March 2011 - Physics In Flux

iPod Speakers to Bridge E&M and Waves #physicsed

Posted on March 25, 2011 by admin — 3 Comments ↓

We concluded our iPod Speaker Project today, an annual competition in which Regents (Honors/General) Physics students build speakers for their iPods, cell phones, and MP3 players using a neodymium magnet, 30-gauge magnet wire, and whatever pieces and parts they can scrounge together.

The week begins with a brief introduction to waves and sound following the end of our E&M unit. We talk about energy conversions, from stored chemical potential energy in the iPod batteries all the way to electrical impulses in the brain. We also talk very briefly about basic speaker and microphone functionality. At that point, I kick the kids loose to do some research, gather their materials, and start work on a reference design.

Within about 45 minutes of class time, most groups have a working speaker. NOW comes the real work — taking their reference design, evaluating its strengths and weaknesses, and making appropriate design changes and documenting their effects. Students analyze their speaker performance for loudness, clarity, and frequency response, and then modify in an attempt to optimize. Once they’ve gone through a couple iterations, they team up to put together a design report, comparing and contrasting their different designs and attempting to explain why they observed their different responses.

It’s a very open and interesting week, with many groups developing different theories. This becomes the opening discussion for our technical discussion of sound and waves the next week, beginning with misconceptions and working through to basic wave characteristics and phenomena such as reflection and interference. It’s typically a fun week as students start in fear and awe, and work through the “I can’t do it” stage until they finally build confidence and understanding.

Almost as exciting is the final project evaluations. Students evaluate the projects and reports of their peers basic on a pre-determined and publicized scoring rubric. The grading process is always intriguing to watch, as students love to ask questions which I refuse to answer, forcing them to critically evaluate what is being asked, and how the supplied project does or does not meet the criteria. Finally, students are asked to write a single paragraph explaining in their own words how a speaker works, or, alternately, tracing the energy conversions from iPod to brain. This helps me prepare for the following week’s lecture opening, while simultaneously assessing and reinforcing connections made during the week!

Snap Circuits for E&M Labs #edtech #physicsed

Posted on March 13, 2011 by admin — 9 Comments ↓

One of my frustrations in teaching introductory electricity and magnetism to high school students involves discrete component labs. Ohm’s Law is fairly straightforward – a voltage source, a couple wires, and a voltmeter and ammeter will do the job nicely. Series circuits take a bit more time, adding a few more resistors and connecting wires, and now the students have to move their voltmeter around. By the time we get to parallel circuits, however, students have trouble translating the circuit diagram on the page to the mess of wires they see in their lab stations. Then, throw in a moving voltmeter and ammeter, and the educational value starts to decline as the frustration level rises.

One potential solution is the use of breadboards to better organize student circuits. I’ve had some success moving from stray wires to breadboards, but especially in the more general-level physics courses, I spend more time trying to explain the connections in the breadboard and why it works, and students never make the connection to their circuit schematics because they can’t see inside the breadboard.

Recently, with the assistance of the IEEE Electron Device Society and RIT’s Microelectronic Outreach Program, I was able to play with an Elenco Snap Circuit SC-750 Student Training Program kit for two weeks. These kits feature a variety of discrete components placed into snap-on components which make it easy to visualize and observe circuit schematics on the actual circuits being built. The kit includes resistors, transistors, Ics, switches, motors, capacitors, relays, transformers, 7-segment display, diodes, etc.

At first glance, I was impressed with the kit case and foam inserts for storing parts – not only does this keep the kit neat and organized, in a lab situation where I have 120 students playing with the kits throughout the day, it makes it very easy to verify that all components have been put away and stored properly, almost “resetting” the kit for the next group. The kit also comes with five project books, a teacher guide, and three student guides.

The project books themselves are straightforward, showing the final completed circuit put together on a snap-in structural foundation. For educational purposes, though, I would have liked to have seen an actual circuit schematic, and perhaps a few words explaining why each circuit works as it does. It’s great as an electronics toy, but building and documenting laboratory learning experiences would be a fun project for a single or small group of educators.

Components-wise, there were many more components in the kit than I would require, even for my AP-C Physics classes. The integrated circuits, though fun for projects, are not described in detail, and function almost like a magic “black box” in the kits. An analog meter is included, but scale ranges and functions are not described. From a resistor standpoint, the kit has a few resistors of fairly wide-ranges, whereas basic series and parallel circuit labs would probably benefit from 3-4 resistors in each order of magnitude to allow students to easily verify Kirchhoff’s Current Law and Kirchhoff’s Voltage Law for whatever configuration they are placed in. The solar cells are a nice touch, but the equipment for turning a PC into an oscilloscope is a bit much for our high school physics classes, although perhaps beneficial to other groups.

Another terrific improvement opportunity would be the inclusion of a wound hollow solenoid. Throw in a neodymium magnet and the kit could be easily extended for a variety of electromagnetic induction experiments. Throw in two solenoids (concentric?) and some iron cores and you can also explore transformers in a bit more detail. The meter included is a bit lacking, so inclusion of a cheap multimeter and a few more snap-in flexible wires would be of tremendous benefit. Finally, although the kit does include an “open” component in which you can snap in discrete components, having a few more of those could prove useful for extending projects.

In short, I see the Elenco Snap Circuits as a terrific start toward an “E&M Lab in a Kit” offering. The kits are designed and marketed as electronic toys, and function very well in that capacity. My students had a great time playing with the kit and building various projects, but all stated that the educational value could be greatly enhanced with true schematics and descriptions of the “What” and “Why” of the projects.

Our demonstration / trial is being continued in other classrooms at a variety of grade levels, and will be fed back to Elenco as an opportunity to expand their market from electronic toys into educational tools. I would like to thank the IEEE, RIT Microelectronic Outreach, and Elenco Electronics Inc. for the opportunity to be a part of this program.

Blogging: Enhancing Instruction #edtech

Posted on March 12, 2011 by admin — No Comments ↓

As part of our district’s recent technology symposium, I was asked to present a short seminar on “Blogging: Enhancing Instruction.” Last year I was asked to present on a similar topic, focusing on how blogs could be used in the classroom. The seminar was a success, but I quickly found that participant goals ranged from learning what a blog was to exploring new ways to utilize blogging in the classroom to technical concerns with setting up a blog.

Taking what I learned from last year, this year’s seminar was designed as a largely-independent guided exploration into the aspects of blogging of greatest personal interest. Taking a page from my Twitter-network brethren, I set up a Box.Net site which broke up the seminar into four main areas:

Student Blogs
Educator Blogs
Blogging Platforms
Blog Implementation

Allowing participants to work through areas of greatest interest not only provided each participant with an opportunity to focus on their individual goals, but also allowed me to better wander around the room assisting and discussing with participants as needed. Not only that, the feedback mechanism on TodaysMeet opened up discussions on other technology appropriate for classroom use, a conversation which is still continuing almost a month later!

You can find the presentation at http://box.net/IHSBlog.

APlusPhysics Regents Course Tutorials Completed!

Posted on March 3, 2011 by admin — No Comments ↓

Whew! It’s been a long and challenging project, but I am absolutely thrilled to announce that the APlusPhysics.com Regents Physics course tutorial has been completed (well, at least the first revision). I’ve been done with the tutorial less than 20 minutes, and already I’m making notes on additions, modifications, and enhancements, but I think it’s worth taking a moment to step back and look at everything that’s been accomplished.

A year ago I had never created a web page, and didn’t know the difference between HTML and ELMO. But, with a vision to create a resource specific to the needs of the students I see every day, and with the support of friends and family, I started picking up books, reading web articles, and making many, many designs on paper to script out what I wanted to build.

As of this morning, with the upload of a question bank of more than 500 Regents Physics questions from past years, I’m amazed at how much has been created. The APlusPhysics Regents Tutorials include objectives, explanations, sample problems, FLASH animations, integrated quizzes, videos… just about everything you could ask for in an online resource tailored to a specific course. Further, as the projected progressed, I began to see potential for this resource being used outside my classroom and even outside the scope of NY’s Regents curriculum, and have begun building in further topics of interest to many introductory physics students. Even better, I learned the Regents Physics material better than I could have ever imagined (there’s nothing like digging through 10 years of old exams to help you really learn a course inside and out).

I wanted this website to be an original work, so not only did I learn webpage design, I also had to learn vector and bitmap graphics, flash animation, basic flash programming, and even a little bit of PHP to make everything work in the background. For an artistically-challenged science guy, I’m pretty amazed with the quality of illustrations I was able to create after reading a few books on the modern tools available!

In support of the static web tutorials, the site also features a discussion forum based on the latest version of vBulletin, integrated student and educator blogs, course notes, calendars, project activities, and even hosting for old episodes of the Physics in Action Podcast. So what’s next?

I’ve said from the beginning I want to follow up the Regents Physics tutorials with the AP-1 and AP-2 curricula, but with delays from the College Board, we’re all still waiting to find out exactly what those courses will entail (and to what depth). I have been considering creating a tutorial for AP-C physics, but I’m not certain I see as great a need for such a site, as the AP-C course mirrors many introductory university physics courses, and that material is already widely available throughout the web. With these challenges in mind, I think I’m on hold for creating static tutorial pages for the time being.

This feels like a blessing in disguise, however, as I’ve been quite excited to dive into several other projects. First, I want to expand the build out the Semiconductor Technology Enrichment Program (STEP), a program designed to take the weeks in class after the AP Physics exams and introduce students to basic semiconductor physics and micro/nano technology. Second, I need to spend time planning on the details of the Skills Based Grading (SBG) program I’m planning on implementing in my Regents Physics courses next year. Third, I’d like to continue my work to pre-record video lessons of all the major topics in the Regents Physics course, with the ultimate goal of spending in-class time working on hands-on lab activities, as well as supporting students individually and in small groups, and minimizing the less-effective entire-class-instruction time. Finally, several students have inquired as to whether I might take the course content material on APlusPhysics and expand it into a written mini-book / synopsis for the Regents Physics course. Though initially hesitant, the more I think about it, the more I find value in creation of the written “APlusPhysics’s Guide to Regents Physics.” And oh, by the way, did I mention the list of website enhancements I’ve already started on?

The question, then, is where to start. I oftentimes prioritize items both by “bang for the buck” as well as cost to implement. SBG work will largely occur in late spring and early summer due to some outside interests and external timing constraints. The STEP program may find some external funding in a month or so, and if I can get paid to work on something, why not wait until there’s a bit of income for my time? That really leaves the printed physics guidebook, video mini-lessons, and website revisions. As much as I try to deny it, I know I’ll be working on website revisions by tonight, in tandem with my next project. So which to tackle next, the video mini-lessons, or the printed guidebook? Or both? Would love to hear your feedback and thoughts!

And, as with any endeavor of such scale, allow me to again thank all my supporters, colleagues, family members and contributors. This is a huge milestone for APlusPhysics and the culmination of hundreds of hours of frustration and effort, which has already paid for itself in learning and confidence. I’ve come out all the better for it, and I hope this resource helps others say the same.