Saturday, February 16, 2019

The Lessons of Phyz — 2019

The Lessons of Phyz store at Teachers Pay Teachers is now one year old and features even more items than it did last time I posted about it. I know, right? It began with question sets for the classic, Mechanical Universe: High School Adaptation—a video series that you can neither buy nor stream in 2019. Since then, I've added video question sets to more than cover your next jury duty needs. Here are all the delicious digital documents on offer as of February, 2019.

Cosmos: A Personal Journey by Carl Sagan [1980]. Question sets for all 13 episodes: The Shores of the Cosmic Ocean, One Voice in the Cosmic Fugue, Harmony of the Worlds, Heaven and Hell, Blues for a Red Planet, Travellers' Tales, The Backbone of Night, Journeys in Space and Time, The Lives of the Stars, The Edge of Forever, The Persistence of Memory, Encyclopaedia Galactica, Who Speaks for Earth?

Cosmos: A Spacetime Odyssey hosted by Neil deGrasse Tyson [2014]. Question sets for all 13 episodes: Standing Up in the Milky Way, Some of the Things That Molecules Do, When Knowledge Conquered Fear, A Sky Full of Ghosts, Hiding in the Light, Deeper Deeper Deeper Still, The Clean Room, Sisters of the Sun, Hidden Worlds of Planet Earth, The Electric Boy, The Immortals, The World Set Free, Unafriad of the Dark. 

How Earth Made Us | How the Earth Changed History by Professor Iain Stewart. Question sets for all five episodes: Deep Earth | Beneath the Crust, Water | Water World, Wind | The Skies Above, Fire | The Gift of Fire, Human Planet | The Human Era.

Physics: Electricity and Magnetism. Question sets for documentary program episodes, Lightning!, Search for the Super Battery, Magnetic Storm, Aurora - Fire in the Sky.

Physics: Modern Physics. Question sets for feature-length documentary films, Einstein's Big Idea and Atomic Café.

The Singles Series
Single-item question sets. Some are included in modules elsewhere in The Lessons of Phyz.
Merchants of Doubt
Before the Flood
Secrets of the Psychics

The Mechanical Universe: High School Adaptation
Mechanical Universe 1: Motion and Forces
The Law of Falling Bodies, The Law of Inertia, Newton’s Laws, Moving in Circles

Mechanical Universe 2: Gravity
Kepler’s Laws, The Apple and The Moon, Navigating in Space, Curved Space and Black Holes

Mechanical Universe 3: Conservation
Conservation of Energy, Conservation of Momentum, Angular Momentum

Mechanical Universe 4: Temperature, Vibrations, and Waves
Temperature and the Gas Laws, Harmonic Motion, Introduction to Waves

Mechanical Universe 5: Electrostatics
Electric Fields and Forces, Equipotentials and Fields, Potential Difference and Capacitance, The Millikan Experiment

Mechanical Universe 6: Circuits And Magnetism
Simple DC Circuits, Magnetic Fields, Electromagnetic Induction, Alternating Current 

Mechanical Universe 7: Light And The Atom
Wave Nature of Light, Models of the Atom, Wave-Particle Duality

The Earth Science Series
Earth Science 1: Science, Mapping, and Water
Secret of the Psychics, Lost at Sea: The Search for Longitude, Water, Earth Under Water

Earth Science 2: Atmosphere and Weather
Our Atmosphere, Predicting Weather, Wind

Earth Science 3: Climate Change and Human Impact
Megastorm Aftermath, Before the Flood, Human Planet

Earth Science 4: Tectonics, Volcanoes, and Earthquakes
Colliding Continents, Deep Earth, Deadliest Volcanoes, Deadliest Earthquakes

Earth Science 5: Astronomy in the Solar System
Meteor Strike, Life Beyond Earth: 1. Are We Alone?, 2. Moons & Beyond, Secrets of the Sun

Earth Science 6: Astronomy Beyond the Solar System
Life & Death of a Star, Invisible Universe Revealed, Alien Planets Revealed, Alien Galaxies

Question sets covering Paul Hewitt's Conceptual Physics Alive! video series are available from Arbor Scientific in two ways: The Complete Edition (hard copies and PDFs on DVD) and Disk Edition (PDFs on DVD).

Monday, February 11, 2019

The Inverse Leidenfrost Effect at Veritasium

Here at The Blog of Phyz, we're big fans of the Leidenfrost effect. If you search "Leidenfrost" here, you'll see exactly how much we love it. I blame Jearl Walker.

As always, Veritasium's Derek Muller gets us.

Inverse Leidenfrost? What can that possibly be about? Take a look:

The Inverse Leidenfrost Effect

Sunday, February 10, 2019

Physics Fun on Localish

Ray Hall is a California physics professor and a skeptic friend from way back. So yes, he is made of win.

He has also crafted arguably the best account on Instagram: physicsfun. And by "arguably" I mean that you and I might have an argument if you think there's a better Instagram account out there.

As a delightful bonus, physicsfun passed the million follower mark months ago: a reason to be hopeful for the future.

If you don't have an account on Instagram, physicsfun is a reason to get one.

Folks are taking note. ABC's Localish produced a nice segment on Ray and his Instagram.

S1E31 Crazy for Physics on Instagram 

Instagram: physicsfun

Saturday, February 09, 2019

Wednesday, February 06, 2019

Which way is north? Not so fast...

It isn't where we left it.

Over the course of geologic time, magnetic north wanders like the oft-maligned "drunken sailor". And it reverses polarity on a not-entirely-stochastic basis. It seems the pole is on the move again—with faster than normal speed—and models will need to be updated to keep pace.

As Magnetic North Pole Zooms Toward Siberia, Scientists Update World Magnetic Model

The North Magnetic Pole Is Shifting East, Fast

Even in the era of GPS, Earth's magnetic field is still an important component in terrestrial navigation.

Sunday, February 03, 2019

Torque-Master Challenge 2019

After completing the "Torque Feeler" / "It's All in the Wrist" Conceptual Physics Lab Manual activity, we add the Torque-Master Challenge.

We again repurpose our five-foot aluminum tube from the Pasco Scientific Lenz's Law Demonstration set. Sometimes we use it as a blow gun. Sometimes we use it for examples of resonance. This time, we tie an ordinary 500-mL water bottle to the end. Challengers must hold the arrangement level for ten seconds.

Over the years, I have found that very few of my students can do this. I can, and I am not young, cut, ripped, or chiseled. And I do not lift. I mean, look at me in the video. Honestly!

Torque-Master Challenge 2019

Why I can do this while so few of my students can is a mystery I have no answer to. Now that I think of it, though, very few of them can match my speed when we use this tube as a blow gun. I have no explanation.

When we find students cannot match my blow gun speed, I admonish all of them to quit smoking!

Sunday, January 27, 2019

Torsional pendulum

This was another one of those things I wrote on my "To Do" list and figured I should complete before it had been on there a year.

On the day my AP Physics C students learn about torsional (twisting) pendulums I had written myself a note that while they "got it" they were having problems visualizing it. I didn't know how to construct one so I started an internet search and found a lot of problems about them but not a lot of demos. I found one video that looked promising and took a still to help guide my trip to the hardware store. The description called it a chuck nut which didn't seem quite right. After asking for help on Twitter I got a response:

He was nice enough to offer some advice and a link to the part he used. Once I knew what the part was actually called it was much easier to find them. When looking for the right pinch vise I looked for ones sold individually (most are in sets) and checked the range that it could hold. Many can securely hold amazingly small pieces so you have to also check out the max that they can hold. I settled on these, fairly cheap and should be versatile.

When I got them I was able to set up a few different demos. I drilled a hole into a golf ball the size of the end of one of the pin vises and wedged it in. I didn't want to glue it in yet because I didn't know what else I wanted to make. I cut lengths of fishing line, nichrome wire and a steel wire about the same length. I added a red and blue line on the golfball 90 degrees apart so it would be easier to see how much it was twisting. One end of each wire could be put into one of the two pinch vises, the one without the golfball hanging from a ring stand clamp.

I showed students the golfball oscillating with the fishing line, nichrome and steel wire in class. A video of each is below. We did not calculate anything (the wires were really bent) but it worked as a qualitative experiment. 

Afterwards I tried making some more with different masses, a small brass mass and a large rubber stopper. The tricky part is attaching the steel cable so that it doesn't twist within the object. I added hot glue to the brass mass but its not as secure as I would like. I added a black line in sharpie to the mass so the oscillation was easier to see. For the rubber stopper I was able to stab the cable through the stopper, although drilling a hole may have been more precise. I added a white pushpin to the side so that we could see the oscillation better. For these last two versions I only needed one pinch vise at the top to hold the cable. 

All in all I really liked the way it turned out and it helped students to visualize what was happening with their problems. It can always be improved but at least I have another year until I need it again. 

Friday, January 25, 2019

Spring demo set-up

I joke with my classes that the last class of the day gets the best version of me. At least today it only took one period for me to get this worked out.

My AP Physics C are studying simple harmonic motion and the most common type is a block attached to a spring on a horizontal friction less surface. Surprisingly our book does not touch upon springs in series and parallel. Students did a quick activity using PhET's Hooke's Law simulation the other day, leading them to the equations to find the equivalent spring constant if series and parallel pendulums. We ran out of time that day to show it to them live so I set it up for the next day.

I had two identical springs of spring constant 20 N/m +10% that I hung from a horizontal support attached to two large ring stands. I used a pegboard hook to link the two springs when working in parallel which made it easier to hang one mass from it. For the first class of the day I hung a 500 gram mass from a single spring, then the two springs in series and then in parallel so the class could see the difference. The series elongation was very easy to see the difference but the parallel elongation was harder for those in the back. So I added to it between classes.

I used bright post-its and labeled the natural length of one spring, where it stretched to in parallel and in series. I taped a measuring tape in line with the top of the spring so if I wanted to, I could do calculations. It made for a much better visual for the students.

After the fact I realized I wanted to add a marker for the natural length for the two in series since the new length is much larger than twice the stretch of the single spring because of the additional length of the second spring. If I had enough springs of the same spring constant I would want to have all three setups up at the same time. Add that one to the wishlist I guess.

Tuesday, January 22, 2019

The Electricity Playlist of Phyz

Wow. Electricity seems to be very well represented in the world of popular music.

My Blog of Phyz colleague, Dan Burns, has apparently been making music playlists for years. So I'm giving it a go, too. Seems like great fun. With today's seemingly limitless access to music and the magic of search engines, prospects are good that a number of tracks can be identified for any particular topic. The trick is to steer clear of "E" (explicit lyrics songs).

Playlists can be set to shuffle during lab activities in class, if you're inclined to do such. I put out a call on Twitter, and my initial list of 30 sounds more than doubled. Crowd-sourcing!

My Physics classes just worked through a couple of electrostatics labs and several circuits labs are coming up. I fear the music well may run dry when it comes time to assemble a magnetism playlist.

Here is the electricity playlist (as of today):

The Electricity Playlist of Phyz
Are Friends ElectricGary Numan1979
Be Direct With MeGeneral Electric1966
The Body ElectricRush1984
Brighter than the SunColbie Caillat2011
Chain LightningRush1989
Chain LightningSteely Dan1975
City ElectricAnberlin2015
Danger! High VoltageElectric Six2003
Dry LightningBruce Springsteen1995
Electric AvenueEddy Grant1982
Electric BlueThe Cranberiies1996
Electric BlueIcehouse1987
Electric ChapelLady Gaga2011
The Electro Co.U21980
Electric FeelMGMT2007
Electric LoveBØRNS2014
Electrical StormAna Free2013
Electrical StormJoseph Arthur2009
Electrical StormMatt Walters2013
Electrical StormU22002
ElectricityThe Glands2018
ElectricityOrchestral Manoeuvres in the Dark1988
ElectricityElton John2004
Electricity Iration2008
ElectricityJoni Mitchell1972
Electricity (acoustic)Silk City & Dua Lipa2018
Electricity, ElectricityGoodness1996
Greased Lightning"Grease" Original Cast1978
GypsyFleetwood Mac1982
High VoltageAC/DC1975
Hold on TightElectric Ligh Orchestra1981
LightningAlex Goot2012
LightningLittle Mix2015
LightningREO Speedwagon1972
LightningState Champs2018
LightningThe Wanted2012
LightningCash Cash2016
The Lightning StrikeA Silent Film2015
Lightning StrikeSnow Patrol2008
Lightning StrikesAngel Taylor2009
Lightning StrikesDawn and Hawkes2015
Lightning StrikesR52015
Lightning StrikesWinnie2017
Lightning StrikesYes1999
Low Spark of High Heeled BoysTraffic
PureLightning Seeds
She's ElectricOasis1995
ShockPsychedelic Furs1987
Shock Me Into LoveLenka2011
Shock the MonkeyPeter Gabriel1982
Shock to the SystemYes1991
SparkTori Amos1998
SparkAmber Run
SparksJames Bay2015
This is What You Came ForCalvin Harris2016
Thunder and LightningPhil Collins1981

If I missed a gem, let me know in the comments. 

Sunday, January 20, 2019

Physics Problems Get Tested by Drones

A drone is hovering in an elevator. The elevator goes down. What would happen to the drone? Alternatively, the elevator goes up. What happens to the drone now?

Make your prediction and then watch this video.

Of course, this is a sequel to what happens in a car. 

Or the even more famous, problem about truck carrying pigeons on a bridge.

I love when famous physics problems get tested in the real world.