mask when away from their cubicle and meetings are on Zoom. Some employees are starting to work part-time at home to reduce the density at the office too. I still feel safe there.

I had a lot of things to work on but one was a collection of labs for two new products, the Physics Starter Lab Station and the Physics Extension Lab Station. These are bundled wireless sensors that come with a lab booklet, 10 labs for each station. There are chemistry lab stations , biology lab stations, elementary lab stations, middle school lab stations, and agricultural science lab stations too but I am going to focus on physics. We also committed to make a video for each of the labs in the Physics Starter Lab Station. This was an opportunity to make more distance learning labs. Originally we had wanted to make some for first semester topics but the lock down prevented that. Over the last couple of months I finished creating the labs and we made videos and posted data files for the labs listed below:

Position, Distance, and Displacement

Newton's Second Law

Designing and Testing Crash Cushions

Impulse and Change in Velocity

We plan to make more of these but they are on hold because of our new project called PASCO Academy. It was inspired by the popularity of the distance learning videos but motivated by the need to create something that will bring in revenue. Schools, teachers, and home schoolers that subscribe to PASCO Academy will get access to 15 weeks of a lab video program, access to our online textbooks, and unlimited license to SPARKvue software. The lab program will consist of a teacher preparation video, a lab overview and data collection video for students, and a follow up analysis and discussion video for students. The labs will all come from the Essential Physics or Essential Chemistry online textbooks that are targeted at a regular to honors level class. My colleague JJ Plank and I are in charge of the physics PASCO Academy. If you found the distance learning video labs useful I suggest you check it out.

## Monday, August 10, 2020

### Remote Learning Best Practices (Sort of)

I've been teaching high school physics for 22+ years, and for 18 of those years I've also been a professor at a nearby community college, where I teach every summer. Most of my colleagues think that I need to have my head examined for voluntarily teaching in the summertime, but - what can I say? - I'm hooked on this teaching gig.

This past summer I had the opportunity to teach a completely online class for my college, and it was a great experience! I’ll admit that at first I was concerned about delving into this brave, new world of remote teaching, but now that I’ve gone through an entire course, start-to-finish, I wanted to share with you my thoughts and advice for how to teach a class remotely in terms of what I have found to be best practices. Of course, not all of this advice will apply equally for all situations or classes, and I encourage you to experiment with what works best for you and your students.

1. Synchronous vs. Asynchronous Instruction: having done asynchronous teaching last spring for my high school and synchronous teaching for my college this summer, I think it is far better to do live, synchronous teaching. It provides a regular structure for the students, and many are reassured to have regular "face-to-face” contact with their teacher. However, I plan to structure my classes with a strong asynchronous component as well – in the form of required, regular discussion board posts to keep students engaged and accountable even when they aren’t “in class”.

2. Student Interaction During Live Class: if you are doing a class live, then something that worked out very well for me was for students to disable their video and audio. The reason for this is two-fold: 1) It lessens the bandwidth that you need to use (which decreases lagging and/or dropped sessions), and 2) it lessens distraction on the students’ part since they have to watch you. In terms of having students interact live, the way that worked best for me is to have them post questions and answers in the online chat; of course, you have to keep an eye on that chat window while you’re doing a lecture, so you have to be on your game!

3. Make Use of Breakout Rooms: the breakout room feature is very helpful; whether it was having my class do group discussion, in-class problem solving, or remote lab work, I found that providing time for students to work directly with each other was critical to both their learning and positive social interaction. I recommend having some kind of breakout room session at least once per week, but make sure you “run laps” and drop in to keep those kiddos on task!

4. Record Your Live Class: for every live lecture/class I did at the college this summer, I recorded the sessions and uploaded the videos daily so that students who wished to go back through the lesson could do so. This is also very useful for students who, for whatever reason, were absent from class.

5. Outfit Your Teaching Space: make sure that you have your own teaching space or “classroom” at home, if you’re teaching remotely. This will help provide you with a degree of familiarity and comfort, and if you are comfortable it will help set your students more at ease.

6. Use Tech to Your Advantage: as a follow up to #5, if you are doing live teaching, there are a *lot* of options – you can use your computer’s webcam and set up a white board to lecture at; you can use a digital writing pad (I personally use a Gaomon, cost \$70 on Amazon) in conjunction with the Paint program on your computer (Paint is easier to use and more versatile than the digital whiteboard on Zoom or Google Meet, in my view); you can also get a document camera to write on paper directly for display; on that last note, doc cams are rather expensive and can be quite finicky, but here’s a cheap teacher hack that I’ve used in a pinch J

Make your smartphone a webcam - https://www.howtogeek.com/669589/how-to-use-your-iphone-as-a-webcam

7. Regular Assessments: again, in order to provide structure and a degree of accountability for students, I recommend that you work regular assessments into your remote teaching. For example, something I did at both my high school last spring and the college this summer is require students to do a weekly quiz over that week’s material. Working properly with your institution's online CMS, you can set up such assessments to be timed (and adjusted accordingly for students with extended time) and draw questions from a question bank so that no two students’ quizzes look exactly the same, etc. There are lots of options, and if you play around with it you’ll find something that works for you.

8. Take Brief Breaks: my college class over the summer was 3-hours every morning, Monday through Thursday, and that is a *lot* of screen time! Both teachers and students this fall semester will be experiencing a lot of screen time as well, so try to work in regular, short (roughly 5-10 minute) breaks during any live classes to give your eyes a rest, go to the restroom, etc.

9. Check Email Regularly: some students won’t feel comfortable engaging you in class, so make sure to check your email a few times per day to see if they’ve sent you private questions. I’ve found that many students are quite appreciative of that “personal” touch.

10. Embrace the Insanity & Ask for Help: honestly, these past months I’ve felt more like a first-year teacher than any other time since I actually was a first-year teacher back in 1998! While it has been quite a challenge, I’ve taken the view that this situation is an opportunity to adjust and hone my skills as a teacher, and that positive outlook has definitely helped me during the rough patches. Also, DO NOT HESITATE to ask your colleagues for assistance when you need it. Due to the wonders of modern technology (such as this blog), we are not separate from each other, so maintain your connections with your colleagues and lift each other up. In short, we can view this challenge in the following manner…

Those are my thoughts and advice, such as they are; if you have any questions, feel free to reach out. Semper Gumby! J

Cheers – Matt Lowry

## Saturday, August 08, 2020

### Phone app Phyphox looks promising

Like many, I've been trying to get a handle on potential distance learning tools over Summer Nocation. It seems there is a vast library of resources and web tools for instruction in general and physics instruction.

I use PhET already. I'm working with my district to gain access to Pivot Interactives. My district's LMS is Google Classroom, while our SIS is Q (Aequitas).

I have never used Flipgrid, Padlet (or Wakelet), EdPuzzle, Quizizz, Socrative, Screencastify or Screencast-o-matic, Loom, Zoom, Peardeck, Jamboard, Desmos, Edulastic, Flippity, or any other must-have tool that is explained in a video that features a noodling xylophone over a strummed ukulele while a narrator announces, "This ... is <ProductName>. The tool that lets you <do the thing you didn't even know was critical to your instruction program, but is—especially now in distance learning>". If a personal favorite of yours is in that list, you may be tempted to cast me as a luddite.

There is no shortage of webinars of experts who have been using these tools for years, where importance of Bitmoji is made unambiguous, as is the value of carefully curating of your virtual Zoom background.

At the virtual AAPT Summer Meeting 2020, the phone app, Phyphox, caught my eye (thanks to Susan Johnston's presentation). Like Google's Science Journal app, it leverages a phone's many sensors.

In addition to the activities available from Phyphox, Lawrence Livermore National Laboratory has prepared a series of physics distance learning lessons. I already had the app on my phone, but I was compelled to open it and play around on my own.

As with so many things in the realm of Distance Learning, there is a question as to whether it's appropriate to assume our students have access to a smartphone.

I'm not going to be able to construct a new and better version of the curriculum I've been honing for over 30 years in the snap of a finger. Or at all. If things work out, we'll be back to face-to-face instruction by ... 2022 is my prognostication. Maybe even Fall, 2021. For now, we're going to do our best with the situation we're in.

## Sunday, July 26, 2020

### Getting up to speed on airborne virus transmission

It's natural for us to harbor pride in our former students as they accomplish feats in the world. Of late, Dr. Linsey Marr, professor of environmental engineering at Virginia Tech has been filling my mainstream and social media feeds. Her insights into aerosol virus transmission are sought out by agencies and reporters. She's even smarter now than she was when she burned through my AP Physics B course once upon a time. So I'm beaming already.

When I tuned into this recorded webinar, I went from beaming too bursting. Because now she's the teacher and is doing a great job if it. In reality, she's been an excellent teacher for many years, but I've never managed to sit in on one of her classes.

In any case, it seems we all need to have a fundamental understanding of airborne virus transmission as we contemplate returning to classroom amid the pandemic. As always, knowledge is power. This is knowledge I had never hoped to be conversant in. But here we are.

This is not a brief lesson, but it is worth your time if you're a classroom teacher in the era of COVID-19.

SARS CoV 2 in Indoor Air: Principles and Scenarios

## Tuesday, July 21, 2020

### Virtual Lab Reports

As we all embark on an uncertain journey of virtual learning, many science teachers are wondering what labs may look like in this virtual space. Most of us are familiar with PhET simulations and other resources to do a virtual lab, but how do students communicate their thinking? I was inspired by Lyndsay Schobel's tweet to write up a few quick thoughts. I'm no expert, but I thought I'd share things that I've tried.

## Some Digital Lab Report Templates

In the past, I've used the template linked above with varying levels of success. I like that it prompts students what to do and gives examples of what is expected. This template is for a model development lab, where students are developing the mathematical model of a physical situation. This template is easily adapted to most model development labs, and it's easy to explicitly prompt linearization when that scaffold is needed.

By the way, the particular lab that is presented in that template is one designed by Marta Stoeckel. She wrote about it in her The Physics Teacher article Defining Electric Potential Difference by Moving a Multimeter’s Ground Probe. Which leads me to my next point.

Marta's lab template is better, and you can find it at the link below.

It is designed for in-person instruction, but I think that it could be adapted pretty easily to virtual learning. It is more involved, but it also provides more scaffolding. I'll probably look at adapting it for my own curriculum this year.

## Digital Graphs Tools

I have two tools I recommend: Desmos and Vernier's Graphical Analysis, and both are free! Tutorials on how to use them for graphing can be found here for Desmos and here for Graphical Analysis. A review of each follows.

Desmos wins as the the most intuitive math software that's ever been made. It also has the benefit of being a more universal tool, and your students will likely be familiar with it from math class. That sort of cross-curricular software support is great. It also runs in-browser, so you don't need to download anything. It's biggest drawback is that it is a math software first and a data analysis software second. As a result, sometimes data analysis things can slip through the cracks (like remembering to label your axes).

Graphical Analysis is made with graphing data in mind, which is its biggest benefit. It explicitly prompts students for axis labels and units. It also has linearization tools (tutorial here) built in as a feature. If your school has Vernier Equipment like ours does, you are also getting the students familiar with software with which their equipment can interface. The drawbacks are that Graphical Analysis requires a download (sometimes a pain for Chromebooks) and that it isn't a more widely used tool like Desmos.

Since Graphical Analysis is software and not a cloud-based solution, students also need to save their work as they are working. I've found that this is not common practice among many of my students who have grown up in the Google Suite age, so they need to be reminded of that.

If your students have access to a Windows or Mac computer and you want them to consider uncertainty, Kelly O'Shea has recommended LinReg in the past.

## Where students need direct instruction

The biggest place students need direct instruction is in turning their graph into a readable image. Both Desmos and Graphical Analysis have options to export graphs as image files, but many students do not choose this option. Instead, they'll take screenshots of their work and then upload the screenshot. This often leads to a graph image with illegible axes.

Students also create graphs with a lot of white space instead of making their data fit the graph window. Again, this is not hard to fix, but you need to provide students with instruction on how to fix it.

I'd recommend just having students resubmit graphs without penalty until they get it right. If you're annoying enough, they'll only make the mistake once. This is one of the benefits of Google Doc based lab reports--they can always be updated!

## Thursday, July 09, 2020

### My Flexible Hybrid Learning Plan

Welcome to my debut Blog of Phyz post! I was encouraged by Dean Baird to write a bit about my current flexible hybrid learning plan for the 2020-2021 school year that I posted on Twitter. Great idea! I hope that it can be helpful to others as they try to plan in the face of uncertainty.

## The Plan

Let's cut to the chase. Here is the outline for my plan. The rationale follows.

It is currently based on my typical pre-COVID schedule, where I teach a class two 105 minute blocks and one 50 minute class per week. It's likely that I will have to change the times, but I think the philosophy behind it is solid and adaptable.

## Guiding Principles

There were three guiding principles in making this schedule: simplicity, consistency, and flexibility.

Simplicity. This structure allows me to make good use of many of the high-quality resources that already exist, such as TIPERS, Ranking Tasks, Flipping Physics videos, Interactive Lecture Demonstrations, and so on.

Consistency. The students will see the same general structure each week, and they will know what to expect if they have to miss class. There should never be any surprises. Hopefully this reduces the "Hey, Mr. Milliano! Did I miss anything? What did I miss?" type questions. They'll know to check the recorded videos and their independent module for the week.

Flexibility. Much of this plan is structured around helping students to self-study and manage their own time. Even if we start the school year in-person, I have a suspicion that we will be online at some point. Students will need to know how to self-study, so we should explicitly prepare them for that while we're together. The teacher-led parts of the plan are things that I'd likely be able to do over video or Zoom, allowing them to work for in-person or online classes.

## Independent Modules

Each module would be one week long, starting on Wednesday and ending the following Tuesday.

A module would consist of seven 30-minute tasks, three to be completed in class and four to be completed at home. This could be adjusted to five 30-minute tasks and one 60-minute task, or so on.

These modules would each include at least one of each of the following.
• An information transfer task. This will often be a student-choice between reading the textbook or watching Flipping Physics videos. For accountability, I will likely have students post pictures of their notes and respond to discussion board prompts in our LMS.
• A virtual lab or activity. These will come from the usual suspects: PhET, The Physics Classroom, Pivot Interactives, etc.
• Sense-making tasks. These will include traditional problems, non-traditional problems, making Flipgrid videos explaining a simulation, Google Meets with classmates to collaborate and discuss ideas, posting on discussion boards, writing activities, and more.
Students will be asked to plan their own schedule, with guidance from me and the help of a graphic organizer that I'll make. As an incentive to stick to the plan and as an accountability measure, I'll check in with each student during their independent work time and see if they've stuck to their plan. If so, I'll give them a stamp or a sticker. (I'll never cease to be amazed at how motivating stamps and stickers are to 15-18 year-old students.)

## Assessment

The grade will be almost entirely based on weekly quizzes, except for the occasional lab report. This means no long unit tests (to take or to grade)! I will use a version of the 10-8-6-5 flavor of Standards-Based Grading described by Kelly O'Shea on her blog.

The weekly quiz can assess any standard from throughout the whole year, and most standards will be assessed multiple times in class. The most recent standard grade will always replace an older one. Yes, even if it's worse. (Although that rarely happens.)

## Student-initiated individual reassessment

Students will have the option to reassess any standard they want throughout the whole year, assuming they have put in the work to understand it better than they did previously. I will have several policies in place to make sure that these reassessments are (a) genuinely reflective for the student and (b) not an administrative nightmare for me.
• Reassessments will be taken on Fridays in class during the typical self-study time. This gives me a specific time to focus on this reassessments, rather than try to do them in random spurts throughout the week.
• The student must sign up to take a reassessment by the Tuesday of the week they want to reassess. This tells me that the student has put thought into what they want to reassess.
• When signing up, the student must provide concrete evidence that they have done extra practice on that standard. This tells me that they have learned from their past mistakes and have put in the work to refine their thinking.
• The student can only reassess two standards per week, and they must be from the same unit. This helps me write new assessments or find questions quickly and easily.
• I will only write reassessments for two units and four standards per week. This means I'm not trying to write too many new assessments per week.
• Only x number of students per class can reassess in a given week. I don't know what the optimal number for x is, but I know there needs to be a limit.
• There is a definite final date to reassess. For me, that's Friday, December 4, 2020 for the first semester.

## Why I like this plan

This plan provides flexibility. There is so much uncertainty surrounding school plans for next fall, and we all know anything could change at the drop of a hat. I believe that this structure could provide the flexibility needed to work fully in-person, fully online, or in a hybrid model. It also allows me to do both online and face-to-face with roughly the same lesson plan.

This plan is not complete. I teach in a St. Louis county school, and all county districts have agreed to release their plans together on July 20. So I don't really know what my schedule will look like yet. With this structure, though, I am confident that I can start working on building some independent study modules.

## Some acknowledgements

This plan has been heavily influenced by several conversations that I've had recently with physics teachers on Twitter. I'd like to thank Wesley Morgan for encouraging me to keep things simple this year, Frank Noschese for talking about his plan to make one plan that works in any scenario, and Phillip Easton for sharing how his class has been structured in a similar way in the past.