The Very Spring and Root

An engineer's adventures in education (and other musings).

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From the Classroom

Feeling Teachery

I have survived.

September and October were pretty grim months. After a honeymoon period that lasted a little less than a week, I began a steady slide into some of the hardest weeks of my life. As my freshmen felt their high school jitters wear off and my juniors had finished scoping out my weaknesses, the real battle for sanity began.

It wasn’t until the last couple of weeks before the winter recess that I truly felt like things were approaching a modicum of stability. I’m still tired, but I think that’s normal. I have no idea how the rest of the year is going to go, but I can at least reflect on the last four months.

Looking back on it, I think I can reconstruct a few lessons learned for any future new teachers.

1. Nothing else matters if you cannot control your classroom.

I know, you’re a stubborn idealist and waiting to get started reforming education for a future enlightened democracy. But take the high-minded ideals about liberating education and democratic classrooms, the bold plans for discussion-based inquiry, and your folder brimming with ideas for weekly project-based learning, and set it aside. At least for the first few months of teaching full time.

Instead, attend to the basics and make sure you have them down pat: Clear rules and expectations, with ready short responses for the inevitable “why?”. A posted chain of consequences that you will stick to with no exceptions. A plan for how you will hit your educator evaluation targets. The first two weeks of lessons planned (not just bulleted, PLANNED TO THE DETAIL) in advance.

And, critically, an airtight system for organizing paperwork by graded/not-graded, which block, handout-and-keep, handout-and-return, late work (and associated penalties), late work due to excused absence, makeup work, makeup exams, answer keys, advisory, notices to students from administration, extra credit, extracurriculars, and every other type of document you can think of… because the paperwork will come in a flood and it will never let up. Ever.

Once you have a consistently safe environment for learning that doesn’t make you feel like you are drowning, then you can move on to bigger and better things like those inquiry-based project discussions.

My residency year was spent at a great school with great students that taught me a lot about many things except what I now believe is the single most important skill: solo classroom management under constantly adversarial circumstances, all day every day week after week.

If you are unsure how to get started, I recommend Rick Smith’s Conscious Classroom Management as a reference that helped me out immensely.

I’ll say again: NOTHING ELSE WILL WORK if you cannot control your classroom. It has only been quite recently that I’ve felt confident enough to move much beyond making sure that basic goal is met.

2. Steal everything.

I still haven’t quite internalized that I really do not need to homeroll every little part of my curriculum and logistics. Stop reinventing the wheel, use what’s already out there, and ramp up your own style slowly over time. I’ve got years and years to hone my own style and invent my own methods. I don’t need to do that in the hardest phase of my teaching career.

As a first year teacher, it will not be resources you need. There are hundreds, if not thousands of great resources on teaching, education, science, inquiry, labs, etc. People still keep trying to give me workbooks, websites, curricula, and lab equipment that I will put in my back closet and not look at again until next summer. What you will really need is time, which is the one thing no one can give you more of. You need to make more of it yourself (where possible) by choosing how you will approach your work.

3. Families are your best allies.

Even my most difficult alpha-males, the ones who seemed to be hell-bent on locking horns day after day, were just looking for evidence that I will provide a safe and secure environment. Getting families on board with that plan is a good way to convince those students that a) you care, and b) you will not be letting them off the hook. Further, calling home with compliments gives them positive incentive to perform well. Deep down, all kids want to succeed and be seen as successful, even if they do not want to admit it.

4. Make time for your support network.

They say the first year of teaching is the hardest year, and the first quarter of any teaching year is the hardest quarter. It stands to reason then, that the first quarter of the first year of teaching is a double dose of difficult. There is absolutely no reason to go it alone.

I went through Boston Teacher Residency. Its cohort model of training meant that I went into teaching with a strong corps of friends and colleagues that I could call on for support and collaboration, which is one of the great benefits of the residency model. Even if you didn’t go through such a program and feel like you don’t have allies, find them. In your school, in other schools, or on the web.

5. A supportive administration and staff change everything. My colleagues at my school have been amazing — offering ideas, support, solid backup on discipline, and even offering to help grade. Compared to the horror stories I have heard from some other schools, I count myself very lucky in this regard. Teachers don’t often have much of a choice in the character of their colleagues and supervisors, but if it is at all possible, trade whatever you can for good people on your side.

That’s the top five reflections so far. I definitely don’t have it all figured out yet — in fact, one thing I enjoy about this profession is that the opportunities to improve seem endless. But it’s getting better. Especially now that I’ve had a few days to rest, I am looking forward to seeing how the rest of the year plays out.

Use Your Phone as a Streaming Document Camera

As a science teacher in an increasingly technology-driven world, I have found document cameras to be very useful for a number of purposes. A connection to the SMART Board or projector allows students an enhanced or alternative view of any class demonstrations, and I can also ask students to explain their written or solved work for the class with everyone following along on the screen.

Document cameras ain’t cheap though. The official SMART Document Camera runs about $800 (!), and even a generic webcam can run $40-50 or more depending on what you are looking for. For the budget-conscious (or budget-constrained) educator, these options can be beyond reach.

I was looking for a cheaper alternative and thought, wait a minute. I’ve got a camera right here on my Android phone already. Why not find a way to use that?

Here are the results from trying out two different apps.

Phone Stats

I have a smartphone, but its a pretty generic one. Go back to that bit about budget-constrained. Right.

LG Optimus V (Virgin Mobile), with Android 2.2 and a 3.2 MP camera.

IP Webcam

The Android app IP Webcam allows you to turn your phone into a little video stream server. You can adjust various settings (video resolution and quality, orientation, etc) and then stream to a local IP address. The stream URL can then be viewed via a media client like VLC or Quicktime, or directly through your browser’s native video player.

You can also have it fade the screen to blank to save battery (it doesn’t let you actually shut off the screen, since that seems to be linked to ramping down the processor as well).

The partial screen capture (scaled to 60%) below shows the feed in Firefox with the phone held about a foot away from the document under a normal table lamp in otherwise dim lighting conditions.


Here is another screen shot, also holding the phone about a foot away, that shows resolution of handwritten text and diagrams for demonstrating problems.


Five minutes of WiFi broadcast at 640×480 (3MP), full quality, and phone screen on fade-mode resulted in a battery drain of only 2%, which is pretty good. If the display were left on, I’m sure this would be much higher. I also have a very weak processor and no autofocus, both of which would take more power if your phone has them. However, I see no reason why you couldn’t just plug in your phone while streaming if you needed it.

As you can see from the browser control interface below, the app supports many ways to access the stream (including Skype integration), and also allows screen-capture photos and audio streaming as well (I did not test the bitrate).


I was not able to get the stream to work over 3G, since the IP address that the cell tower assigns to my phone seems to be LAN only. It would be an interesting experiment to see if another Virgin Mobile customer standing next to me (and hence presumably connected to the same tower) would be able to see my stream on his/her phone!


The DroidCam app works through either WiFi or USB, and hence requires a client install on the viewing laptop. The pro version claims to also add 3G and bluetooth connectivity, as well as remote control for flash, zoom, autofocus, etc.

The app performs poorly compared to IP Webcam. The video quality is noticeably lower for the same resolution, and the phone experiences a higher battery load (3.5% in five minutes, same conditions). Also, the option to display the stream through the browser via an http connection is disabled unless you buy the pro version, so you must use their client software to view the stream.

The advantage over IP Webcam presumably is that you can use USB mode to stream directly to a client computer even when you don’t have WiFi available. However, I was not able to get the USB mode to work properly on my Windows 7 netbook with minor fiddling. I would assume that if one could get the USB mode working, battery drain would be significantly less, since the phone should be able to draw on the USB power bus while connected.


Of the two apps tried above, I would go with IP Webcam for sure. I tried the app on WiFi mode while connected to the BPS network and it worked fine (the app uses the standard http web port 8080, which means that its highly unlikely anyone will block the port). There seems to be no need to try very hard to get the USB on DroidCam to work, especially considering that the quality is lower.

At only 3MP, fine detail is going to be lost, but for visual enhancement it seems like this should work fine! Also, if you have a higher resolution phone camera than me, obviously your phone will deliver a higher resolution image.

Bonus: the web streaming means that any student with the right IP address (which you can give them) on the local net can actually get the stream directly on their smartphones or laptops anywhere in the school. I don’t think even the $800 SMART Document Camera will do that, and this app is FREE!

My Classroom!

IMG_20130722_134947The up side of freedom is that I can do whatever I want! The downside of freedom is that now I need to decide what it is that I want. Damn.

I got access to my classroom a couple of weeks ago, and I’ve been nerding out on how to set it up. It’s a squarish room with pair tables for 22 students, fixed lab counters and sinks around the outside perimeter and a pair of fixed demo tables at the front. I’ve got old school vertical sliding whiteboards and a small SMART Board off to the side.

I have no idea what to do with the roughly 2 million little drawers and cubbies of the built-in cabinetry in the back room.

Right now, I’ve got it set up in three groups of 6 and one group of 4. I toyed with other arrangements as well. Lecture-style rows had the advantage of order and sight-lines to the board, but I thought it would make things more difficult for group work, collaboration, and discussion. I also tried a round-robin circle of tables to emphasize the importance of discussion in the science class, but I thought that it might be too good for this purpose — meaning that students would be tempted to distract each other across the room. Plus, group work remains hard in that arrangement anyway.

IIMG_20130722_145545 plan to use the vertical sliding whiteboard for objectives and essential questions for the unit / lesson / day, and have it in the “up” position. The board underneath will be for classwork and examples we do in the lesson. The side board near the door will have the agenda for the week and all due items.

Corkboard… I’m thinking exemplary student work, class rules/expectations, and some of the many NASA posters I just got loaded up on thanks to former colleague Kevin back at Dryden.  In the back there is a small table that I will probably use for a little career station, with info on science and engineering as careers, current events in science, and profiles of diverse scientists who are doing awesome work.

As for posters,  in addition to the aforementioned NASA swag, I ordered four more: a “No Whining” sign, “Believe in Yourself: You’re More Capable Than You Think”, “Life Begins at the End of Your Comfort Zone”, and “Think: It’s Not Illegal Yet”. I plan on making a few more for classroom procedures and expectations, as well as (if I have time) a few of my favorite quotes with pictures of the person who said each.

“You must understand the whole of life, not just one little part of it. That is why you must read, that is why you must look at the skies, that is why you must sing and dance, and write poems and suffer and understand, for all that is life.”  – Jiddu Krishnamurti (philosopher)

“For me, I am driven by two main philosophies: know more about the world than I knew yesterday — and lessen the suffering of others. You’d be surprised how far that gets you.” — Niel deGrasse Tyson (astrophysicist)

“Never be limited by other people’s limited imaginations…If you adopt their attitudes, then the possibility won’t exist because you’ll have already shut it out … You can hear other people’s wisdom, but you’ve got to re-evaluate the world for yourself.” — Mae Jemison (astronaut)

That’s all for now… I’m sure once I start getting down to the actual setup process much of this will change!

Waves Project: Earthquakes and Tsunamis

[Note: Scroll down to the Files section for downloadable lesson/project materials.]


I’ve been reading and learning a lot this year about the benefits of incorporating authentic tasks, project based learning, data, analysis, synthesis, and scientific discourse into the classroom. As we approach the end of the year, I’ve finally felt confident enough to try putting together my own project to fit with the principles I want to apply in my physics classroom.

Today is Day 1… I’ll post again with a reflection on how the whole thing goes.

This project is taking place about halfway through our unit on Waves — after mechanical waves but before electromagnetic waves. My hope is that students would be able to apply what they have learned to an authentic task that mimicked how science is really used to study the world and try to help people.

I want to emphasize that I am still near the end of my BTR residency year and M.Ed. program while designing this project. This is the first time that I attempted designing a project of this scale, and also the first time teaching it. I would definitely appreciate any feedback or suggestions for further refinement.

Project Overview

The project is based on the 2004 Sumatra Earthquake and Tsunami that devastated much of South East Asia. Students are given an introduction to earthquakes and tsunamis, provided with a project overview handout, and shown some video clips and photos.

Students are told that a massive earthquake and tsunami scenario has just occurred in the Indian Ocean, and that their lab groups are an investigative team that will be responsible for constructing a “What Happened” story using scientific analysis. Each team is assigned a particular city of interest: Banda Aceh (Indonesia), Chennai (India), Dar es Salaam (Tanzania), Mogadishu (Somalia), Padang (Indonesia), or Trincomalee (Sri Lanka).

The first part of the Work Packet involves background reading in the textbook 1, interpretation questions, and group discussion. The teams then receive two “technical memos”: one from the USGS National Earthquake Information Center, and one from the NOAA Tsunami Program. The data, properly interpreted, allow students to calculate the basic features of the earthquake p-waves and s-waves as well as some properties of the tsunami wave (such as arrival time at various cities, difference in speed and amplitude between open ocean and shore, etc). The third component of the project is an interpretation and discussion segment, followed by a final poster to present the final conclusions.


This section describes my thought process and sources while putting together the project.

Lesson plans for every day of the project include silent individual work and think time. This is an access issue — many students prefer and may even require individual reflection and a chance to organize their thoughts before being ready to participate in group work.

I also have planned time into each day to allow for class-wide or group discussion designed to share information between groups, make sense of new vocabulary or concepts as a class, and engage in dialogue. Video clips, photographs, and eyewitness accounts from the real 2004 Sumatra disaster are also used to engage and interest students, as well as to maintain connections to the big ideas about how science is used in the real world.

Alignment With Standards

As per UbD philosophy, I started with the standards for which I wanted students to show evidence of applied knowledge. Based on where we were in the unit, I selected the following Massachusetts Physics Framework standards for focus:

  • 4.1 Describe the measurable properties of waves (velocity, frequency, wavelength, amplitude, period) and explain the relationships among them. Recognize examples of simple harmonic motion.
  • 4.3 Distinguish between the two types of mechanical waves, transverse and longitudinal.
  • 4.5 Recognize that mechanical waves generally move faster through a solid than through a liquid and faster through a liquid than through a gas.

And though they are not yet binding on BPS, I figured while I was at it to take a look at the relevant Next Generation Science Standards as well. I did not consider NGSS when designing the project; these suggested alignments are made in retrospect.

NGSS Dimension 1 – Practices2:

  • Practice 1 – Asking Questions
  • Practice 4 – Analyzing and Interpreting Models
  • Practice 6 – Constructing Explanations

NGSS Dimension 3 – Core Ideas3:

  • HS-PS4-1. Use mathematical representations to support a claim regarding relationships among the frequency, wavelength, and speed of waves traveling in various media.

 Technical Aspects

Nearly all scientific and technical information that I used concerning the physics of earthquakes/tsunamis, including how they are studied and measured, was found at the USGS Earthquake Hazards Program and the NOAA Tsunami webpages. Specifics for the 2004 Sumatra earthquake and tsunami, which formed the baseline data set I started from, were either directly on, or linked from, the USGS 2004 Sumatra quake page and the NOAA Center for Tsunami Research.

Earthquake p-wave travel times were estimated based on data from the USGS National Earthquake Information Center. S-wave arrival times were estimated using a base speed of 4.5 km/s, and then adjusted lower based on the distance from the epicenter to the arrival point. This accounts for the fact that both P and S waves move faster through the deeper layers of the earth.

My initial thought was to have students interpret a real seismogram trace from the USGS archives. However, I had to balance the complexity of teaching/learning all the features of a real trace with the objectives of the project. Since the point of the project was to learn about and apply knowledge of waves (not earth science per se), I decided to sacrifice some realism of the seismology aspect and focus on wave physics.

I made my own simplified seismogram trace in Matlab using a base sine function for each of the p-waves and s-waves. Wave parameters (amplitude, frequency) were taken from representative values for the Sumatra quake. Both waveforms were then perturbed with an additional, superposed sine wave with a randomized small amplitude, in order to give the waveform the look of “real” noisy data. I know it doesn’t quote look like a real seismogram trace would (especially the duration), but again, my focus for now was to see how they handle interpreting the wave information.

Tsunami arrival times were estimated from a simulated reconstruction of the wavefront propagation done by Japan’s AIST.

Surface distances from the epicenter (3.316°N, 95.854°E) to the selected cities of interest were calculated using the Latitude/Longitude Distance Converter from the National Weather Service.

Tsunami heights reaching the shores of the selected cities were eyeballed from a mix of published simulation results and from Googling eyewitness accounts and field reports.


I would love to hear back from anyone who uses these! Feedback, comments, and areas for improvement would be greatly appreciated.

(Note: Only the most recent versions of each file are shown. The changelog is below, and see the comments thread for the thought process. I would be happy to share old versions by request, though bear in mind that there is usually a good reason I would take the time to update them.)

If you make use of these materials, please consider leaving a comment or contacting me with your thoughts. 


v130522 – original project files

v130606 – revisions made after trying it on three blocks of junior-level high school physics:

  • Data: Earthquake waveform made more realistic. (Though this is still greatly simplified.)
  • Data: p/s-waves lumped together into body waves, then surface waves added.
  • Data: body wave arrival times distributed around assumption of  7.1 km/s
  • Data: surface wave arrival times distributed around assumption of 3.8 km/s (down from about 5 km/s)
  • Data: separation of non-related sentences (reduce confusion).
  • Work Packet: adjusted to ask for body waves and surface waves instead.
  • Work Packet: rephrasing to be more specific about what is being asked.
  • Rubric: tightened the difference between Partial and Acceptable (was very wide before)
  • Rubric: added point values
  • Rubric: more specific phrasings
  • Rubric: moved 5% of weight from poster to teamwork/participation
  • Added Matlab waveform generator .m script and .fig file. (You should be able to run this in Octave too if you change the % comment markers to #. The plot commands probably won’t work.)


Many of the resources available at Tools for Ambitious Science Teaching (particularly the Discourse Tools) were enormously helpful in the planning process for this project. Additionally, the GRASPS method of planning a rich learning task (part of the Understanding By Design framework) was used to lay out and organize the initial ideas, as part of the full UbD plan for the unit.

Also many thanks are due to my BTR co-resident Akil Srinivasan, my residency collaborating teacher Sotiris Pentidis (Boston Community Leadership Academy), and my clinical teacher educator Andrea Wells (Boston Teacher Residency).


Show 3 footnotes

  1. We are using CPO Science’s Physics: A First Course this year.
  2. I haven’t really sat down and scoured these for intended implementation. My claim of alignment is based on the summary descriptions in the Framework.
  3. As much as I love many aspects of the NGSS, I am disappointed that the Core Ideas dimension contains wave physics almost solely in a technology/application context. This is the only “pure” wave standard I found.

Lesson Plan: Intro to Parallel Circuits

I’ve been wanting to upload more lesson plans and materials that I think worked well — like everything else, its just a matter of finding the time.


The attached are a lesson plan and a handout for how I did the introduction to parallel circuits. At this point in the unit, we had already covered the conceptual understanding of what voltage, current, and resistance area. We had already covered Ohm’s Law as well, both activity-based and mathematically.

I have removed the following from the lesson plan:

  • Mention of or planning for individual students. Normally, in addition to planning for all students in general, I am preparing for particular students who tend to need additional prodding to focus, often have clarification questions, or perhaps need additional language assistance. 
  • The section on planning for individual students with learning disabilities, since the plans would necessarily detail confidential information about my students.


My students had not done series circuits yet. The decision to start with parallel came after some thought — I wondered if there are good reasons why series circuits a usually taught first. I really couldn’t think of any that didn’t also have an analog on the parallel side. For example, in a series circuit, it is usually intuitive why the current is the same through all components (there is only one path for the charges to take).

However, understanding why the voltage drops in a series circuit have to add up to the total battery voltage (proportional to their resistances) requires more thought (and a good understanding of what voltage physically is). On the other hand, in a parallel circuit, the idea that the current in each branch should sum to the total entering and leaving the battery is easy to visually demonstrate. But why should the voltage across all components never change, no matter how many you add or remove (within reason)?

I figured it was six one way, half a dozen the other and went with parallel first for the novelty.


These are free to use, modify, and distribute. Please credit me and/or this blog if you use it for something, and I’d love to hear any revision suggestions for next year or reports on how it went with other students! 

Lesson3.1A-ParallelCircuits [pdf]

Lesson3.1A-Handout [pdf]


Students in general pieced the important concepts together well. One thing that surprised me was that one group seemed to be able to use the data they were getting in the lesson to validate an incorrect model of parallel circuits: that it was always the closest resistor to the battery that got the most current. I realized 1) that this was not a student idea that I had anticipated, and 2) that the setup of the lab allowed this alternative conception to be reinforced (note that the resistor with lower resistance is, in fact, closer to the battery on the circuit diagram).

I asked that group to test out their idea by swapping the resistor positions, telling them to predict what would happen first. They conferred and said that “it was probably about fifty-fifty” on whether or not their theory would be disproven by the new data. They were able to discover that the current depends only on the relative value of the resistances.

I then reframed the post-activity discussion to center on this student reasoning/discovery instead of my originally planned questions. In a way, this was serendipitous — I got students to demonstrate for their peers what real science looks like. We have an initial model that attempts to explain something we observe, we ask ourselves what we need to do to validate that model, we attempt validation, and then revise our model. That meta lesson was possibly more important in the long run than the actual content of parallel circuits.

The next day, we followed up with discussion, reading, and applying mathematical relations to what we learned in the exploratory activity.

Teacher Tweets

After a few months of mild annoyance at not being able to access Twitter in schools, I began to search for the reason that BPS blocks it. Ironically, searching for “twitter” on the the BPS website yields only an exhortation at the bottom of a welcome page to follow BPS on Twitter. Googling for it didn’t help either.

I think blocking Twitter in schools is silly. Firstly, students (and teachers) are simply going to access it on their phones anyway. (And if you think cell phone bans work… well, we try.) More importantly, there are a lot of great reasons to be using Twitter in the classroom. I’ll list my top three here:

  • Posting additional enrichment content. I created a separate twitter account for my teaching which I use to post additional content that we couldn’t get to in class, such as videos, articles, podcasts, and more. Sure, I post these on a class page, but that is not enough… if you think students are visiting your class page for anything except checking grades, I’m skeptical. The reason is that the contemporary app-flooded internet has made all information “me-centered”; there is so much information that comes to you (via social media feeds and apps that push content directly to phones) that there is no time or reason for many people to actually actively seek out information. So I think we should play the game; make some of that pushed content our content too. Which brings me to…
  • Communicating with students. Building positive relationships with students means communicating with them in the way they prefer, which is not email or even blogs anymore. It’s through their mobile devices, which every single one of them has. Twitter provides a way to directly reach students, broadly or individually, WITHOUT having to know their phone numbers or giving out yours. (This has been very useful for coordinating The Free Knowledge Stand.) This communication is real time and can include links to information and content around the web. Moreover, Twitter is not just “their” preferred medium of communication.. the new wave of incoming teachers grew up with social media too.
  • Connecting with real world information. With all the teacher buzz I hear about “bringing in real world examples” and “relating science to the lives of our students” it really does seem asinine to have our fingers in our ears about social media in the classroom. Check out my Twitter lists for Science and NASA, for example. You can set up similar lists on any topic or search tag you choose. Which means that Twitter will hand you a real-time, instant, and broad survey of the individuals and institutions discussing ANY TOPIC YOU WANT right now… and its good odds that the best sources among these will be linking to all sorts of information and resources too. Why not include yourself in this discourse? Why not include students in it?

Certainly there are good reasons to block certain information in schools. However, I think Twitter is less likely to be used distractedly (so long as cell phone use remains regulated) for a number of reasons. for example, Twitter is less “social” (in the personal sense) than Facebook, because there are no extensive profiles, albums of photos, lists of interests, time-killing apps, etc. Put another way as I wrote in an earlier post, Twitter is about ideas, not people. And while one certainly can use Twitter for personal communication, there is little difference between doing so and a group text — which is usually more immediate.

Beyond content filtering, there are other challenges. For example, I can see why districts would be uneasy about opening a channel that would allow interaction between teachers and students outside of the clear(er) legal lines of the physical classroom. But the world is changing way too fast to hang onto that fear… the solution could be as simple as a central set of guidelines for use to which teachers agree and a liability waiver.

This year, a Twitter account for my classroom is an experiment. I introduced it late in the year, without a clear plan for what would be on there. As a result, I am not surprised that the engagement is limited to just a few students. However, next year, I plan to incorporate it right from the start with a clear outline of what kinds of information will be posted and why.

I plan to blog the results this fall.

The Free Knowledge Stand: Physics at Breakfast

100_0787This January, upon return from the winter break, students were greeted with the grand opening of the Free Knowledge Stand at breakfast in the cafeteria.

My co-resident and I keep office hours after school on Tuesdays and Thursdays, which are usually well-attended. However, we noticed that many of our students who needed the most support in Physics were not showing up for additional help. At first we assumed that they maybe just didn’t want to, had other priorities, or didn’t value the subject matter or our time. But when we asked students why they weren’t showing up for extra help, we got a variety of reasons that at first we hadn’t considered: transit, work, and family.

Due to Boston’s complex busing system, many of our students are coming from very far across the city, and need to catch BPS shuttle buses to major transit stations, or risk having to make a 2 hour trek home via surface buses (which, as we know, isn’t exactly providing equitable access to underserved populations). These shuttles leave immediately after school, and there is no recourse for missing them other than making one’s own way. Additionally, we found through our case study interviews that many of our students either work after school to help support their families or have to take care of siblings while others work.

Ok, easy we thought. We’ll just come in early before school and have students come in when they get to school. However, this wasn’t as straightforward as it seemed. One hurdle we ran into was (necessary) security: students aren’t allowed to roam the halls unescorted before hours. So we would be constantly running back and forth between classroom and cafeteria.

The other hurdle was breakfast. The students were reluctant to leave the cafeteria in the morning because that is when they eat breakfast — and food is not allowed in the classrooms. If you’re getting into school at 7am after a 1.5 hour commute to school, having breakfast before is probably not an option; and if you’re on the Federal Free or Reduced program for low-income students (85% of our student body), you probably don’t have many other options for breakfast anyway. So that wasn’t budging.

The solution: The Free Knowledge Stand, a play on a commonly shouted phrase of our mentor teacher in the hallways, “Free knowledge! Free knowledge today! Come and get the knowledge! Free knowledge my friend, why are you not learning? Free Knowledge! …”

So, every morning, I send out a tweet from my teacher Twitter account letting students know when we will be there. My co-resident and I try to get in at 7am (doesn’t always happen… curse you snooze alarm), when we set up our laptops and our Free Knowledge Stand sign in the cafeteria. Most days, we’ll get a few clients. Some days, no one comes for help — on those days we just do our work of planning and BTR papers as we normally would.

And aside from the content help, the Free Knowledge has been a great way to form positive relationships with students. Many of them like to stop by with their breakfasts and just say hi, talk about what we did in class, and ask far-out questions about the material that they were wondering (“So Mister, is there like, friction everywhere? Like what about in the sun, is it you know like, too hot for friction in there?”).

Since there are two of us, we are often able to tag team, one resident directly helping students while the other does lesson planning and chiming in when able — sharing the workload. The Free Knowledge Stand has been a great way to provide extra physics help and get to know students, without really taking any additional time out of our days. And yes, it is always the grand opening — we’ve got cheesy/nerdy science teacher reputations to maintain after all.

Lesson Plan: Predictions With Conservation of Energy

by Nalin A. Ratnayake

Unit: Work and Energy, Component 2: Conservation of Energy
Date: January 15th, 2013
Day/Block: Day 4, Blocks A(3) / E(2) / F(6)
Time Available: E 58 min, A 58 min, F 65 min

Objective: You will be able to predict and analyze motion using the Law of Conservation of Energy.

Criteria for Success:

  1. Can I predict the final mechanical energy of an object in motion using energy conservation?
  2. Can I determine if and how an object’s mechanical energy has changed?
  3. Can I solve a physics problem using energy conservation?

Assessment: Handout and Exit Ticket
The handout will show qualitative understanding of Criteria for Success 1 and 2.
The short worksheet will show quantitative understanding of the Criterion for Success 3.

[10 min] Do Now

Please have a seat and work quietly on the Do Now.

A ball of mass 15.5 kg is released from rest at a point 1.2 m high.

1. If we ignore air resistance, what will be the velocity of the ball at the lowest point of motion?

2. If we assume that air resistance does -20 J of work on the ball as it falls, what will be the velocity at the lowest point of motion?

Share out. Specific questions to ask students: Can you step me through how you found the velocity? How do you know much initial mechanical energy the ball has? How do you know that the total mechanical energy will remain constant? Where does the kinetic energy of the ball come from?  What does the work done by friction do to the mechanical energy of the ball?

[2 min] Framing the Day

The scenario we will be looking at today will be very similar to the Do Now… only more dangerous!

Objective: You will be able to predict and analyze motion using the Law of Conservation of Energy.

Criteria for Success:

  1. Can I predict what will happen to the mechanical energy of an object by using energy conservation?
  2. Can I determine if and how an object’s mechanical energy has changed?
  3. Can I solve a physics problem about the motion of an object using energy conservation?

Can someone please raise his or her hand and explain what we are doing today?
Can someone please raise his or her hand and remind us how we will know if we are successful today?

[35 min] Will Professor Lewin Survive?

Note: The following activity will be outlined on a handout / graphic organizer.

We are handing out a worksheet. These will be collected today at the end of the period. Please take a couple of minutes to read the first two sections, labeled “Video” and “Directions”.

Professor Walter Lewin is going to put his life on the line to prove the law of the conservation of energy. He will release a 15.5 kg pendulum bob from his chin, and wait to see what happens when the ball swings back at his face! Will the ball smash his face in? Or will the laws of physics protect him? We will find out….
Can someone please raise their hand to volunteer to read the first paragraph for us?


  • We will be watching a video that goes along with this handout. Do not move ahead. Some questions we will do as a class, some as a table, and others individually.
  • Write your answers in complete sentences wherever possible. This helps organize your thinking and gives you better study materials later for quizzes and tests.

Can someone please raise their hand and tell us, what is one direction we should follow today? Why should we do that?
Can someone please raise their hand and tell us, what is another direction we should follow today? Why should we do that?

Play the video of Walter Lewin putting his life on the line to prove Conservation of Energy.

Stop the video at 2:54.  (Right after “…this will be my last lecture.”)


Answer question 1 individually on your worksheet now.
1. What kind(s) of mechanical energy does the ball have right now and how do you know?
Quick share, check for agreement or disagreement and why.

Take a couple of minutes to work with your table group on the first column of the table (question 2).
After each column, ask a student to share out what their group answered. Questions to ask: Why do you think that the mechanical energy will increase/decrease? Why will this make the height higher/lower? What does positive/negative work do to the mechanical energy of the pendulum? How will we know if the mechanical energy is higher/lower?

Repeat for questions 3 and 4.

2. Prof. Lewin does not push the ball and we assume no air resistance 3. Prof. Lewin does not push the ball but we include air resistance 4. Prof. Lewin accidentally pushes the ball as he lets go
What kind of work will be done on the ball (positive / negative / none)?
What will happen to the total mechanical energy of the ball (increase / decrease / constant)?
What will be the height of the ball when it swings back to Prof. Lewin (higher / lower / same)?
Will Professor Lewin be safe (yes / no)?

Add this diagram to the slide to be clear about what I mean by “height”:

Answer question 5 on your worksheet individually.
5. Make your prediction: What will happen to the mechanical energy of the ball? How will you know if your prediction is right or wrong?

Play the rest of the video.

Show a side by side of the before (at the time of release) and after (1 cycle):

Ask the class:
I was careful to stop the video exactly when the ball reached its maximum height on the return swing. Is he at the same position or not? What do you notice about the ball’s position?

At this point there should be at least 20 min remaining in the period.

Answer the following question individually:
6. What happened to the mechanical energy of the ball, and how do you know?  What evidence tells you so?

Possible questions:What happened to the mechanical energy of the ball, and what evidence do you have? Was there work done on the ball? If so, by what force and was it positive or negative work? How can we explain what happened using the Law of Conservation of Energy? As students answer, ask for agreement or disagreement and why.

In a couple of minutes, I’m going to ask you to answer question 7 individually. But before we do that. you have 2 minutes to check with your partner and make sure you agree on what happened. This is your only chance to confer before answering question 7 on your own.

Now, answer question 7  on your own.
7. Write out a short story of what happened to Prof. Lewin’s swinging pendulum. You must answer the following questions in your story: Was work done on the ball and by what force?  What did this work do to the mechanical energy of the ball? What did we observe that told us what happened to the mechanical energy of the ball?

[5 min] Exit Ticket

Professor Lewin released a 15.5 kg pendulum from 1.20 m high. We carefully measure the height of the ball when it swings back towards him, and determine that the ball only went 1.05 m high when it came back. How much work was done by air resistance on the ball?

Collect student work. If running out of time, ask co resident to help photograph worksheets and exit tickets of case study students as a worst case fallback option.

52 min total:  ~5 min of buffer
If need be, the CONFER section of the plan can be eliminated without impact to the cognitive demand or student sense-making in the lesson.

Lesson Plan: Conservation of Energy using a Music Video

Lesson 2.2: Exploring Conservation of Energy

Unit: Work and Energy, Component 2 – Conservation of Energy
Date: January 10th, 2013
Day/Block: Day 1 –  A/E/F
Time Available: A 58min / E 48min / F 65min

You will be able to design and analyze a Rube Goldberg Machine using the Law of Conservation of Energy.

Criteria for Success:
Can I design my own machine that transfers mechanical energy between objects through work?

Can I use the Law of Conservation of Energy to explain how my design transfers energy?

Handout with machine design and analysis questions.


[10 min] DoNow:

The complicated chain of events in the music video is called a “Rube Goldberg Machine”. These machines use many transfers of energy between a whole lot of objects in order to do a very simple task.

Invent your own small (2 objects) Rube Goldberg machine. How would you use one object to make another object do something else? Where is there work and energy? How does one object transfer energy to another?


[10 min] Discussion: Music Video

Show OK Go’s music video for “This Too Shall Pass”: (4 min)

Note: Watching the video was assigned as homework the previous night, along with the following guided questions: Where do you see work? Where do you see energy being transferred from one form to another? Write down at least 1 example (note the video time), and make sure to explain what object is doing work on what other object, what kind of energy is being transferred, and how you know.

Talk to a partner next to you and share 1 example of work and energy being transferred from one object to another. I will ask several students to share an observation that their partner noticed, and explain to me what object is having work done on it and what kinds of energy are involved.

Possible questions to ask:
What did you see? Be specific, tell me what happened to the object that makes you think there was work done. What kinds of energy do you think that the object has?  How do you know that the object has that kind of energy?

Record student observations on the whiteboard.

[15 min] In-Depth Analysis: Tire

Show video clip of the tire section twice (7 second clip starting at 1:03). Ask students to write down exactly what they see happening to the tire. Have students share their observations, and assemble a record of the tire’s journey on the board to refer to later.  (Make sure that the bucket hitting the tire is included.)  Hand out the worksheet for scaffolded analysis of the tire scenario.

Refer to your handout. Take 30 seconds to answer the first question by yourself. Ask one student to share what they wrote with the class.
1. At the beginning of the scenario, does the tire already have mechanical energy? If so, what form(s) is it in, and how do you know?

Take two minutes to answer questions 2 and 3 with a partner.  Ask one or two pairs to share, depending on time.
2. During the scenario, is work done on the tire by any other object?  Is this work positive or negative, and how do you know?
3. What happens to the tire’s total mechanical energy when the work is done to it?

Take four minutes to answer questions 4 and 5 with a partner. Ask one or two pairs to share, depending on time.
4. Describe what happens to the tire’s GPE, KE, and total ME as it goes through the scenario.
5.  What happens to the tire’s mechanical energy at the end of the scenario?

[15 min] Creative Activity: Design and Analyze

Turn over your handout. Now you have a chance to design your own Rube Goldberg machine! Draw your machine in the space provided, and use the Tire Analysis as a guide to answer the analysis questions below. The questions are due tomorrow for stamps. If you don’t finish in class, please complete the analysis questions as homework.

6. Draw your own piece of this Rube Goldberg Machine that uses 1 object. You must include at least 1 transfer of energy from one object to another.

7. What is your main object in this scenario? :

8. Describe what happens to your object’s GPE, KE, and total ME as it goes through the scenario beginning to end..

9. Where is work done on your object or by your object? How does this work change your object’s total mechanical energy?

10. Explain how your machine obeys the Law of Conservation of Energy, MEi + W = MEf.

Momentum Supplies… Check

While planning for our unit on momentum (hopefully starting Tuesday), it suddenly occurred to me that I don’t need to use YouTube videos… there’s a toy shop just down the street! Behold my first direct purchases for my classroom as an educator:

Marbles in three different masses and a Newton’s Cradle! Weeeeee for conservation laws. Playing >> Watching any day. Will post the lesson plan when I have something presentable…