Day 61: 30 Minute Classes–again

The day before Thanksgiving break and we have an early release for students and a PLD for the staff.  This means 30 minute classes in the morning, and meetings in the afternoon.  The afternoon meeting included an overall of the philosophy of our Reading Specialists (~20 minutes) and then more information from our LMS expert about Schoology, our districts (purchased) LMS.  I really like Schoology as an LMS.  It is worth taking a look at if your district is not using one or is looking for a different one.  The rest of the tie was departmental so we worked on re-evaluating the benchmarks for each course (even though we are not quite ready for SBG) and assigning a DOK (Depth of Knowledge) to each, then planning common assessments for each.  One of the things that came out of the discussion  I was part of was that there is much work to be done.

So with 30 minutes, what did I do in my classes?

Advanced Physics:

Discussed the problem set from the Projectile Motion assessment.  I always re-write each problem so my students can keep them, and everyone now and then I screw up.  Here is an example:

1.     Remember the angled Monkey and Hunter demo? Imagine that I wanted to use the Mini-launcher rather than the blowgun (I know, not nearly as cool, but…). Some details:

·  It is aimed up at a 30o angle.

·  It’s the third setting, so the launch velocity is 5.20m/s

·  The monkey hangs at a height of 1.25m

If the monkey is to be hit when it is 15cm above the table, how far away, horizontally, should the mini-launcher be placed?

If one solves it by finding the time it takes the monkey to fall to the 15 cm height, the time =0.473s, if one solves if find the time it takes the monkey to have a change in height o 15 cm, the time is  0.464s, and it one graphs it (or solves it kinematically), the time is 0.48 s and the two collide at a height of 11.8 cm.  I was perplexed by this so I sent it out to a few colleagues from of Phox Share group.  One of them replied (4 times) and in the ned realized my mistake.  The monkey and hunter demo makes two assumptions, (1) the two are released at the same instant, (2) the hunter aims at the monkey.  The 30o angle is does not aim at the monkey when it is at a height of 1.25m, it’s close which is why the times turned out so close.  I proposed this to my 3 sections and asked about the problem.  One student in my mod 2 class saw it right away! AWESOME learning experience, and nice for all the students to see that I still make mistakes too.

General Physics:

We reviewed the ramp lab and then used the same video analysis sequence I used with my advanced kids to transition from position and velocity graphs to acceleration graphs.  Al qualitative right now.


Day 60: Forces Diagnostic and WB the Ramp Lab

Advanced Physics:

Today I gave a (the) 30 question Forces Diagnostic Assessment. Although I am not using the results for part of my SLO this year, I am using it to help me plan instruction. The most missed question dealt with N2L and the summation of forces.  The overall pre-test average for the all three sections this year was 14.  Seems higher than in the past.

After this was completed, we finished discussing the conceptual part of the projectile motion summative test.

General Physics:

Today we WB’ed the ramp lab results.  The instructional goals were: (1) qualitatively develop the  concept of acceleration as the slope of the v-t graph and how the velocity changes each second, and (2) qualitatively develop the concept of instantaneous velocity as slope of a line tangent to a non-linear position-time graph.  We are not going to develop any of the kinematic equations for constant acceleration until the end of the unit.

Day 59: Summative Projectile test take 2, the ramp lab

Advanced Physics:

Today was only two problems for the problem set part of the summative test over projectiles.  One horizontal launch and one angled launch.  The horizontal launch was the popular Speed (movie) problem— assuming a real horizontal launch, how far does the bus drop?  One of the angled launch choice was not overly challenging IF the students thought carefully about the situation.  They did not need the vertical velocity at all to solve it…. how far away should the launcher be to hit the falling monkey when it is 15 cm above the table.


SIDEBAR:  Some students really like having the two parts of the test split… I ay have to think about this a bit more.


General Physics:

Today was all about gathering data for the ramp lab.  We may not have gathered the best data.  Dynamics carts a re a bitt too fast with the short ramps, and some of our toy cars are not the best.  Might be time to build some of the constant acceleration disks or invest in the Motion Encoder system from Vernier?  Tomorrow we WB the results.

Day 58: More Ring, Testing and Another Ramp

Advanced Physics:

In each section, we had a few groups that still needed to set-up and test the Ring of Fire.  After they were finished the students completed the conceptual part of the summative test.  There was 11 MC (even some angry bird questions) and one set that dealt with a projectile launched at a smaller angle (less than the 45 degree first launch) .. sketch and explain the new horizontal position and vertical velocity graph.  This was harder for my students than I though it should have been.

General Physics:

We discussed the constant velocity summative test and started the pre-lab discussion for the ‘ramp’ lab.  The version of the ramp lab we do with the general physics students is not the full-blown ramp lab we do with the Advanced students.  We do not have the use photogates or watches to gather position – time data.  We use a motion detector to go right to the non-linear position -time graph and the linear velocity-time graph.

Day 57: The Ring of Fire

Advanced Physics:

As explained yesterday, today was spent checking the  Stunt Barbie – Human Cannonball-Ring of Fire predictions.  Why Ring of Fire you ask….  here’s why:

And of course Johnny Cash playing in the background.

General Physics:

Unit 1 (Constant Velocity) Summative Test… hoping for good results.

Day 56: A Challenging Day

Advanced Physics:

Today the students took a one problem projectile assessment and gathered the data necessary to complete a projectile motion challenge lab.  Here is the Stunt Barbie- Human Cannonball challenge.  Tomorrow we check it.

General Physics:

We spent today checking the buggy challenge lab. There were a few groups that were pretty close, but most were more than 20 cm away. I think it must be a result of the batteries draining a bit during the three mods that used them… next year, cells for each group I think.  Here is one of the better results:

Day 55: Projectile Motion Problems and Buggy Race Challenge

Advanced Physics:

This class was spent WB’ing four of the six projectile motion problems they had been working on.  I choose one of them; a goalless problems as described by Kelly O’Shea here.  I like these because they can get us away from specific types of problems and pose some really interesting ones.  I usually use one of them as some extra practice during class or as some at home practice.


General Physics:

We are nearing the end of the constant velocity unit, so it is time for a Challenge lab.  The one I choose this year was to race the buggies side-by-side but the need to cross the finish line at the same instant.  Each group can use two buggies but only one at a time.  There get a slow one (one cell with a slug in place of the other cell) and a fast one.  They can determine the velocity using any of the methods we have used so far… measuring positions and times, or video analysis, or even with the motion detector. The students use the velocities to determine the starting positions.

Day 54: Loose ends

Because I was un-expectedly gone on Friday, today was a chance to get caught up with the students.

Advanced Physics:

When I was gone, they worked in small groups on a set of 6 projectile problems.  I received emails from three students asking if they needed to finish the work over the weekend (I love it when students are responsible).  I knew they did not finish from the notes my sub left.  I had planned to give them about 1/2 the class period to finish, but they worked hard and asked for help the entire time.  Who can argue with that!

General Physics:

They also worked to finish the practice I had them complete when I was not there.  This group was working on solving constant velocity problems involving two objects using position graphs.  They also needed all the extra time because I had waned them to use Logger Pro to create the graphs.

Day 53: Group Problem Solving

I was not in school on Friday.  The plan for both the Advanced Physics course and General Physics course was the same; group problem solving.  The Advanced assignment was a set of six projectile problems, while the General assignment was a set of three constant velocity problems that were to be solved graphically.  While I sometimes cringe at using an entire class period on this type of assignment, many of my students love this type of day.It allows them to practice solving problems and get help at the same time. In a sense it is what many of us crave…extras time to work. I suppose it is like a teacher getting an extra prep hour.

Day 52: The Monkey and the Hunter Take 2; Odd or Even?

Advanced Physics:

Today was all about projectiles launched at angles.  We revisited the Monkey and the Hunter question; this time with the Monkey in the tree and the Hunter on the ground.  Same question… where to aim?  Back to the actual set up:

General Physics:

Today we combined all three constant velocity representations… position graphs, velocity graphs, and a written description.  Each group was given one of the three and was asked to create the other two.  After it was presented, the group rolled a single die.  If it came up as an odd, the group modeled it by walking it, it it came up and eve, the had to create and tell a story about it.