In My Class Today · Teaching Methods

I did something I would NEVER do in most classrooms

Anyone I have spoken to one on one knows that my group of AP Physics C students is truly a unique group. They are the kind of group that comes around once every few years and makes your teacher heart soar…so you bring them up with you and cast them off and they fly higher than even you could have imagined.

So I thought I’d try something radical. Work on a skill that was far greater than their ability to do physics. I wanted them to focus on the learning process.

We are starting the Biot-Savart Law. Students need to do the derivations for a line, ring and ring segment of current. The reality is that the math skills are no different from anything they haven’t already seen before. But as we know, often times when students are presented with a new application it’s like everything they’ve learned is back to zero. The reality, of course, is that they lack the experience and mastry to be able to make those connections as we do as teachers. So I assigned the reading several nights ago. I asked students to take particular note of the three examples, and then I assigned the students in groups to one of the three examples.

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The paper they received, however, was not a carbon copy of the book’s example. Because we know what students do when we ask them to read. They skim. They decide they can understand how the author got from step 1 to step end and they move on. But we know if we asked them to do a similar problem they would barely know where to start. I wanted them to actively engage in the material in the text. So I told them they had to prepare their assigned problem to teach to the class, instead of me teaching it.

Students had 2 nights to prepare plus 30 minutes to discuss in their groups the day before. Today was presentation day.

Imagine your first year teaching and that lesson you thought you’d be fine at, so you didn’t quite prepare it the way you should have. That’s what happened. But it was ok because I knew that all of my students would be ok. They challenged each other, they forced the students presenting to slow down, they asked the necessary clarification questions that required the presenters to really think about what they were doing rather than regurgitating text.

After the group had come to the end, I stepped in. I asked the group to step back for a moment so we could summarize (because we all know what happens when we get lost in the details and the mistakes…) I asked the students to explain why we did each step and connected it to what they had seen before. If notes or annotations needed to be added to the board, we added them. Once we were certain everyone was securely on the same page we moved on.

At the end I explained my goals of this exercise  to my students. Not only do I want them actively engaging and learning (and seeing you CAN learn) from the text, the reality is that since they are ALL pursuing STEM majors there is a VERY REAL possibility that they will each be in a teaching assistantship in the next 3-5 years. They are going to need to learn how to teach what they are comfortable with, what they may not have been comfortable with, or something they learned 4-5 years ago. These teaching and communication skills are so valuable and go well beyond the world of academia.

I almost backtracked on this assignment and took over today, but I’m really glad I didn’t. My students once again rose way above and beyond what I expected. Working with a group of gifted AP Physics C students can be really challenging because finding the sweet spot of struggle vs overwhelming is a lot higher than one might anticipate, and in this course I think that sweet spot is higher than even the students realize. But that sweet spot is where the largest amount of growth happens, and I think we hit it today.

Classroom Issues

Physics Teacher Shortage? Not so Sure

“You will be SO markatable”

“You will have NO problem finding a job”

“You’re certified in physics, chemistry AND math?! You can get a job anywhere!”

Those comments have all been said to me. Because, you know, I have a physics degree, I’m a woman, and I have a pretty cool set of experiences. And yet in 2011, when the recession hit the teacher landscape, I found myself sitting in over 20 interviews with no success. I spent the next two years working as a tutor after being rejected from the physics teaching job at that school and also teaching math at night school and chemistry at summer school. I was also teaching summers and Saturdays at Northwestern’s gifted program. All of these things together plus private tutoring scrapped together a decent salary. But after 20 interviews and no success getting a full-time teaching job…I won’t even get into what that did to my feeling of self-worth, especially when I caught a student from summer school telling her classmate about me, “she’s not even a REAL teacher”, a day after which her mom showed up “lost” so she could scope me out.

Here’s a snapshot as of right now within a 50-mile radius of where I live

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That’s right! One job. And guess what is under the job description “chemistry endorsement desirable” Yep. This is not a 100% physics job. This is a physics job with a chemistry prep.

Mind you, there is no shortage of people here! My city is just under 150,000 people and our public school system consists of 5 high schools. There are numerous private schools in the area representing the Catholics, Lutherans and several other Christian denominations. There is one teacher in each building who teaches physics and I am the only teacher who gets to teach physics all day. I am also the only teacher with a degree in physics. (I am part of the 12% nationwide that’s a woman physics teacher with a degree in physics) The second sentence is the one that seems to get all of the attention by Universities and PER groups.

APS put out this report which doesn’t quite sit with me right. You see, they reported these findings, among others, regarding why individuals want to and don’t want to teach:

“by far” as the report mentions, the number one reason why individuals don’t want to teach is because they fear “uncontrollable or uninterested students”

The minute I saw this I questioned the results. WHO ON EARTH are they talking to? Well, APS, you got me to check out the whole report. Here’s who they surveyed:

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Only 64 people who completed the survey are committed teachers of high school physics! Most everyone else involved was currently within the University setting (students).

Newsflash: You have NO idea what the classroom is like until you get there. Betsy Devos is a fantastic example of this.

Turns out, when you put a person who’s mildly competent at teaching and cares for the craft, the ‘disinterest’ and misbehavior are rather subdued. Make no mistake: it takes 3-5 years to get into a groove and to start to master the management aspect, but that can be said of most any job.

The report also discussed the various incentives people are given to go into teaching:

1. “Access to high-quality courses at my institution that prepared me to be a successful teacher.” 2. “All my student loans could be forgiven if I were to teach for 5 years.” 3. “Better teaching salary.” 4. “I would not have to spend extra time in school to obtain a teaching certificate.” 5. “I would be given free tuition for extra time spent obtaining my teaching certificate.” 6. “There are currently scholarships available for people in science and math teaching certification programs. Scholarships up to $20,000/year are awarded on the condition that, after earning a certificate, one teaches two years in high-needs areas for each year of financial support.”

No surprises here, but every single one of these is an extrinsic motivating factor. While usually somewhat effective in getting the ball rolling, it is hardly sustainable when the rubber meets the road and the nitty gritty nastiness of this job break forth. And let’s be real here, if it’s money that motivates you and you’re smart in the sciences, it doesn’t take too long before you realize an engineering job in the private sector is going to let you pursue your passion AND be up for raises AND get you 6 figures a lot faster. (and you get to pee whenever you want).

I would like to posit that there are three things that need to happen if we really care about highly qualified teachers in STEM

(1) We need to devote SERIOUS time, energy, effort and money into the teachers who care about their craft of teaching and get them the support to teach physics well. PhysTec is trying to do this and is providing amazing opportunities for teachers. We need more of this. New Jersey also implemented teacher training to boost physics in their schools. They actually see physics as the gateway to STEM careers. Turns out, the results were amazing. Not only has physics enrollment boomed, it has boomed amongst minority students, and their AP scores have boomed along with it.

(2) We need to advocate for physics and STEM education outside of our STEM bubbles. Too many of us are like our students, solving the problems we already know how to solve because it feels good. Telling each other about the importance of physics makes us feel good, but how much of that is getting out to the public? To parents? To students? To board members? To administrators? To politicians? Here’s an example of the difference in two districts:

District A has a strong STEM program, including an exclusive engineering academy. District A historically has offered Conceptual, Regular, Honors, Engineering and AP Physics C. There are 11 teachers who teach physics at some point in the day and although physics is not a graduation requirement, it is a norm that all students take physics before graduation. Since district A does not offer AP Physics 1, parents band together to ask the administration to run the course so that students who want to take an AP Physics can, even if they are not engineering bound. 

District B has a weak physics program and would like to promote more students taking AP courses. However, district B refuses to run a course if less than 24 students enroll. None of the schools in the district are able to offer AP Physics. AP Biology runs sporadically. One year 20 kids signed up for AP biology but the district said this number was too small and canceled the course. Infrastructure is falling apart and although there is a 10-year facilities plan, staff have been told that they will only consider re-evaluating science rooms when they see if any money is left over. 

These kinds of things go on all over the country. The simple matter of fact is this: unless a district is well-endowed with funds and/or parent advocacy, STEM is not supported on a very basal level. Because STEM requires space and equipment, which requires funds, and requires a continuous influx of funds in order to maintain the space and equipment and up to date texts.

Most of the folks way up high in school systems are pretty clueless when it comes to the needs of STEM classes. It’s not their fault, but if no one is truly advocating, they have no reason to funnel funds in that direction

(3) Our current physics teachers need to feel valued. They need great mentors. They need networks. I was really fortunate to have this “growing up” my AP Physics teacher was huge on intentional mentoring of rising teachers, he introduced me to Physics Northwest, which got me tapped into AAPT. From there I developed an amazing network of Chicago teachers. One of the teachers I met through this network, Shannon Hughs wrote an article in The Physics Teacher about the importance of this mentorship. Shannon probably doesn’t remember this, but at one of my first PNW meetings, she was sure to come up to me and tell me about an opening at her high school. The manner in which she approached me stood out and I regretted the fact I had accepted a job already. She was already putting to work what she had learned from her mentor. Then I moved an hour and a half away from Chicago and I lost this network. After 5 years of living out here I discovered the amazing community of #iteachphysics on twitter. It is these communities and mentorships that re-invigorate my passion for teaching.

Here’s the deal: no one goes into teaching for the money. We go into it for the passion. The passion of our subject, the passion to invigorate our students, the passion to see others learn and grow. The best teachers are these people. You can’t train that and you can’t crank that out of any big PER study or think-tank group. But there’s a catch…if I can’t do my passion every day, why would I stay in it? For me, it’s because my passion for teaching and students is greater than my passion for physics. If it were the other way around I probably would have finished the MS in electrical engineering I started in 2013 and I would be working in the industry now. Yea, that’s right, I was almost one of those numbers who left the field. Because the reality was that the field left me. I was moving to a place with no jobs and I had a department head who was almost begging me to join the department (this is a much longer story than is appropriate for this blog post). I am incredibly fortunate that I am in the position I serve now, it is literally everything I have dreamed of doing.

Pushing a bunch of physics undergrads into becoming high school teachers with extrinsic motivators is only going to create two things: teachers who lack the true empathy, patience and motivation to serve a student population and a bunch of graduates who think there’s a million jobs out there when actually there are just a handful. If they land one, chances are they won’t teach physics all day. In 2014 I taught 5 sections of Earth Science with the promise that if I took that job I would have physics the following year. I love teaching, but when I got those physics classes in 2015 after not being a physics teacher proper for 4 year, it was incredible how my motivation and job satisfaction sky-rocketed.

The very real fact is that physics is still undervalued. Everyone assumes it’s too hard and unnecessary. Much like the “Oh I never did well in math” statements that can cause math anxiety in children. Every kid who walks into my classroom walks in with fear and dread because they have heard horror stories. And yet, if they talk to any single student who made it past October, the critical 10-week learning curve, that student will tell you “it’s hard, but it’s fun” or “it’s hard, but you just have to think about it” I fight these preconceived notions tooth and nail every day, but when adults everywhere are telling them otherwise, they have no reason to believe the physics teacher that physics is a good place for them to be.

Concept Modeling · In My Class Today · Teaching Methods

Pass Along – Modeling Waves

The pass along activity is one I developed shortly after attending a Kelly OShea workshop. I wanted to combine modeling with the strengths of white board speed dating and board walks. At the time I didn’t have the large whiteboards and for this particular activity I decided a piece of paper would work best.

Students have already done a reading on waves ahead of time (hopefully).

Part I: I ask students to draw in a pictorial representation of what a longitudinal and a transverse wave might look like.

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This is inevitably the most common drawing. Students obviously did the reading, but struggle with a pictorial representation

Students are then told to pass along their paper. I predetermine groups randomly for this activity. Three is best, but if I don’t have a factor of 3 then I put the stragglers into groups of 4. It looks like this:

Student 1 -> Student 2 -> Student 3 -> Student 1

Part II: After students have passed along, they are required to look at the work done by their peer and explain, in words, why that person drew what they drew. Much like speed dating, this requires each of the students to get in the minds of their peers, but without the opportunity for their peers to explain.

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Students then pass along again.

The third person takes a look at the previous two answers and then has to think of a way to model each wave type with their bodies.

After the three pass alongs, students get into groups, at this point each paper has been touched by the same persons. They discuss their answers and then they have to get up in front of the class and model with their bodies each wave type.

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The physical modeling is great in that the kids are up and moving, but it also provides an opportunity to have a discussion about the model. 7th hour we had a discussion about whether or not doing the worm accurately models a wave (nope, the particle is moving across the room). Similarly, I had a few groups move their whole line down the room which brought up the discussion point about what a wave transfers and doesn’t transfer.

Afterwards, we will go out as a whole class and model transverse and longitudinal waves using an 8-step count.

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A unique representation of a longitudinal wave I hadn’t seen before
current news

17 Lives is the Only Thing That Matters

There are certain times where I feel strongly and deeply about an issue and trapped at the same time. This week is one of them. There is an unrelated post sitting in my drafts in part, because I have considered making it a vlog post, rather than a written one and in part because I know how it will be received. At the core of that message and this one is one thing: exhausted frustration.

I am tired of every issue being an either/or and I am tired of every politicized issue meaning one part of one thing in one party and a different part of the same thing in another. Why is there no party that simply cares for people?

As the human race, as the most advanced, complex, highest-order being on this planet, we are wired to lean on each other and to sacrifice and care for one another and to do so with empathy.

The tragic school shootings are not an either/or. This cannot be mental health/parenting/reporting vs gun laws. It’s both.

I have contention with some other either/or issues split down party lines, but that is another post.

None of the problems we are faced with are going to be solved by arguing each other and blaming a single issue. The only thing we can do is come together, accept the brokenness of humanity, the brokenness of our laws, the brokenness of our systems and consider for just a moment that maybe there are aspects of both arguments that are wrong and aspects of both arguments that are correct. At the end of the day, there is one truth: we need change and we need action.

17 people died this past week. Hundreds of their loved ones, friends and peers have been irreparably affected and the social media world blows up with the classic arguments, inevitably tearing each other down insisting the other side is wrong.

17 people died and the rest of the unaffected world is at each other’s virtual throats over the right thing to do.

17 futures stopped Wednesday and too many of us are now consumed with a personal conviction that aligns to a political party and are more concerned with the future of our followers than the lives directly impacted.

This is not happening worldwide, and so yes, we are doing something wrong. It’s time to take a step back, swallow our pride, and come together and be human.

 

Teaching Methods

AP Physics C in the Accelerated Classroom: Addressing the Needs of the Gifted and Talented in Physics

Gifted and accelerated learners have specific needs in the classroom that frequently go unmet. It is a grievous error to assume that just because a student is gifted they will be successful. Differentiation is often viewed as incredibly labor-intensive on the part of the teacher with difficulty in grading different products fairly. This is of particular challenge in the current Advanced Placement (AP) Physics C program since, under the college board recommendations, many physics C students already have a strong foundation in mechanics from AP Physics 1 (algebra-based). This paper will share a particular example used in the lab in an AP Physics C gifted classroom and how the products are easily differentiated and scored in a fair manner.

 

Introduction to Gifted and Talented Learners

The first thing that must be noted is that gifted learners exist in every classroom. The second thing that must be noted is that gifted and talented looks different on each individual. Additionally, when students are put through an identification process, minority and English language learner students are overwhelmingly unidentified.

Identification of gifted and talented students is immensely important because research has shown that in the absence of the ability to nurture student talents, many of these students will, in fact, underperform. Students are either placed in environments that lack rigor and challenge and so they disengage because they are bored, or if the teacher identifies the student as “smart” the teacher often does not recognize specific markers of giftedness that contribute to student behavior in the classroom, prohibiting the teacher from allowing appropriate accommodations.

It is important that every classroom teacher become aware of giftedness so that they can best address their students. Much in the same way that we will readily allow a student with ADHD to stand during class, or use a fidget, we must also recognize that gifted and talented students have their own set of needs to be challenged and to grow.

Although there is no one blanket description for students who are gifted and talented, there are some unique markers. Much like a student who may be diagnosed with a special need, gifted and talented students’ brains are physiologically different. They have a thicker pre-frontal cortex that develops differently from their peers and they, in fact, have more and stronger neural pathways than their peers2. Not only do they think differently, they perceive the world in a different manner. In the absence of development of talent, gifted individuals can lose the strength of their pathways, rather than expanding them.

One of the most clear differences in gifted students is that they exhibit one or more over excitabilities. Overexcitabilities describe a series of traits and/or behaviors that gifted individuals feel on a level that is far more intense than the general population. These include the following: intellectual, emotional, psychomotor, sensory and imaginational. Intellectual is what people are most familiar with when they think of giftedness: avid readers, love of learning, independent thinking etc. Emotional are the students who often have an overwhelming sense of empathy for their friends and family. Due to this they are often the ones who will take up causes for advocacy. They also may exhibit extremely intense anxieties. Individuals with psychomotor over excitabilities are often misdiagnosed as having ADHD, they may talk fast, act impulsively and seem to run on little sleep. Sensory have a heightened sense in the five senses, they are often extremely interested in the arts and have a depth of interest in aesthetics. They may also, however, be unusually sensitive to smells and tastes. Individuals with imaginational overexcitabilities are the ones who are constantly daydreaming, visualizing, Males tend to score higher on the intellectual and psychomotor areas while females tend to score higher on the emotional and sensual over excitabilities3

AP Physics C for the Gifted and Talented

Acknowledging these needs for gifted students, what is a teacher to do? Two of the most important tools are acceleration and differentiation.

We often think of acceleration as grade skipping. While this is useful for many students, it is not in our grasp as classroom teachers. We should, however, not prohibit say, a sophomore, from enrolling in physics if they have met the appropriate math pre-requisites. Surprisingly, acceleration at the grade level has shown to somewhat close the gender gap in publication and salary for female students4. At the classroom level, where we have control, this means compaction of curriculum. I lean most heavily on this for my students.

Since the students in my class have all taken AP Physics 1, they have an incredible depth of conceptual foundation as it relates to mechanics. This was, indeed, the goal of the revised course. The challenge now, however, is to make AP Physics C exciting, interesting and challenging. At the same time the goal of any high school teacher should be to equip their students with the foundation for the skills needed in college.

For any STEM field, we know well that lab skills are indispensible. At the same time, we also know that creating a genuine lab experience when students have little to no lab experiences is extremely challenging. There is a certain level of base knowledge needed to have a valid lab experience from start to finish. Fortunately, students in AP Physics C have already obtained that base knowledge. The only difference is that now my students are required to incorporate calculus.

 

The Flipped Accelerated Classroom

I operate on the premise that first, the majority of the physics concepts should be review, and second, the lab experience is the most important experience in my classroom. While it is not imperative to student success that they be able to determine an obscure moment of inertia, it is imperative that they enter college with a basic skill set that includes troubleshooting, use of basic equipment, creativity, critical thinking and problem solving strategies. On the first day of school I gave my students the following assignment: design a product that demonstrates to me that you have mastery over all of the AP learning objectives for kinematics.

Immediately this assignment is differentiated: students have almost endless choice. They have full access to all lab equipment plus anything else they would like to use or bring in. This is, at first, an extremely challenging prospect to students. They are not used to having so much choice, their activities have more or less been dictated by the goal and/or equipment available. This is not true of real research; in that case you must select a project, investigate, and produce results.

We recently did the same with momentum. Since this topic is much more in-depth than kinematics, I assigned nightly homework sets and provided solutions the following day. The homework was not collected or scored as I am leaving it in the student’s hands to determine how much repetition is necessary for themselves. In this unit they were asked to design a lab in which all of the objectives are present. Since this project would inevitably include many other topics within mechanics I provided a little bit more guidance, encouraging students to start with a question. Within the first class period I had a group investigating a buoyant object dropped into a container of water (Fig 1)

and analyzing with Vernier VideoPhysics, another group analyzing the deflation of a balloon attached to a string with a straw, a third looking at spring pendulum, and a fourth examing a dynamics car attached to a spring on a horizontal surface. Each of these involved a varying force (not a requirement, but an option for the exemplary plus mark) and in the case of two of the experiments, students needed to study topics they had not yet covered as it related to their problem.

Student Products, Evaluation and Presentation

Student products vary n terms of level of complexity and interest, but they have always been exciting to grade. The first challenge, naturally, is scoring the product in a way that is fair for all students, given the large variety. To this end, I grade the products based on how well they meet each of the objectives, from Exemplary to Unsatisfactory. In order to permit students who are more mathematically advanced or who would like to go for the challenge, I include an exemplary plus category. At the beginning of the year this category was for any correct application of calculus, once the year progressed this category needed modification to ensure the same level of challenge.

Students are also expected to present their results and provide feedback to their peers. We do a type of poster presentation session. Students put their procedure, lab design and results on a large whiteboard. (Figure 2) , one partner circulates the room while the other remains at the board to present to their peers. During this time period students are to ask one another questions, whether it be for clarification, or as a way to offer a suggestion. (Figure 3) After students have moved through the room, original partners move together. The partner who circulated initially now must explain each board to their partner. As they do so, they are asked to leave feedback on a smaller board. At the end of this exercise, groups return to their boards and review the feedback. I then give students another few days to make adjustments and corrections before turning in the lab.

Applications for the Mixed Classroom

Allowing student choice and differentiation for gifted students is just as important as allowing other students extra time on exams or the ability to use a fidget. The reality is that just as our classrooms often will have students with special needs due to a disability, we likely also have a non-zero number of gifted students as well, who’s needs must also be met. In a mixed classroom, this might mean generating both the guided and open-ended lab. The modeling curriculum works very well for all students, but the differentiation component is key. Gifted learners should be permitted to do less repetition as long as they can prove mastery. They should be permitted to work together in class sometimes (ability-based grouping), rather than always grouped with the struggling students so they have the opportunity to flourish with like minds, much as we appreciate upon entering college.

 

Conclusions and Benefits

This type of activity and assessment has served multiple purposes. First, it allows for differentiation within the gifted classroom. Students have the ability to make their products as simple or complex as they determine, while still meeting the learning objectives. Secondly, it requires students to make a variety of considerations and assumptions such as which equipment will be best, how to control for a variety of variables, and which variables can be simplified due to assumptions or uncertainty measurements. (For example, in my group that examined the deflating balloon, they massed the weighted balloon on an extremely precise scale and noted it was loosing mass, even while tied. ) Students are using and improving on lab skills and techniques. Lastly, students are learning the importance of clear communication and critical evaluation. In a time where even undergraduates are expected to produce publishable research, communicating, evaluating and responding to evaluations become ever more important skills. By focusing on these at the high school level, students become better equipped for whatever their future holds.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Uncategorized

Encouraging women in STEM: What is a teacher to do? (I got published!)

This spring will mark 10 years since I stepped foot in the classroom as a student teacher. It’s always difficult for me to wrap my head around that length of time. By the 10-year mark, it would seem reasonable that a teacher could feel established and start making her way toward mastery…and yet, I still feel like a first year teacher. Due simply to life changes I have worked in five different buildings spanning 3 districts, on 2 sides of the state and have never once had the same set of preps. Only in the last two years have I felt I had the opportunity to truly build and grow a program and the students along with it.

The past two years have also been what can only be described as a special and unique experience. I had a phenominal group of students genuinely interested in the subject matter. So much so I managed to convince three of them that majoring in physics would be a great idea. All three are female.

My breadth of experiences has made me take a very critical look at what encourages student choices and what discourages them. I think too often we attribute outcomes to interest and drive, rather than inspiration and grit. I also firmly believe that while interest and drive are outside of my control, inspiration and grit are within it.

When I ran across a book review discussing a woman’s in a man’s world, specifically a “boy’s club” it immediately inspired me to write and share my experiences to expound on the question, “what do teachers do?” The answer to that question is far more multifaceted than one concluding sentence can contain.

My thoughts were accepted for publication in The Physics Teacher for the February edition, and I’m so thrilled!

http://aapt.scitation.org/doi/10.1119/1.5021425

 

In My Class Today · Teaching Methods

A Spin on Energy

Last week I ran a pretty straightforward lab:

  1. Put 120cm of hot wheel track into a design of your choosing
  2. Run a ball down the track
  3. Record velocity with a photogate
  4. Repeat at 10-12 locations
  5. Plot the energy curves.
  6. Plot Translational vs Rotational Kinetic energies and find the rotational inertia constant.

 

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Sample track set up

 

Students should see a transfer of kinetic and potential energy which makes sense. Of course, students should also expect to see a decreasing total energy curve because of friction constantly taking energy from the system.

I had two fun surprises I got to incorporate:

  1. The shape of the TME curve

Inevitably this curve had a particularly sharp drop off at one moment in time. I had students sketch their tracks on their whiteboards in addition to their lab results. IMG-2087IMG-2088Do you notice anything? The largest drop off in TME corresponds to the moment where the ball is at the bottom of the hill. This serves as a great review of work and circular motion. Frictional force, as we know, is dependant on normal force. The normal force of the track changes and corresponds with its shape. We can actually predict the drop-offs in TME based on shape and even determine the work done by friction.

  1. A group with “bad” data.

Their data wasn’t actually bad, they obviously had forgotten something when they set up their formulas in the spreadsheet. But was there a way to find this without redoing the whole data spread? Absolutely. After creating a large circle to share whiteboards, we honed in on the group where the TME curve was mirroring the potential energy curve. The rest of the data seemed good…there was an obvious trade-off of PE and KE…although the curves weren’t as high as they should have been. So what was the problem? I selected a student to draw in where the energy curve should be, based on the shape of their track and everyone else’s data. She drew in the curve. Next, I asked students to note where this curve was and where the PE curve began. It was at 0.3 J with PE starting at 0.6 J Then I asked them to note where the KE curves were at… they were at 0.03 J. Notice anything??? They were off by a factor a 10! Where could a factor of 10 be? Did they forget a 9.8? Did they convert grams to kilograms properly? cm to m? Upon examination of their equations, they found the missing 10 and…TA-DA! Fantastic results.

I think it’s really important to note the value of both exercises. The lab itself was relatively simplistic, but it lent itself to fairly complex conversations.  I think this is especially true for the group with the “bad” results. How often do our students present with this and either (1) Default to “well my data must be bad” or (2) Start from scratch, rather than locating the mistake? In this way, students were able to critically analyze, strategize and problem-solve. It turned out to be a really easy fix.

Oh and the slope of the translational vs rotational KE? Yea that came out to 2/5….exactly. That’s super exciting!