Category: Activities

ABCs of How We Learn: F is for Feedback
Activities · Science of Learning

ABCs of How We Learn: F is for Feedback

Marianna Ruggerio3 Comments

“Ever tried. Ever failed. No matter. Try again. Fail again. Fail better”

I’ve seen these words by Samuel Beckett on posters and in classrooms. The intention is to support the idea of the classroom as a safe space to try and fail. But failure without actional feedback is just failure. The classroom environment that has high expectations and high support is also an environment with ample opportunities for feedback.

Feedback can come in a lot of degrees, from a minimal “correct/incorrect” to highly detailed narrative regarding the student choices. For most of our students, the feedback they require should fall somewhere between specific discrepancy and elaborative.

Unfortunately many students are used to only getting feedback after a summative assessment, and without retakes any feedback is usually worthless. (Consider the student who crumples the test and throws it away immediately).

In order for feedback to be effective, it needs to be specific, timely, understandable, nonthreatening and revisable. (For the Hattie/Visible Learning enthusiasts, the weighted mean effect size is 0.92)

Teacher Led Peer Evaluations

A few years ago I started requiring homework submissions as scans to google classroom by the start of the school day. This allows me to do a quick skim through student work and make decisions for class prior to seeing students. Below is a sequence of student work I wanted to review and discuss with students.

Responses are left anonymous, but I use them as a way to provide feedback via whole group discussion. In this sequence you can see the work going from pretty disorganized to much more logical and detailed. I can lead this discussion, or I can ask for student observations about the work.

Student Self-Evaluations

I’ve written before about using self-evaluations for student problem solving process. I haven’t crafted these rubrics for every unit, but I’ve found that for some students this helps them focus on the problem solving routine, rather than just the answer.

Google Form Check Ups

The check up is a follow up I use when students are engaging in practice that is not scored, checked or graded by me the teacher. You can see the full blog post on this process here. During the last 10-15 minutes of class I have students engage in several activities in the google form. The first is a self-evaluation of the learning objectives. Sometimes I will ask them to rate their work from the problem set using a rubric I provide. Last, I will put 1-2 items from the day’s practice and ask students to explain the answer. An example from this past week is below:

After students submit their answer and click next, the following pops up. It provides them with the answer and an explanation behind it.

For what it’s worth, I was VERY impressed by the number of students who got a similar problem to this one correct on their exams this past week! Students are reporting that circuits has been the easiest unit yet, but the reality is that there is a great deal of conceptual heavy lifting!

One of the most important features of all of these feedback forms is that they are happening during the learning process. This means that students can very quickly adjust their course of action in order to move towards the desired results.

Activities · Science of Learning

ABCs of How We Learn: D is for Deliberate Practice

Marianna Ruggerio2 Comments

Deliberate practice is what kicked off this whole series. I did a deliberate practice exercise last Friday as part of my AP Review in which we focused on graph linearization on the AP FRQs. I was so excited about it I decided to write about it.

This isn’t the first time I’ve intentionally paired an activity in my classroom with deliberate practice. I’ve also paired it with the Building Thinking Classrooms strategy using Mild, Medium and Spicy problems.

Deliberate practice is defined as applying focused and effortful practice to develop specific skills and concepts beyond one’s current ability.

The analogies to interests and hobbies abound. Running drills in sports to get body mechanics just right, Hanon finger exercises to help with piano dexterity, or point coordination exercises to improve hand-eye coordination and drawing with your shoulder.

These drills are rarely exciting, often frustrating but so necessary to move to the next level. In other words, they are focused and effortful!

The challenge with students (or anyone really) is that students tend to practice the things they are already good at. The challenge for teachers is that if we want students to engage in deliberate practice to improve their skills, we have to get them focused in on what they are really struggling with, and we know that’s not going to feel great.

AP classroom has recently made deliberate practice really east for educators. You can log into your AP classroom, go to Reports, then Content & Skills Performance. Then you can “generate practice quiz” in which you can make selections for content and/or skill based on the student level of performance. I’ve found this to be a really valuable tool this year to help my students focus in on that deliberate practice.

Another great example of a resource for deliberate practice are the Physics Classroom concept checkers. I’ve shared some of my written companions for these assignments which provide students some of the scaffolding they need to build that particular skill set.

I recently heard an eduinfluencer make the claim that teachers can only name and describe 3 evidence based strategies they use in their classroom. Challenge accepted. Each day I’m working through the book The ABCs of How We Learn and pairing a strategy with physics content/activities in my classroom.

ABCs of How We Learn in Physics: Analogy
Activities · Science of Learning

ABCs of How We Learn in Physics: Analogy

Marianna Ruggerio2 Comments

Shortly after completing my MEd I was asked to teach the intro to educational psychology course at Rockford University. The course had recently been redesigned to focus on cognitive psychology and the science of learning. Eager, I looked around for other models at various institutions and reached out to a few collegues. One of whom referred me to the book “The ABCs of How We Learn.” It’s a wonderful and digestable text that goes into the research, provides some examples and good/bad uses of each strategy.

At a recent institute day the keynote speaker shared that in his personal research he found that, on average, teachers could only name and accurately describe three strategies they use in the classroom. So, here’s my challenge to myself: 26 strategies and 26 direct applications to the physics classroom.

A is for Analogy

What makes an analogy? Can you name one in physics? God please not the water pump as a circuit example. An analogy is where two examples have the same deep structure. Analogy then becomes a valuable tool for helping novices begin to pay attention to deep vs surface structures.

There are two ways in which we use analogies. The first is the one you are probably thinking of when you consider analogy… the water pump for a circuit, or lanes of traffic to explain what happens to current in series vs. parallel. As teachers I think we use these examples readily in the classroom as we make abstract ideas more concrete.

There is, however, an additional way to use analogy and that is by taking two or more examples and asking students to identify what about those examples is similar. I noticed that my students this year were having a more difficult time that my previous students making this leap. Have your students ever said to you “but you never taught us this problem!” or “you need to show us more problems!”. It’s not really the number of problems, it’s really a transferrence and deep structure problem. Students are not recognizing that the problem at hand is, indeed, the same problem.

To address this I decided to set up a two-for-one cognitive strategy task (document here). First, I asked students to retrieve the worked example from the previous day. In the first instance of this task I asked them to retrieve the derivation for the moment of inerta of a rod about its end. Next, I provided students with a similar, but different problem.

For this first task I felt the problem was almost too similar, but their hesitation proved otherwise. The task was to derive the moment of inertia for a triangular rod about its end where the linear mass density was provided as a function of position. (see below)

However, what I asked students to do first was to identify what about this problem was similar and different to the previous problem. After they took a stab at this we regrouped so we could discuss what I was looking for. It is similar in that it’s the rotational inertia of a rod-like object about its end. It’s different in that the linear mass density is non-uniform and is a function. Then students executed the task. As we moved through the rest of the rotation unit (where analogies abound!) this became my go-to phrase! “Before you begin, what is similar and different to what you’ve seen before?”

Paper Companion Activities for Pivot Interactives
Activities · Teaching Methods

Paper Companion Activities for Pivot Interactives

Marianna Ruggerio2 Comments

You know how I feel about online work! (Looking for Physics Classroom Companion Worksheets? Find them Here!)

When I took high school physics almost everything was online. From physics classroom assignments, to the dreaded WebAssign, it was online. And because it was online, I like others, gamed the system (pre chat GPT). You know a certain number is going to show up somewhere in the answers? Enter it in all the blanks for the first submission so you can focus on the actual calculations. On the flip side was the part where you tried the problem so many times by the time you got it right you had no idea what actually worked. For the better part of my career I’ve been vehemently against all forms of online homework. There’s something about that screen that just puts a stop to the idea of using scratch paper for novice learners and we can’t have that!

(For what it’s worth, when AP went all digital I did NOT feel the urge to go digital in my classroom. I continued to do everything on paper. When APs came around I found my goal was acheived: I proctored the macro exam and did a count. 80% of physics students were using their scratch paper during the exam, while only 30% of non-physics students used their paper.)

The first exception I made to online learning was Pivot Interactives. I was using Peter’s work back when they were “Direct Measurement Videos” which meant I had paper copies originally, anyway. As Pivot upped their game (including deep randomization and autograding) I started using some of these assignments since it sure made my life easier!

However, what I’m finding with my students this year is that like my Webassign days, students are doing the minimum to get all the green checks. This looks like not reading the prompts that explain what they’re about to do next and why, not actually collecting the data for the graph and totally missing the connections between the sample measurements and the data collection.

So, I’ve started to reimplement some paper versions.

The Activities: A Journey of Trial and Error

Earlier this year I assigned the helmet collisions activity. I added a prompt at the end that requested students to do the following:

  • What was the purpose of the activity?
  • Describe the procedure for conducting the investigation
  • Describe the calculations you made and why we made each calculation. You should include details regarding your values!
  • Describe what we learned from this activity about helmets as it relates to the impulse-change in momentum relationship.

This was ok, but I, arguably did this a bit hastily. I realized I wanted these documents handwritten and maybe a bit more depth/scaffholding.

A few weeks later I assigned the Explosions (Not Really) activity.

I knew that students would totally ditch all of the methods we had been using, so I decided to give them a paper to complete before the activity that related to the activity. This required them to complete the calculations with similar, but easy numbers and then have me check their work prior to the activity. This got a good chunk of kids on board, but some still struggled with the transference.

Still not completely satisfied, this past week I assigned the “Intro to Transverse Waves” activity. In this activity students are going to linearize a graph. This is a skill we don’t really cover in my regular level physics, but I like doing it at this point in the year because it’s such a powerful tool. As I anticipated, many students were ignoring the text about linearization completely. I chose a different approach to the paper copy.

I gave students this document which contains the following prompts:

First, I asked them to describe to me some of the new vocab as well as how we obtained our measurements

Next, I use a modified template from the Patterns Curriculum when students write conclusions in labs where we have graphs. It looks like this:

After investigating the behavior _______________, I conclude that there is a ______________________relationship between the [independent variable name]  and the [dependent variable name] As the [independent variable] kept increasing, the [dependent variable]_____________________________. This system of a ___________________ can be mathematically modeled as:

[write the final equation]

where the constant  [slope value]  is the [description of slope for this experiment] . 

I require students to write the ENTIRE paragraph from start to finish. This is not a fill in the blank activity.

This is currently my favorite interaction of the paper follow up and I’ll probably build more of these moving forward. I’m really in love with the patterns physics conclusions because it really requires students to put everything together.

Grading

I’ve noticed there’s a VERY strong correlation on these summaries between students who took the activity seriously and learned from it, vs students who did not. Because of this, the only thing I really need to grade with care is the conclusion paragraph itself. If students did the lab correctly, this paragraph looks great. If not, they usually don’t do well on this.

Do you do anything like this? What does it look like? How do you support genuine learning using online platforms?

Teaching Students How to Score Better
Activities · Classroom Issues · In My Class Today

Teaching Students How to Score Better

Marianna Ruggerio2 Comments

At the American Association of Physics Teachers Winter Meeting I had the privilege of presenting in literally the best session of the entire conference (no bias here at all). Magically, all four of our presentations beautifully complimented one another and related deeply to engaging students in metacognitive skills.

I transitioned districts this year. In my previous district I worked with a lot of students in the gifted program, a lot of students in the creative and performing arts program (who are basically also gifted) and within this culture and climate, all kids benefitted, even the ones who were not in a special program. For years I was able to get students on board with the Expert Game, and the Science of Learning Physics some trust in the process, and good relationships. This year, that hasn’t quite cut it. I’d been thinking about a way to somehow “teach” students in a way that feel like “teaching” to them about how to learn, study and grow so they might buy into the idea (which is really nothing new).

I had been digging back into Powerful Teaching and some kind of workshop was begining to materialize, albeit very, very fuzzy. And then, at Winter Meeting, Aaron Titus gets up and shares that he offers a “How to Do Better on the Test” workshop which turns out to be “How to Learn”

The workshop is grounded in the work of Dr. Saundra McGuire. There are a lot of resources of hers around the web, like this lecture here on metacognition, but primarily she has a sweet little book called Teach Yourself How to Learn. It’s short, sweet, to the point and a lot of fun to read. Dr. McGuire is a retired chemistry professor and Director Emerita of the Center for Academic Success. She is also an awardee of the Presidential Award for Excellence in Math and Science Mentorship.

Immediately in chapter one she discusses one of the aspects about college that is hardest for students: getting As and Bs in high school often comes down to memorization and regurgitation. Now, before you come with fire I know that many of us (especially if we teach AP, and definitely if you enjoy my blog) are making students do incredible things. But I also know that you can probably name more than a handful of colleagues who don’t push their students beyond memorization. Teachers who produce study guides that are basically a carbon copy of the exam. Exams that are almost all multiple choice and the math is strictly plug and chug. The dreaded triangle to “support” students doing equations like F=ma. And if not the teachers themselves, some really great high school students simply don’t get pushed beyond needing to simply show up to class to learn the information. They can get away with minimal to no homework and no studying and still do okay in the class because we see them every single day and they work hard in our rooms.

So the workshop starts by introducing students to Bloom’s Taxonomy and we have a conversation about what level they are operating at most of the time, compared to what level they need to operate at for AP Physics. What level do they think they need to operate at in college?

And sure enough, if you pull up the science practices and skills for AP the word “create” is literally all over the place. The top of the pyramid.

From here we took a look at a recent exam question. First I asked them a simple question:

Which of the following is true about work?

  1. Work is effort
  2. Work is a change in energy
  3. Work is a force

They all know the answer. And this is a recall answer.

Then I showed them the exam question (they did really poorly on). While the question fundamentally was about the fact that work is a change in energy, what they were asked to do was apply the concept of taking an integral to calculate work and then create a graphical representation.

From here we discussed the differences between studying and learning and posed the question, “which would you work harder for? To study to get an A on a test, or prepare to teach the material to the class?”

The latter half of the workshop is about sharing strategies for doing homework, reading the text, and using practice exams. (You can find all of these in Dr. McGuire’s work and resources!)

I summarized some of these along with my personal favorites into the following list:

  • When you get home from school, write down everything you can remember from class that day, then compare with your class notes to identify/fill the gaps
  • Did you solve some problems? Grab a clean sheet of paper and solve the problem again. Compare to the example and make notes regarding your forgetting/gaps
  • Create a concept map to tie together big ideas and conceptual details
  • Make “teacher notes” as if you were preparing to teach the material
  • Aim for 100% mastery when you sit to study, not 85-90

As we wrapped up, the most important part of this workshop was asking students to make a commitment to do something different in the next 24 hours. I had students submit these along with some additional reflections. There were two that stood out to me today. One student reflected, “The reason this class is so challenging for me is because I haven’t had a class besides maybe Calc that required me to be at that creating level.”

A second student made an observation that knocked me over in joy:

“Physics is more than just who is smarter and has the ability to think at a higher level.”

And with that, I’m signing off. I’m going to attach my version of the slides, but everything is very much thanks to the work of Aaron Titus and Saundra McGuire.

Waves Intro Activity with Virtual Ripple Tank
Activities · In My Class Today

Waves Intro Activity with Virtual Ripple Tank

Marianna RuggerioLeave a comment

When I was in college my E&M professor introduced me to the falstad apps. It was literally this guy who created a bunch of different JAVA sims. E&M is notoriously challenging due to needing to think and reason in three-dimensional space, so we were encouraged to use the apps to help us visualize static fields.

When I started teaching I decided to poke around and see what else Falstad had created. One of his simulations I use year over year is his ripple tank. It’s incredibly powerful and way less cumbersome than setting up the actual water tables (which was just unfeasible being the only physics teacher with 3 preps)

I just finished my intro activity today so I figured I might as well share. You can find the simulations here.

When the app opens it’s pretty simple. A “faucet” wave like the one in the Phet sim is present. You can see the sliders to adjust for damping and frequency. You can move the source where ever you like and can even toggle into 3D view

What’s pretty awesome is the list of “examples” you can select from the drop down menu.

Single slit, double slit, two-sources, refraction, total internal reflection and a whole slew of topics. You also have complete freedom to add to the simulation using the “add” menu bar at the top.

For my students, we start our waves unit in the following way.

First, we watch the slo mo guys film this ginormous 90 foot wave... with ducks…. which is awesome.

There’s a lot of really great phenomena here. From constructive interference, to refraction and lenses (pay attention to the grid image in the column) to the idea that waves transport energy, not matter.

Next, students head to the sim. I provide them directions on this document and the record their observations on this one.

This activity typically takes a class period and a half. For my advanced students they can usually finish in a class period or I can assign the rest for homework.

When students return the following day, I put this graphic organizer up and prompt them to write their own definition of the behavior based on their observations and a diagram to go with it

During the unit I come back to this app quite often.

We discuss how the design of an auditorium is based on nodal lines

I can drag the single source around to demonstrate doppler effect and sonic booms

If there’s a phenomena I want students to be able to observe, pause and manipulate… there’s usually a way to do it.

Written Companions for Physics Classroom Practice
Activities

Written Companions for Physics Classroom Practice

Marianna Ruggerio4 Comments

The Physics Classroom holds a place near and dear to my heart.

For years I thought it was my special secret. Long, long ago the url was something like physicsclassroom.glenbrook225.k12.il.us because it was a site hosted on my High School’s sever. The main author was Tom Henderson, one of the best educators at GBS. Tom taught the most advanced freshman in chem-phys, as well as the conceptual physics course. He had a great handle on meeting kids where they were at and explaining physics in a way that made sense as a student.

It wasn’t until much later I realzied that physics classroom was a well known resource for physics teachers across the nation.

As a student, something I realized was that what I found fun, challenging and helpful to my learning in physics was often a barrier and frustration to my classmates. Getting an “O Drats” without a way or opportunity to reflect or see where an error was made became maddening and frustrating. At the same time the essence of drilling a tiny skill is so valuable for long term learning.

I steered clear of most online homeworks for a long, long time (webassign also traumatized me). I knew that too often the real work that needed to happen to actually learn was skipped by most students in search of elusive green checks. By the time you got the checks, you had no memory of what actually worked.

Over the last few years I’ve started developing handouts to go along with some of the physics classroom activity sets. I only have a few, but enough that I feel like they are worth sharing publicly at this point. The goal is to get students thinking, writing and documenting as they work through the physics classrom activities. It also provides me with documentation. I will admit, another motivation for this was the fact that I did not have a paid subscription to task tracker. Now that I do, I’m developing more of these and will continue to share and post them here as I develop them.

What I’ve found is that more students are able to move through more problems with more success and confidence. Definitely a win! They hate me for slowing them down with the paper documentation, but I see it as a win.

Without further ado, here is the list:

Kinematics

Match That Graph Interactive

In the paper document (preview below) I ask students to first describe the motion in words. This way, when they watch the little car drive across the screen and make the dot diagram, they know what they are looking for

Kinematics Calculator Pad Sets

In the paper document, students are prompted to make their picture, their chart of variables and solve the problem by selecting an equation then substituting values as needed. This is a second version (sample below) that is specific to set 12, and provides more room for student work.

Momentum

Concept Checker: Case Studies Impulse and Force

The first few pages of this document are notes in which we construct the momentum bar charts for different situations and identify what is the same and different. Then students go to the concept checker and I ask them to create the bar charts and document the similarities/differences prior to making their selections. A preview is below and here is the handout

Work and Energy

This document can be used for the calcpad sets. I ask students to draw a picture, construct a bar chart, and solve the problem starting with conservation of energy. Preview below

Waves

Open Tube Concept Builder (can be used for closed tubes as well)

Document here, preview below

AP Free-Response Practice, Skills and Metacognition
Activities · Teaching Methods

AP Free-Response Practice, Skills and Metacognition

Marianna RuggerioLeave a comment

It’s been two weeks since I got back from the AAPT Winter meeting inVegas and I’ve barely had time to sit and reflect. I’ve made some big changes this school year. Exactly one year ago I interviewed for the AP Physics position in a new district. It was one of the more challenging decisions I’ve needed to make in my career, and the first time I was walking into an interview fully confident of who I am as an educator, what I want in my future and in complete control. (When I took my position at Auburn I was confident, but hadn’t yet taught an AP course). With a new position comes new challenges and adjustments, but a new position paired with experience and confidence also brings the opporuntity to recognize challenge for what it is: an opportunity to search for innovative solutions. That’s one of the best parts of teaching; getting challenged in ways that require creativity.

With challenge comes a heavy mental load and so when the deadline came around for the AAPT abstracts I quickly threw together an abstract related to holding students accountable when we do work a la Building Thinking Classrooms (Accountability on Ungraded Homework) but had only shared here on the blog. A part of me felt pretty lame as this particular idea didn’t feel as exciting as I thought it should be for presentation, but I’ve learned that we are typically our own worst critics, and it’s always valuable to go ahead and present anyway. (Here are the presentation slides)

As it turned out, my session was loaded with three other awesome talks that all complemented one another really, really well. Aaron Titus talked about his “how to test better” workshop which is secretly a “How to Learn” workshop. Another faculty member talked about standards based grading at his college and Kathy Willard at Case Western talked about some metacognitive work she’s engaging students with. This session, tied with the AP sessions that took a deep dive into the science practices got me thinking about how to put all of this together to support my students.

The result? An FRQ reflection form.

Part of this spawned from the fact that we had -30 windchills last Friday and a remote learning day. With remote learning obtaining student feedback is more critical than ever for me, but I realized this would be a good strategy to maintain for all FRQ practice.

The Process

  1. Students complete an FRQ alone under timed conditions
  2. Students flip their work upside down and move to vertical whiteboards. They are permitted the next 15 minutes to discuss the problem and they can whiteboard their work/discussion as they go. This is a riff on friends-no-pens due to the complexity of the problem.
  3. As students wrap their discussion, I ask them to consider how the points are distributed.
  4. Students return to their original work and have 10 minutes to revise/add to their work. The way my room is set up students CANNOT see the work on the whiteboards
  5. Students self-score the FRQ. I ask them to give themselves a first pass and second pass score.
  6. Students complete the reflection

The reflection is a google form. The nice thing about this is that in addition to collecting this data easily, I can link multiple forms to the same spreadsheet to track changes over time.

The Google Form Reflection

This first part is asking students to think metacognitively in a few ways. First, I want them to see the gap between their individual and group-think. In a highly collaborative classroom, sometimes students think they have a better handle on the material than they actually do. The first pass at the FRQ gives them a chance to see what they are capable of alone. The second pass allows them to see that they can and do understand more physics than they might give themselves credit for, but it’s not currently encoded in their long term memory. This gives students a place to identify as a study need.

Next, I use the standards information available in AP classroom to provide students a check-list of the skills that were assessed. I ask them to identify both what they did well on and what they did not do well on.

To wrap it all up I ask a final question to get a guage on what my students believe they need more of.

Looking At Results

Below is a snapshot of some of my student results and reflections. I sorted the original scores from lowest to higest so you can see the improvements. This was a Translation Between Representations question which is worth a total of 8 points.

First, observe how much scores increased from original to group think! But what I think is particularly important is that this work happened without access to notes of any kind before and after conversation. When students return to their papers they no longer had access to the whiteboard work.

Next, I think some of the “aha” moments are particularly important and poingnent. I especially love the first one that is more about testing strategy. (This particular student is a rockstar, but the physics assessments have been rough for them).

I thought this data was particularly interesting:

I think anyone who teaches AP knows kids dread the word “derive” like we’re asking them to be Einstein Geniuses (more on that in another reflection another day). Interestingly, my students reported that they all need help on derive, but actually my data from AP classroom and testing informs me that functional dependence is actually one of their weak spots. And yet, students aren’t overwhelmingly identifying it as one. I’ve determined that this particular blind spot is going to be an area of focus these last few months as we enter the final lap.

Asking students where they struggle is always telling regarding their thought processes. Currently many of my students are still stuck in a very algorithmic way of thinking/approaching physics rather than working big picture down and it remains telling in their responses. This is still really valuable information because in order to get students where I need them to be I need to meet them were they are at first.

I revised the cannon launch!
Activities · Teaching Methods

I revised the cannon launch!

Marianna RuggerioLeave a comment

In my last post I talked about how I finally reenvisioned collisions and explosion problem solving for my on-track physics. It went so well I’m definitely going to integrate more of it into AP.

The goal of the reenvisioning was to set students up for a meaningful tennis ball cannon launch lab at the end of the lesson sequence.

If you’re unfamiliar, you create a tennis ball cannon, launch it, and have students calculate some quantity based on momentum conservation. To be honest, I haven’t run this lab since my first few years teaching for a few reasons. One was that my cannon got stolen at my first job. Then I decided that whole class labs are less effective than small group work and I hate when it looks like everyone is copying answers. The activity just wasn’t meaningful enough.

But after talking to several friends, everyone was excited about the idea of a cannon launch, so I spent my weekend rebuilding a cannon.

To open the lesson I set up and demonstrated an “explosion” with our car-track system. I ensured that one car had more mass than the other and we had some conversations about what to expect. We also talked about what the equation would look like based on our previous experiences with elastic and inelastic collisions. Students were able to correctly determine that it’s basically the opposite of an inelastic collision.

Next, I gave them the scenario where the cannon had a mass of 4.0 kg, the ball had a mass of 1.0 kg and the cannon’s launch velocity was 5 m/s. These numbers were strategically chosen. I wanted to keep whole numbers and also have a cannon-ball ratio that was similar to the actual cannon-tennis ball.

Students then completed the four representations as we’d previously done earlier in the week. Below is a student work sample.

The great thing about this was that students were able to accurately represent and predict the outcomes of the cannon-ball system before we got into the muck. This got students thinking individually and talking in small groups. We also discussed why the results made sense.

To launch the cannon I let it go through a photogate to snag the post explosion velocity and then students completed the calculations.

For the post-lab analysis I threw in a few thinkers. They included:

  • Find the average force on the ball
  • How would a longer cannon change the ball’s launch speed? Explain in terms of impulse-momentum
  • If we used the same cannon but filled the tennis ball with rice, what would happen to the speeds of the ball and cannon post explosion?

You can see a sample student response below:

These questions led to some really great conversations that brought us back to equal forces, equal momentum changes and where time falls into the mix.

How I Teach… Forces (Intro, the Observational Experiments)
Activities · Teaching Methods

How I Teach… Forces (Intro, the Observational Experiments)

Marianna RuggerioLeave a comment

The first set of posts I wrote for this series was about momentum because I made such a large shift from how I used to teach to how I currently teach.

In the same vein my teaching of forces has also changed.

In the past my force unit looked like this:

  1. Inertia Day! Lots of Demos, initiation into the inertia club with club cards (you hold the card on your index finger with a penny on top and figure out how to flick the card out from the penny)
  2. F=ma. Define it, notes, define force diagrams, practice force diagrams. Practice F=ma problems.
  3. One day on action-reaction. Gloss over it; “it’s easy”

I cringe writing this out now. It was so boring! Inertia and action-reaction felt like fluff. We don’t need fluff!

Currently, my unit structure is designed with the big ideas in mind. (Because, tenet 3: Order Matters, Language Matters) I was excited to see that the idea that teaching in a structure that models the thinking we are targetting to improve outcomes is actually supported by research, so my model draws on Lei Bao’s frameworks for force:

One of my biggest frustrations was students putting random “F(applied)” on force diagrams. It irked me to no end!

So starting with the framework for Newton’s Third Law, I turned my force unit on its head. The fundamental piece we begin with is:

A force is an interaction between objects

Observational Experiments

We start with the activity from Pivot Interactives where two cars collide.

Students are asked to separately write what they observe about the car motion and also what they observe about the force acting on each car.

After making the observations we discuss.

The primary aspect students recognize is that heavier/faster cars result in bigger forces. That’s all well annd good, but what about the force that each car experiences. Even though they’ve literally just witnessed and recorded it, they still want the heavier one to hit harder than the light one within the same collision! We closely observe this together and see that, indeed, the forces are always the same.

This is what allows us to define a force as an interaction between objects. Without a second object pushing on the ring, the ring won’t squish. Since the force is something that happens between, it must be equal and opposite.

This very small shift has been a game-changer. It is very rare for me to have students putting totally random forces on objects because “it should have one”.

From here we dive into Eugina Etkina’s ISLE cycle.

Students are asked to hold a heavy and a light object in each hand, palms up and then represent those objects with arrows on a diagram. Students are asked to label each arrow with the object interaction. This is a fun one because a lot of kids are quick to label “gravity” but when I inform them that gravity, is not in fact, an object, they have a moment of pause. Eventually all students arrive at the correct diagrams: equal sized forces on each object, bigger forces on the heavier object.

From here I diverge between AP and regular physics. In regular physics we will go directly to the mass vs weight lab where students will ultimately derive the expression F(earth) = mg. With AP we continue to follow a modeling cycle with experiments with a bowling ball down the hallway: rolling, constant force forward, constant force backward. Then I ask how we could have constant velocity AND constant force. Students are quick to say “push down” (and we are fresh off of projectiles where x and y are independent!). Then realize if we alternate “taps” that will do it (balanced forces). Students are asked to represent and reason by drawing a complete motion map, an accompanying force diagram and then look for patterns. In this way students then recognize that balanced forces will result in constant motion (including v=0) and unbalanced forces result in accelerations. For homework students will complete two exercises from the Active Learning Guide from Etkina’s book where they will continue to practice drawing motion maps and force diagrams together in order to find relevant patterns. From here we get ready for labs!

Up next… labs labs and more labs!
Quantitative Experiments with Forces