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30 January 2018

US Invitational Young Physicists Tournament 2018 results and 11-year participation

A big thank you to Randolph College in Lynchburg, Virginia for hosting the 11th annual US Invitational Young Physicists Tournament.  This past Saturday and Sunday, a record fifteen teams competed in physics fights over four problems involving:

     * measurement of the moon's orbit
     * electromagnetically coupled oscillators
     * blackbody radiation laws applied to light bulbs
     * projectile motion in air

This year's winners, in their third visit to the tournament: Phillips Exeter Academy of New Hampshire, led by physics teacher Scott Saltman.

In second place was The Harker School of California, led by Mark Brada and Miriam Allersma.

The winner of the Swartz Poster Session was Shenzhen Middle School, led by Chen Shaorui.

The overall order of finish is below.  Our rules state that a number of places are shared by similar teams.  The ** means that this team won the prestigious Bibilashvili Award for outstanding physics.  It is awarded to teams with superior physics understanding, irrespective of their placement, at the tournament director's discretion.

     Phillips Exeter Academy**

Second place:
     The Harker School**

Third place:
     Rye Country Day School**
     Cary Academy**
     Yorba Linda High School**

Fourth Place:
     High School affiliated with Renmin University, China

Fifth Place:
     Shenzhen Middle School**

Sixth Place with Bibilashvili Medal:
     Woodberry Forest School**
     Nueva School**

Sixth Place:
     Pioneer School of Ariana
     Qingdao No.2 High School
     Vanke Meisha Academy
     Princeton International School of Science & Mathematics
     Spartanburg Day School
     York Country Day School

And scroll down to find the list of all teams who have participated in the USIYPT since its inception in 2007.

Next year's tournament will be January 26-27 at Rye Country Day School in New York.  If you'd like to come as a juror - or if you'd like to bring a team from your school - please email me.  More information about our tournament is available on the official website,

Participating USIYPT schools in the 11 tournaments since 2007:
The Harker School, California – 9 tournaments, 3 championships
Rye Country Day School, New York – 11 tournaments, 2 championships
Shenzhen Middle School, China – 7 tournaments, 2 championships
Woodberry Forest School, Virginia – 11 tournaments, 1 championship
Phillips Exeter Academy, New Hampshire – 3 tournaments, 1 championship
Brisbane Girls Grammar School, Australia – 2 tournaments, 1 championship
Raffles Institution, Singapore – 1 tournament, 1 championship
Pioneer School of Ariana, Tunisia – 6 tournaments
Nanjing Foreign Language School, China – 5 tournaments
Princeton International School of Science and Mathematics, New Jersey – 4 tournaments
High School affiliated with Renmin University, China – 4 tournaments
Cary Academy, North Carolina – 3 tournaments
Phoenixville Area High School, Pennsylvania – 3 tournaments
Wildwood School, California – 3 tournaments
Oak Ridge High School, Tennessee – 2 tournaments
North Carolina School of Science and Mathematics– 2 tournaments
Oregon Episcopal School – 2 tournaments
Vistamar School, California – 2 tournaments
Guilderland High School, New York – 2 tournaments
Qingdao No. 2 High School, China – 2 tournaments
Vanke Meisha Academy, China – 2 tournaments
High School of Jur Hronec, Slovak Republic – 1 tournament
Calverton School, Maryland – 1 tournament
Madeira School, Virginia – 1 tournament
Pioneer School of Manzeh 8, Tunisia – 1 tournament
Georgian English-Spanish School, Tbilisi – 1 tournament
The Nueva School, California - 1 tournament
Spartanburg Day School, South Carolina - 1 tournament

Participants, team leaders, and jurors at the 2018 USIYPT at Randolph College

20 January 2018

Guest Post: Bill Payne on using Audacity as a timer

Folks, Bill Payne submitted a note to the Modeling listserv that'd I'm sharing with permission as a guest post.  I always love using free software to get data that otherwise would require expensive commercial apparatus; Bill has a fantastic method of determining time intervals to millisecond precision using audacity - google "audacity" to get the free download.  Bill also provided a link to a set of follow-up questions in this excel file.  Take it away, Bill:

Bill: My kids and their teacher love shooting darts, both the kind with the suction cup end and the round end.  Last week we used the computer program Audacity to time how long it took a dart to reach a target 1 m, 2 m and 3 m away.  Audacity will give the time in milliseconds between any two sounds: the firing of a dart gun and the dart hitting the target, or you can roll a steel ball down a ramp, see where it hits the table, and place a whiteboard a measured distance from the point the ball hit the table.  Audacity is much easier to set up than photogates, and it's a free download.

Audacity will let you highlight and delete the parts of the graph you don't need, such as the flat line leading up to the firing of a dart gun.  That sets the time of the firing of the gun to zero.  Then expand the graph with Command 1 to stretch it out (repeat Command 1 to stretch it out more and more).  Cut the rest of the leader out to get the firing right on zero.  Then put your cursor on the beginning of the part of the graph when the dart hits its target, and read the elapsed time at the bottom in milliseconds.  Calculate velocity: V = d/t.

Only problem is, now the kids want to have a dart-gun war.  I put them off to the end of school.  :-)

Bill Payne
Physics Teacher
Host of modeling workshops at Birmingham-Southern College

16 January 2018

Trust the Process

I had a rough class Tuesday.

I thought about changing course.  I didn't - I kept plunging forward.  And everything worked out beautifully.

We were working on the direction of force and motion using these in-class lab exercises.   I encourage you to take a look.  They involve three situations:

1. Jumping on or off a force plate
2. A hanging object attached to a cart
3. A fan cart attached to a hanging mass over a pulley

In each case, two forces act on an object.  Students are asked to determine the direction of acceleration, and then which of the two forces is larger.  Finally, they go to the back of the room where I have equipment set up.  They use force probes and plates to verify their predictions.  Nothing here is quantitative - we don't predict a value for the tension in a rope.  In this exercise, we only are comparing which of two forces is larger.

Sounds easy enough, right?  "The object moves up and slows down, so acceleration is downward.  Net force is also downward.  That means down forces are bigger than up forces, so the weight is bigger than the tension in the rope."

Hah.  No, on Tuesday I kept hearing "In order for the object to move upward there must be more forces pulling than pushing upward than downward.  And the object has weight, so the tension in the rope is massive.  Plus here are three more sentences full of nonsense please count it right."  I'm barely making this up.  My class was getting palpably frustrated.

In 80 minutes of lab work, about half the class completed one exercise; the other half completed zero.  I had a major assessment scheduled for the last part of Thursday's 90 minute class.  Would the students be ready?  Should I reschedule?  Should I stop the lab work and start just doing problems in front of the class to assuage their frustration?

It's hardly ever a good idea to slow the pace of the class just because students seem to struggle the first time seeing a difficult concept.  If Newton's second law were easy, I wouldn't be employed. Doing problems in front of the class doesn't help anyone - the only way to learn physics is to make mistakes, then to learn from those mistakes.  Students must be active, not passive, otherwise they'll make the same mistakes on the assessment that they were making in class.

So I pushed on.  Thursday's class began with a brief quiz, followed by five minutes of discussion about the problem set.  Then back to lab work for 45 minutes before the major assessment.  I braced myself...

The pace of work ascended to the next available energy level.  Everyone finished at least two exercises.  About half the class finished three.  And scores on the major assessment were as high or higher than ever.

Trust the process.  When you're doing creative lab work, or any sort of physics teaching that isn't just you telling students how to do problems, frustration and wrong answers are a natural part of the learning process.  Let that frustration happen.  Keep morale up as best you can.  Because the epiphany will come.

And what of the two or three students who didn't perform well on the assessment?  Wouldn't they have been better served by a different approach?  Perhaps, but not likely.  In any case, their epiphany will come, too.  In fact, during the next Monday's test corrections class, one of these three poor performers looked at me with a wry smile.  He said, "you know, I kept making dumb mistakes.  I should have known these answers, they seem really easy now.  I'll get these next time no problem."