Archive for the 'Physics' Category

The Beginning of Year 5

Today was really weird.

So for the past 2-ish weeks, I’ve been at our brand-spanking-new high school building.

I unpacked all of my stuff and made it look presentable.

I put posters everywhere.

I did my pre-planning.

But today the students arrived and it finally became real for me.

This was my new classroom.  These are my new classes.  I have some pretty big changes planned.

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Geogebra: Eratosthenes

This year, my school is doing a Bring-Your-Own-Device initiative.  I’m super excited because it means that I can use GeoGebra and Desmos in class!

One of my favorite things to do in Physics is to discuss Eratosthenes’ estimate of Earth’s Circumference.  It’s a good early activity to check how much they remember from Geometry, and show them an example of how math knowledge can be applied to solve real world problems.  I think this year, it will serve as my intro to GeoGebra too!

Problem:  

Eratosthenes calculated the circumference of the Earth from his home in Alexandria.  In the city of Syene to the south, there was a deep well that served as a landmark.  Eratosthenes knew that on one day each year, at noon, the sun would be directly overhead, and the water below could be seen.  (This day was the longest day of the year, the summer solstice.)  On this day, in Alexandria, Eratosthenes went out at noon, and observed the shadow of a vertical landmark.  The angle between the base of the landmark and the end of its shadow was measured at 7.2 degrees.  Eratosthenes estimated the distance between Alexandria to Syene, and used these values to make his calculation.

    • We will estimate the distance from Syene to Alexandria as 800 km.
    • We will assume the Earth is a perfect sphere.
    • We are going to ‘guess’ the radius and circumference of the Earth, and use Geogebra to match our situation to Eratosthenes’

Click the picture to go to my Geogebra file

Eratosthenes 1

Extension:  The sun’s rays can be adjusted to show how to solve this problem with shadows in both cities.Eratosthenes 2

Baby Steps toward a Paperless Physics Class…

This is a thing I’ve been secretly working on for weeks, but it has become more relevant in the last few days.

Yesterday during our daily announcements video, our principal announced that there would be no backpacks in the halls or classrooms once we move to the new school building.  (Students can bring backpacks from home and leave them in their lockers, and then pick them up and use them to take stuff home at the end.)

My freshmen seemed pretty neutral to the idea and didn’t have much to say as they watched the video.  However, my juniors in physics had a lot to say about it today.  They really wanted to know how I felt.

I understand that these are the kids who probably have 3 or 4 monster textbooks to tote around (mine being one of them).  I also understand that most of these teachers require separate notebooks or binders.  (Again, guilty as charged…)

So I was honest with them.  I asked them to look in my corner behind my desk.  There lies my green and grey plaid backpack.

“See, even you have a backpack!”

I confessed that I did.  Teacher’s editions are heavy, and carrying them around used to be a pain in the butt.

Then my second confession:  My backpack hasn’t gone home since Thanksgiving break.  I’ve switched to using the .pdf version of the textbook.  I have copies of everything on our school’s Microsoft One Drive.  It’s awesome because I can literally stop working after school, walk home with nothing, and have access to all of my resources on my home computer (if the urge to work strikes).

In my own self-contained teacher bubble, I am paperless as I plan and build assignments.  However when I get to work, I make copies and distribute textbooks like everybody else.  Our school is an older building, the wifi isn’t great.  I share my laptop cart with two other teachers.   Not every student’s phone runs the same operating system.

It was really easy to use these things as excuses as to why I couldn’t go paperless with the students!  But the more I think about it, they are just excuses and can be overcome.

We are moving to a brand new building next year so (hopefully) the wifi will be better.  The reason I mention the move is that it’s made me lazy.  I look at the things I need to pack and think ‘I just don’t wanna!’

So out of laziness, I put on my thinking cap and decided to do what I could with One Note and One Drive.  If I can digitize some stuff, I can travel lighter, right?

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Let’s talk Collisions…

I’ve been working on renovating my new house for the last month.  This is moving week.  I feel like being sleep-deprived and tired is no excuse to have a lackluster physics lesson, so I started googling.

First off, I’d like to say that aplusphysics.com is downright awesome.
I looked at the above car crash web-quest and thought about assigning it to my classes as-is, but I’d like to give my spin.

My physics students were given 5 problems to try in groups of 3.  All collisions involve a car at rest getting rear-ended with both cars sliding forward.  My students are very advanced, but they are still somewhat averse to researching to find their own information.  So I took this basic premise of a car accident and decided to come up with 5 similar problems for the one direction.  The major question remained the same:  Was the driver who caused the accident speeding on impact?

I assumed ideal road conditions and no friction.  To make it more interesting, I looked up celebrities and their various cars to use them as the characters for each story.  Each accident had different sliding lengths and different posted speed limits.  I provided no pictures, just verbal descriptions.  I tried to write my problems like an American news story, so all speeds are in mph, and all distances in feet.

My students needed to use the web to find the approximate mass of the celebrities and their cars, and the braking distance for each car (from 60mph to 0).  From that they could estimate the acceleration applied by the brakes, and work backwards from the sliding distance to find initial velocity following impact.  One the impact velocity was found, the groups could use conservation of momentum to find the velocity of the first car before impact.

I understand that these are pretty idealistic conditions, and that celebrities probably don’t wail on their brakes with perfect reaction time in an accident, but this actually gave my classes even more to discuss!

I also didn’t assign jobs to the students, and was a bit more lax on presentation requirements.  I have one group bringing in lego constructs to re-enact their crash, and another is using posterboards and easels to show the accident and their calculations.

Example problem:

Somebody call the paparazzi! Paris Hilton has been texting while driving again! Thus far she has been able to keep her driver’s license and avoid jail time by using her tremendous wealth to hire the best legal defenses. Unfortunately, she’s been involved in a car crash with another celebrity!

 

Paris Hilton, driving a 2014 Luxury Cadillac Escalade with 2 wheel drive, rear-ended Justin Bieber’s Ferrari 458 while he was stopped at a Hollywood Boulevard stop sign. The two celebrities were the only people or objects in the respective cars, and the vehicles were presumably brand new.

 

Justin Bieber is FURIOUS!

 

The officers have already charged Paris with texting while driving, but if Bieber’s defense team can prove that she was going more than 10 miles per hour over the posted speed limit before impact, then Paris will lose her license.

 

Police have determined that both vehicles slid in a straight line after impact, and were NOT attached to each other. Bieber and his Ferrari came to rest 78.75 feet past the stop sign, while Hilton and her Cadillac were 6.60 feet past the stop sign. Skid marks at the scene indicate that both drivers applied their brakes at impact until stopping.

 

The speed limit on this section of Hollywood Boulevard is 30 mph to allow safe travel for sight-seers and pedestrians. Was Paris really going more than 10 miles per hour over the posted limit? It is up to a team of contracted experts (that’s you guys!) to decide.

 

By picking situations with cars of various weights, my students have been comparing accident results.  What happens when a sports car hits an SUV?  What happens when two vehicles of a similar weight class are involved?  Why are the cops asking physics students to make such harsh decisions?

After the shock of having to do their own research wore off, good times were had.

Post-Thanksgiving Update

I feel kind of guilty because lots of stuff has happened in the past few weeks, and I’ve shared none of it.

I added my newest set of foldables to the master list.  My intro class is in the section on solving linear equations, and I’m going to try to be better about sharing my notes for the rest of the year.  I have to admit that I was pretty lazy about making foldables the past few weeks, mostly because my classroom printer died.  Part of my planning process is printing out rough drafts of my notes and cutting them to make sure that they fit properly in a notebook.  Without a printer, I’ve been sending drafts to the copy room and walking down to pick them up.  It was fine for the first week or so, and then the walking got old, and I got lazy.  The students had quite a few days of traditional notes from last year.  Luckily, the new printer is in the corner of my room just waiting to be installed.  I’m pretty excited!

I’ve been trying new things in Physics.  We did a lab examining the coefficients of friction on different toilet paper brands and various household materials.  I have a pretty limited lab set-up, so we used Pascars with mounted force sensors on a track and tried to pull across the material at a constant velocity.  In a perfect world, I would have presented a more fool-proof method with an inclined plane.  If I’m lucky enough to teach this class again next year (here’s hoping), I would like to have an inclined plane rig set up for demos.  We’re currently talking about work and energy.  The students are requesting an outside lab before Christmas.  It’s pretty cold around here…so we’ll just have to see about that.

I also bought a house!  Well, kind of.  We put an offer in on a house back in August, and three closing dates later, it really looks like December 16th is going to be the day!  It’s an older house from the 1950’s that needs a bit of love.  All of the outlets are two-pronged, so no grounds, and all of the flooring is tile!  When I say tile, I mean old classroom industrial style tile…it’s the weirdest thing.  There is also a bright pink bedroom, and a teal bedroom and all sorts of things that need to be painted.  It’s kind of freeing to get to design my own kitchen and bathroom.  Exciting times for sure!

Let’s have a fun Friday!

This is the Friday before my birthday.  It’s my personal policy to not assign homework on my birthday.  So what did we do?

Intro:  We played 1, 2, 3 Switch from Tom DeRosa.  I’ve played this game with my students every year, and I always get mixed results.  In the past, students have been really confused about how to handle the K, Q, J, and A cards, so I went ahead and printed number cards for each student.  (This also stops them from trying to play other card games…another problem I’ve encountered.)  I have some changes to the cards that I’d like to make…but when I do, I will share them.

This year, the game execution was flawless and everyone knew how to play.  My 1st hour class loved the game, and I could tell that some of them were going to take it home and play it this weekend.  I brought out my camera and took pictures of them happily playing cards.  This weekend I hope to print out some of the pictures and hang them up in my classroom.  4th hour, however, were not fans.  Some of them whined and asked me to magically conjure a worksheet instead.  My paraprofessional and I had a good laugh over their behavior.  After all…how dare we ask them to play a game?

I asked myself if maybe I’d done a better job ‘selling’ the game to 1st hour…but I really think this one comes down to student attitude…because 7th hour liked the game just fine!

Physics:  I bought inexpensive little stomp rockets from Amazon.com.  Whenever I do an activity like this, it’s hard to say whether or not the students will buy-in until we try it.  When the rockets showed up at my place, I used my high-schooler sister as a test subject, and we shot the rockets at my mother’s house.  I had more fun than I thought I would, and I figured that this would be a safe and easy way to play with projectiles in a school setting.  It was about 34 degrees during lab time today and we walked to a park a few blocks away.  I had each student stomp the rocket 3 times, and with the help of their group, they measured the airtime and the horizontal distance traveled.  On Monday, we are going to estimate other properties of the rocket’s flight using algebra.  If this part of the lesson is successful, I will share the lesson here.

I took so many pictures of my two physics classes.  I was trying to capture the actual rocket launch, but I often missed and got a picture of teenagers staring straight up into the sky.  (Which are funny enough to send to the yearbook!)

I still have my usual round of Friday grading to do, but it was a good day!

Let’s Play Taboo!

So Wednesday is an early day…and picture day…and there’s an assembly in there too!

It really doesn’t pay to jump into anything new with physics, so I created a Taboo-style game that should last all year.

They’re all fancy and laminated and I’m super proud!

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When my class plays tomorrow, they will have 1 minute to talk or act in such a way that will cause the team to say the goal word.  My classes are about 15 students each, so we’ll have three teams and half an hour to play.  I went through my whole physics book and ended up with about 200 cards to cover the entirety of the class.  Since we’re only in Chapter 2, my groups will be playing with about 60 cards tomorrow.  I think it will really help to just add in more cards throughout the year.

I’ve included my template at the bottom; here’s how to make one of your own:

Step 1:  Look in your textbook’s glossary.

Step 2:  Make important terms your “Goal Words.”  (You can use pop culture figures too!)

Step 3:  Pick 4 words that you don’t want your students to say during their turn.  (I laughed more than I should have when I decided that they can’t say Bow Tie when talking about Bill Nye…)

Powerpoint File

 

Finished Physics Taboo Game (More than 100 cards!)

Major Discoveries in Physics

 So in Physics, I wanted to have a little bit of down time surrounding the Chapter 1 Test.

Each student was tasked with picking a physicist, and presenting up to three of their greatest achievements.  We added each achievement to an arrow, and printed pictures of all of our physicists.

(The string is supposed to represent the actual timeline…it’s a little goofy, but I went with it)

Then today I had some of my taller seniors hang it in the corner of my classroom.  It finally looks like the two physics classes have a bit of presence in my decor.  LOVE IT!

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At the end of the timeline, there was a bit of extra space.  They pleaded to add Bill Nye at the end (holding squirt guns, no less…).  Let it go on the record that since we labeled Bill Nye as immortal on our timeline, he is not allowed to die this year.  I’m curious to see if any of my other students or fellow teachers notice and point him out.

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Most of the portraits are from Wikipedia, with the exception of Bill Nye and Stephen Hawking.

(We really wanted to find a younger picture of Hawking to go next to his earlier work.)

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The only physicist that is officially missing a picture is Dimitry Zubarev.  We can’t find one on wikipedia, and we don’t know that anyone painted a portrait either.  We joked about whether or not my student had created the Dimitry Zubarev wiki page to get out of doing research, but it’s really amazing that we managed to find decent pictures of the other 30+ physicists.

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And there’s my new poster!  Some day soon I hope to bring in my real camera and get pictures of my classroom to share.

Halfway there?

So today marks the halfway point of my summer semester in Grad School.  I’m thinking maybe 10 credits was a little much, and that maybe, just maybe math teachers will lapse into group insanity when confined to a classroom for roughly 9 hours a day, 4 days a week.

I should have known better, but I’ve always been ambitious.  My husband accuses me of complaining about not having free time, even though I immediately find more things to fill any free time that I DO have.  So here I am, trying to draft my thesis proposal.  Yes, they told me to wait until my second year.  No, I did not listen.

I’m not quite sure if my topic is going to stick, so I will wait until then to reveal my research topic here.  However, I did learn that this research isn’t quite as bad as I thought.  I looked over examples that had thirty to fifty articles in their literature review, while academic search engines yielded seven or eight valid articles, max.  I panicked!  How was I going to find that many articles?

Without knowing what to do, fearing a dry thesis, (but with a draft deadline approaching) I started to write.  And I realized that many of my articles had citations of their own…research that I could also find and use!  To a seasoned researcher (or English teacher) this might seem like common sense, but in my sleep-deprived grad-school state I felt as though I’d discovered something grand!  Strangely enough, academic search engines are very good when you know which authors or titles you seek.  Go figure!

Dorm life is a unique experience for me.  I lived off-campus in an apartment during my undergraduate degree, so I’ve never had to share so much time with classmates.  Luckily my suite-mate and I get along well, and are in most of the same classes.  I do know some of my classmates, because I’m not the only teacher from my school in this program, so that’s nice.

As I get closer to the new school year, being away from home has gotten harder.  For example, this week I’ve learned that I get to teach a class that I’ve always wanted to teach!  This particular class looks to be a little more cross-curricular than my usual fare, so it will be quite different.  This class also requires changes to my classroom layout, because it has different space requirements than my previous algebra classes.  I can’t wait to get home and tear through the textbook and start planning!

Life is busy, but life is good.