Saturday, August 24, 2013

Challenge: A penetrating puzzle that could spin your mind

Apparently today's theme is "Shooting bullets into things... for science!"

Take a look at this mechanics puzzle, presented in a YouTube video. You'll need to render a prediction to see the outcome.

The solution? You're on your own for that.

Hat tip: Laurie Miller Tarr

20 kg of metal at Mach 1 meets 10 Mg of ice

And hilarity physics ensues.

The European Space Agency slammed a jet-pack accelerated, 20-kg "penetrator" into a 10-metric tone ice cube.

They had their reasons.

The impact decelerated the penetrator to the tune of 24,000 gs. Some folks pass out if exposed to 10 gs, and the human body loses structural integrity around 30 gs (300 m/s^2).

In addition to the obvious grooviness, I see introductory physics problems for homework and tests. You?

Hat tip: Phil Plait's Bad Astronomy

Wednesday, August 21, 2013

Why are you spending so much time on kinematics? (The NGSS Edition)

There is a long-standing tradition, in high school physics, of spending the bulk of the first quarter on kinematics. Definitions are slowly pieced together, ticker-tapes are dotted with carbon, motion sensors click away, graphs are drawn, and algebraic expressions are rearranged.

As teachers, we like to assure ourselves of the foundational importance of a deep understanding of position, displacement, speed, velocity, acceleration, and time.

And when one-dimensional kinematics has given its all, we reward ourselves and our students with two-dimensional kinematics. Projectiles are launched, simultaneous equations are wrestled with. And the hunter shoots the monkey.

All this is possible without a hint of Newton's laws of motion. One fourth of the school year sneaks past us while we frolic in 16th-century applied mathematics.

At the end of the year, we lament all the topics that we, again, failed to get to. Darn you, state testing! And snow days! Rainbows? Diffraction? Why the sky is blue? Electricity? Magnetism? Optics? Maybe next year.

At least my kids can solve x = v0t + 1/2 at^2 for t, even when v0 ≠ 0. So... Victory!

Have you seen what the Next Generation Science Standards (NGSS) expect of us in terms of kinematics problem-solving?

Approximately nothing. The first thing NGSS wants us to worry about is Newton's Second Law.

So I pose the query of the post title. And I do so not pretending to be someone who will never go off-script in terms of NGSS. NGSS content is significantly narrower than California 9-12 Physics was.

Where we choose to go "off-roading" in physics content is a value judgment. And I will cover the basics of linear motion. The basics. Not the Complete Robust University Mastery Curriculum. I'll be in and out in two weeks tops. Not six.

And I'll cover other, groovier topics not mentioned in NGSS. Some people naysay forays beyond the realm of the FCI as curriculum that's a mile wide and an inch deep. I disagree.

If NGSS needs essentially nothing in terms of kinematics, how can you justify forfeiting up to 25% of your academic year to it? I honestly don't think you can. But I've been wrong before.

Bear in mind my inquiry regards plain old high school physics. Not AP or IB. But please don't be put off by my polemical tone. That's just how I am. If you think I don't know which way is up, feel free to slap me silly with the power of your arguments. I can take it!

Saturday, August 10, 2013

Challenge: Crazy bell schedule shoot-out!

When I arrived at Rio Americano in 1986, the school had a bell schedule I didn't expect.

Mondays, Tuesdays, and Fridays were traditional 6-period days, but Wednesdays and Thursdays were "block days": the bells rang at the same time, but students would attend—on Wednesdays—1st period for two hours, then 3rd period for two hours, then 5th period for two hours. On Thursdays, it was 2nd, 4th, and 6th periods for two hours. The passing period served as a optional break to be used or not at each teacher's discretion. There was also a 10-minute "nutrition" break added to the passing period between 2nd and 3rd period (and between the morning blocks).

The block period was generally popular with science and language teachers, and generally unpopular with math teachers. From time to time over the many years of my tenure, the faculty was asked to vote on whether or not to continue the block schedule. The block won every vote. As more votes were held, the block's margin of victory increased.

Then it was decided that all schools in the district would implement "faculty collaboration". Districtwide, all school's would release students early on Thursday; Thursday became the "short day".

So we had to move our blocks to Tuesday and Wednesday. (A vote to discontinue the block was held; again this push failed.)

Then it was discovered that due to the logistics of administering state-mandated tests that are not given to seniors, our schedule fell short of the state-mandated number of instructional minutes. So mid-block breaks were eliminated. That meant six fewer bell-rings on block days, but the other bells rang at the same time.

Next it was decided that if we increased periods by a minute and reduced our mid-morning break, already down to 8 minutes down to 5 minutes), we could legally allow seniors not to attend school during the administration of state-mandated tests they could not take. Otherwise we would need to warehouse them during those hours.

This brought a bit of "pain" to teachers and students every school day of the year, but eased the administrative burden to the school during April's test week. After trying that for a year, teachers voted to abandon it so as to restore the mid-morning break.

But instead of returning to the schedule we used two years ago, it has been decided that we need to do this:

1 7:50 - 8:49 7:50 - 9:53 - - - - - - - - 7:50 - 8:37 7:50 - 8:49
2 8:54 - 9:54 - - - - - - - - 7:50 - 9:53 8:42 - 9:30 8:54 - 9:54
3 10:06 - 11:06 10:07 - 12:11 - - - - - - - - 9:42 - 10:29 10:06 - 11:06
4 11:11 - 12:11 - - - - - - - - 10:07 - 12:11 10:34 - 11:21 11:11 - 12:11
5 12:46 - 1:46 12:48 - 2:50 - - - - - - - - 11:26 - 12:13 12:46 - 1:46
6 1:51 - 2:50 - - - - - - - - 12:48 - 2:50 12:48 - 1:35 1:51 - 2:50

While this is the craziest bell schedule I've encountered in my 27 years of teaching, it may not be the craziest bell schedule out there.

I challenge you to present a crazier, verifiable high school bell schedule.

My verification link: Rio Americano Bell Schedule. (Lest you think I was making this up.)

Friday, August 09, 2013

California Physics: Gem of the state-mandated science tests

The data is in for what appears to be the last round of end-of-course content standards tests.

And in science, Physics finishes on top!

Here are the 2013 Advanced and Proficient percentages:
Biology: 49%
Chemistry: 40%
Earth Science: 37%
Physics: 53%

While CSTs were first administered in 2001, the California Department of Education uses 2003 for its baseline data.

Here are the 2003 numbers for comparison:
Biology: 37%
Chemistry: 31%
Earth Science: 21%
Physics: 29%

Here are the year-by-year numbers with trendlines.

While the other science CSTs were going down, Physics managed to go up!

The award for highest proficiency rate goes to... Physics with 53% in 2013.

The award for most-improved goes to... Physics for posting a 24-point improvement from 2003 to 2013.

Are there other ways to analyze the data? Yes. Even to the point that Physics isn't the science winner? Yes. Am I going to elaborate on those? No.

Congratulations California public school physics teachers: you are—objectively—the best!

To access your school's 2013 STAR results, start at the 2013 STAR Test Results page. From there, select your county, district, and school. Then click the "View Report" button.

To see district, county, or state results, simply leave deeper fields unspecified.

Thursday, August 08, 2013

Rio's 2013 Phyz students are best ever

Rio's 2006 Phyz students held the top spot for six years. They scored as 72% Advanced or Proficient in Physics. With the STAR program's End Of Course (EOC) California Standards Tests (CSTs) winding down, this year's classes rose to the challenge. They will go down as Rio's best physics students ever, as measured by the state of California.

The physics students of 2006 had edged out those from 2001 by  single percentage point.

The physics students of 2013 eclipsed 2006 with a stunning 77%!

Forty-one percent performed at the Advanced level; 36% came in as Proficient. Seventeen percent were rated Basic, 2% Below Basic, and 3% Far Below Basic. (Due to rounding, this does not add to 100%.)

I'll update this post with graphics and more analysis eventually. For now, I'm going to enjoy the buzz.

And congratulate Rio Phyz 2013 as our best physics students ever!

Click here to see if this takes you to schoolwide results.

UPDATE: As promised, here is a breakdown and some longitudinal context for the 2013 data.

We begin with the most detailed breakdown: the number of students at each performance level. Performance levels are Advanced, Proficient, Basic, Below Basic, and Far Below Basic.

Rio Americano/Baird Student Performance, 2008-2013

This analysis leaves something to be desired. There's too much data to see larger, more important trends. A more telling chart compares "good" to "bad". That is, the numbers of proficient (or better) students to the number of basic (or below) students. This chart captures the relative proportions and the overall sample sizes from year to year, and is therefor the most useful chart for analysis.

Rio Americano ADV+PRO vs. BAS+BB+FBB, 2008-2013

Boiling it down too far yields a simple "horse race" result: what percent of the school's test-takers were either advanced or proficient. You lose sample size data here, so things can be somewhat misleading.

Rio Americano %ADV+PRO, 2008-2013

If this chart makes it appear as if 2012 in an anomaly, that's because it was. Rio did not have AP Physics in 2012. We will not have it in 2014, either. But EOC CSTs appear to have run their course, so no worries.

Rio's Physics CST proficiency rate of 77% stands as the highest mark among all the EOC tests. No other CST administered at the school had better results.

Districtwide, our 77% rate places us third among our nine comprehensive high schools. My hat is (again) doffed to Bella Vista and Mira Loma for their physics awesomeness.

Can too much emphasis be placed on the proficiency rate? Absolutely. An arguably better metric is the proficiency number: how many students scored as proficient or better. Rio's biology proficiency rate is always at or near the top for the school. While the physics rate of 77% is better the biology rate of 63%,  biology's proficiency number (63% of 521, which is 328) far outshadows physics' proficiency number (77% of 87, which is 67).

Still though, as a school, we end the Physics CST era on the highest note we've ever played.

Wednesday, August 07, 2013

AP Physics Hall of Fame updated

Today we welcome six new members to Rio's austere AP Physics Hall of Fame. They are

Ivan Cherkashin
Ramsey Karim
Patrick McClure
Scott McCuen
Aaron Prohofsky
Tyler Reeves

Congratulations! I'm not sure of the exact extent to which this feat distinguished them from the rest of humanity, but Physics is far from the most popular AP exam, and the air gets mighty thin at the altitude of AP Physics 5-ers. The accomplishment is noteworthy and praiseworthy.

The Rio Phyz Hall of Fame is posted at my Phyz site and stretches back to 1987, when the first of my students sat for the exam.

All Rio's AP Physics B candidates received passing scores of 3 or better this year. Again, this is not a simple matter. I am proud of all my 2013 AP Physics examinees!

Prop 30 budget cut fears wreaked havoc on this spring's final exam schedule. So I don't have a single AP Physics group shot. But here's one with many AP Physics students. More can be found in the 2013 Rio Phyz album at Flickr.