## Monday, July 2, 2012

### I've Moved

After reading and writing comments on blogs everywhere, I've moved my blog over to wordpress.  You can see my newer posts here

## Friday, May 4, 2012

### Flipped (?) Review

I'm not going to make this an overly long post, as it's the end of the school year, and there's no time to be overly verbose.  To quickly get to the point, whenever you get a new toy, you want to play with it as much as possible.  Well, I'm happily looking for was to play with my new iPad (yeah, here comes the spam).

This year, I've been using some of the tools from Modeling whenever possible, one of the most common I've used being whiteboards.  As I get ready for review for finals, I was trying to figure out how to effectively use whiteboarding to review for the exam.  For most of the year, I've asked the students to take pictures of their whiteboards at the end of discussion and post them into the class Schoology page.  The main problem with that is that most haven't done that.

So, insert "I-want-to-play-with-my-toy,-so-let's-see-if-we-can-make-it-effective."  I've uploaded a .pdf of the review questions I assigned into an annotation app (uPad Lite - I'm cheap and it's free).  My thought is I'll be the secretary that writes the minutes and they'll whiteboard the various problems.  Then I'll post the minutes into schoology so everyone has the results.

The kids will do the explanation, and I'll take notes.  That's my take on a flipped classroom.

p.s.- yes I would love to have the kids do this, but we currently have a no mobile device policy and no wifi.  I tend to look the other way for the kids that actually take the time to take pictures to post online when they get home.  This policy is most likely changing for next school year, so part of my reason for doing this is to begin trying somethings out.  Any thoughts on better ways to do this would be greatly appreciated!

## Tuesday, March 6, 2012

### LOL Energy Diagrams

As I've gotten more into using blogs and twitter as a teacher, I find that they are both such an amazing learning tool for me. This post will make a lot more sense if you read Kelly O'Shea's blog on LOL Diagrams.  As you can see by the comments I made I was taught a slightly different way of making LOL Diagrams in my modeling workshop (See here).

For the following problem:

Here's how I would use LOL's to solve it.  I would first state what objects are in my system (in this case, the spring, the cart, the earth, and the track). I would then  draw the following LOL diagram.

As you can see, the "L's" are exactly the same, however in Kelly's format, you show the objects in the system versus those out of the system.  In this style you show the flow of energy as you move from the initial state (in this case, the energy stored in the compressed spring) to the final state (the cart moving at the top of the loop).

Kelly later gives an example of what the LOL would look like if you do not include the spring within your system.  Here's my take:

Since the spring is no longer part of the system, some "outside object" is doing work on the system.  Also, since the spring is outside the system, it doesn't matter if it's a spring or a rocket or anything else, "something" is providing work to increase the energy of the system.  The way my thermo teacher in college summarized it, if you care what did the work, include it in your system, but then it's not work.

{If that doesn't make sense, if the source of "work" is the spring, then you would call it elastic potential energy or spring energy.  If it were a rocket, you would call it chemical potential energy. etc.}

If we go back and include the spring, but also include friction. Then your LOL diagram would look like this:

As I mentioned in my comment to Kelly's post, I think either method could work. To me, this method makes more sense given the "O" in between the "L's" since it shows how you are getting from the initial to the final state.  I think if you are using Kelly's method, the "O" should go before the first "L".

I'll be the first to admit that I'm learning a lot more from her blog, then I've even thought of sharing on this one.  Just wanted to try to show what I was trying to say.  I'd love to hear from other experience modelers as to which style they use.

## Wednesday, February 8, 2012

### Legend of the Teacher

Now that I'm able to blog again, one thing that has been taxing my thoughts is my school's ongoing switch to the "Common Core."

{A little background}
My school has always (at least as long as I've been here) had learning objectives for each class.  Since we are a private Catholic School, we've had the freedom to set our own objectives (in collaboration with the other Catholic HS in our diocese).  Although we used the state and national standards as a point of comparison, we were free to write our own objectives for the course.  The good thing about this was the freedom to mold the course the way we as teachers wanted it to be.  The downside was that we had to meet every five years to edit and revise those standards.  Over the last year or so, our diocese has decided to adopt the Common Core standards as they emerge and be in compliance (if that's the right phrase) within the next 2 or 3 years.

So where does "School of Rock" come in? One, it's an awesome movie, so why shouldn't it be there. Two, I think the chorus of the song can be slightly modified to explain some of our struggles with adopting the common core.  I think you have to live the "Common Core" before you can teach the "Common Core."  What I mean by that is, most teachers fall into the trap of teaching how they were taught.  I reading the various posts on education reform, most teachers would agree that there's always some new thing that comes out.  By the time you fully switch to it, the new flavor of the month comes around and now you are to switch the that new thing.

As I interact with teachers, I think they see this switch to "Common Core" as just one of those new flavors of the month.  They see a new set of standards, not a new mentality for teaching.  To me, the shift of the "Common Core" is about changing the dynamics of the classroom.  No longer is my job to be the "Sage on the Stage," but rather the "Guide on the Side."  (Sorry, I forgot from whom I stole that, but it's definitely not mine).

Since "all" of us have had teachers that were the "Sage on the Stage," they see this new change as just changing what they teach, not how they teach.  As I've gotten more involved in the Modeling, I am beginning to appreciate, what I see, as the true changes for "Common Core."  After going to the modeling workshop last summer, I was able to be a student in a class where the teacher didn't "teach" us anything, but rather created activities, and guided us through them.

I remember talking with some of the other "students"  the first few days about our frustration with the fact that they weren't teaching us the "Modeling Method."  After we got into the 2nd unit, it dawned on me, that the only way to truly teach by experience, one must first learn through experience.  I think that is truly the "Ah Hah" moment that teachers talk about after going to one of these workshops.  It finally clicks that true teaching is in creating the experience and knowing where the tough spots are, not how many cool facts you can tell your students.

You've go to learn "Common Core," before you can teach "Common Core."

## Thursday, October 13, 2011

### Conservation of Energy Lab

I saw a question today in twitter:

Modelers: how do you develop 1/2mv^2 from lab? how do you develop mgh from lab?
At the modeling workshop this summer, we did exactly that,  however, instead of just rehashing that post, (you can read it here), I figure I would tell you how I tweaked the experiment for my AP class.

Since my AP-B class is a second year class, my students already have a working idea of the relationships (as time goes in and I fully switch to modeling, they should know the models) from the first year.  So instead of using the labs as a discovery of the relationships, I like to have some challenge in the lab in which the students have to predict something using their data.

Here's the setup:
Equipment
vernier cart
vernier track
vernier spring launcher
motion detector attached to track opposite the launcher

Set up the track at an angle (ie - place a book under one end of the track)

Using LoggerPro and the motion detector, pull the cart back to compress the spring and let go.  Stop the detector after the cart has reached it's highest point on the track.

The Analysis:
Have LoggerPro display a position vs time and a velocity vs time graph.  From the velocity vs time graph, highlight the data, and use the "Statistics" function.  The minimum value will be the compression ($\Delta x$), and the max value will be the maximum displacement ($d_{max}$).  Highlight the data from the velocity vs time graph, and the maximum value is the maximum velocity ($v_{max}$).

(Note- if you want to do so, you can have the kids look at what position the max speed occurs (x=0)

Repeat the procedure several times, recording $\Delta x$, $v_{max}$, and $d_{max}$ into a second data set.  Plot $d_{max}$ vs $\Delta x$.  Have the students linearize this first graph, and they should see that $d_{max}$ is proportional to $\left( \Delta x \right)^2$.  Now plot $v_{max}$ vs $\Delta x$, lead student to plot $\left( \Delta x \right)^2$ on the x axis, since that will allow this graph to relate to $d_{max}$.  They should find that they need to plot $v_{max}^2$ on the y axis.

(If you want to take it a step further and include the masses to fully develop conservation of energy, go for it.  As I said, my kids already knew those relationships from last year)

So here was my twist, how do you relate the maximum displacement to the vertical height?  Since my students knew the energy relationships, I had them use their data and trigonometry to calculate the angle of the track.  Just to give you heads up, here is what they should get...

From trigonometry, you know:
$h_{max}=d_{max}sin \theta$

And since mass is used for both kinetic and gravitation energy, you can rewrite the energy conservation as:

$g*d_{max}sin \theta = \frac{1}{2}v_{max}^2$

Therefore:

$\large \theta=arcsine \left(\frac{g*d_{max}*v_{max}^2}{2}\right)$

I then measured the angle of the track using a level app in my iPhone to compare the actual angle to the one predicted by the groups.  The app I has was able to measure to the tenth of a degree.  Most groups were able to get within $0.5^o$ of the value measured on my iPhone.