Wednesday, May 11, 2022

New Electromagnetism Lessons Added

Right hand rules in high school physics do not bring me great joy. I cringed when The Physics Teacher ran a photoessay from an instructor who photographed students contorting hands during an exam. (A cursory search for this article was unsuccessful. I hope it was expunged.) 

Nevertheless, 3-D geometry cannot be avoided when studying magnetic fields and forces. In the ├śrsted's discovery lab, students develop a right hand rule relating to current and the magnetic field it produces. That was Right Hand Rule #1.

This activity relates current, external magnetic field, and magnetic force. Right Hand Rule #2.

Just an exercise in exercising the right hand rule of your preference. After a few simple scenarios, things get a bit more interesting and the last one is quite open-ended.

We move from the Lorentz force to a derivation of V = BLv step by step. Tangential, peripheral references to an ancient Monty Python sketch can be found, but need not be appreciated.







Sometimes textbooks jump into flux a bit hastily. So I produced this lesson to build the concept by analogy to wind blowing through a window. "Air flux" is more intuitive, and offers a path toward understanding magnetic flux.

Once flux is on board, developing Faraday's Law of Electromagnetic Induction can be attempted. The derivation is taken one step at a time, but we eventually get there. The core of Faraday's law is that the voltage induced in a loop is the rate at which flux changes. The "–" and the "N" in the equation serve a purpose, but are not central to the application of Faraday's law.

All of these have been added to A Bundle of Phyz: ELECTROMAGNETISM.

Saturday, May 7, 2022

Picture a Scientist


I thought this needed a question set, so I wrote one. It's now the featured free resource at The Lessons of Phyz store on Teachers Pay Teachers.

Thursday, May 5, 2022

The Secrets of Quantum Physics

Professor of physics Jim Al-Khalili investigates the most accurate and yet perplexing scientific theory ever - quantum physics. The program's two episodes
stream on Amazon Prime. YouTube links have also been embedded in the text below and the titles in the student documents.

The history of and battle over quantum entanglement. Albert Einstein hated the idea that nature, at its most fundamental level, is governed by chance. Professor Jim Al-Khalili reveals how, in the 1930s, Einstein thought he'd found a fatal flaw in quantum physics because it implies that subatomic particles can communicate faster than light in defiance of the theory of relativity. Delightful bonus: "Tangled Up With You" by Eliza's Uncertainty, a perfect addition to your modern physics playlist.

Friday, April 29, 2022

Switch Wars [Design Lab]

Design Challenge:
Using only a battery, bulb, wires, and two single pole double throw switches, make a “three-way” switch. A three-way switch involves 2 two-position switches (like common light switches in houses). Either switch can be used to turn a light on or off. Such two-switch systems are often used for lights in stairways, long hallways, or for outdoor structures. Children (of varying ages) sometimes battle each other by stationing themselves at opposite switches; one tries to keep the light on while the other tries to keep it off.


Includes

Student document (print-friendly Google Docs file on Google Drive)

Answer key

Wednesday, April 27, 2022

Logic Gates [Lab + Job]

When I began the patient siege of outfitting my lab at Rio Americano High School (c. 1990), I leveled up on batteries (C- and D-cells), bulbs (various incandescent flashlight "mini bulbs"), connecting wires (alligator clip "jumpers") and switches (single throw, single and double pole ceramic and copper). 

My wish/shopping list came from Paul Robinson's Conceptual Physics: A High School Program by Paul Hewitt 1/e Lab Manual. I had tagged each lab I hoped to do, then assembled a spreadsheet list of the apparatus I would need.

And as was the case with my mechanics apparatus and materials, I began developing other labs for my students to conduct with those materials.

Tuesday, April 26, 2022

A Bundle of Phyz: MIRRORS AND LENSES

Much can be made of spherical mirrors and thin lenses in the geometric optics curriculum. Here are a few.

Is the image upright or inverted? Enlarged or reduced? In "Image Characterization," students are tasked with such determinations.

In "Mirror Experience," students gaze upon their reflections in a hand-held spherical mirror at various distances and characterize their own images.

"Ray Tracing 1 and 2" are exercises in drawing principal rays to construct images in spherical mirrors.

Monday, April 25, 2022

The Fringe of Optics [PhET]

Use
PhET's Wave Interference sim to construct the mathematical relation describing interference patterns

The modern study of light began in the late 1600s and early 1700s with Isaac Newton in England and Christiaan Huygens in the Netherlands. Newton theorized that light consisted of particles. Huygens theorized that light consisted of waves. In 1801, Thomas Young offered convincing evidence for the wave model of light when he demonstrated that light could produce an interference pattern. 

Sunday, April 17, 2022

A Bundle of Phyz: HARMONIC MOTION

The bundle opens with a PhET-fueled exploration of Hooke's law. "Spring to Another World" utilizes the
Masses and Springs simulation.

Then its on to a guided classroom discussion on elastic potential energy which works through a side-by-side compare and contrast with gravitational potential energy. Practice the equation developed in the springboard on a few toy gun number puzzles.

"Springs and Swings" provides a PhET-fueled introduction to simple harmonic motion, while also delving gently into Google Sheets and linearization. This one leverages Masses and Springs: Basics and Pendulum Lab.

Wednesday, April 13, 2022

A Bundle of Phyz: FLUIDS

When the College Board added fluids to the AP Physics B exam, I felt like I needed to create a new unit from whole cloth. This bundle includes most of what I subsequently produced over the years.

We begin with pressure and its idiosyncrasies, addressed in a springboard (guided classroom discussion) and a job (independent homework). Next we dive into PhET's Density pool in our first sink-or-float lab activity, "Pool Cubes 1 - Density."

Conceptual Physics Alive's telling of fluids begins with "Liquids I," in which he demonstrates principles using Pascal's vases, among other things.

Thursday, April 7, 2022

A Bundle of Phyz: ROTATION

The bundle opens with a guided classroom discussion on "A New Kind of Motion": rotation. It's fundamentally different from linear motion.

"A Question of Balance" is a PhET-fueled lab activity that sets and applies the conditions for balance using the Balancing Act sim. It's a nice precursor to an in-class, hands-on balanced torques lab.

"Torque" is a guided classroom discussion that builds toward an equation for torque by examining various factors one at a time.

A Bundle of Phyz: HEAT + THERMO

The bundle opens with a virtual demonstration of thermoscopes and a discussion of temperature scales. Next we have the classic ball and ring thermal expansion demonstration guide, followed by a demonstration to see the difference between hot and cold in a couple of ways.

The Mechanical Universe's "Temperature and the Gas Laws" is up next, followed by Conceptual Physics Alive's "Heat, Temperature, and Expansion".

Saturday, March 26, 2022

Connect the Dots [Lab]

In this activity, students build a simple wave machine and observe wave propagation, reflection, and the factors that determine wave speed. This activity takes a bit of unusual prep work, and some parameters cannot be quantitatively controlled. But it's the only lab that students routinely captured photos and videos to post to their social media accounts.

I posted a "how-to" construction video to YouTube: Connecting the Dots.

Wednesday, March 23, 2022

A Bundle of Phyz: ENERGY

This busy bundle opens with springboards introducing gravitational potential energy and kinetic energy.
The Mechanical Universe's episode on "Potential Energy" includes a nice historical perspective via Roger Boscovich. Ranking tasks for potential energy and kinetic energy close out the mechanical energy introductions.

Next up is an exercise in tracking energy transformations. In the Before Times, students drew their own sketches. In remote teaching/distance learning (RT;DL) that became impractical. In class, I followed this lesson with a showing of the classic Honda Cog ad. Two minutes of energy transformations, with some nice unstable equilibrium configurations, to boot. No CGI, and it only required a bit more than 600 attempts to nail it. OK Go's "This Too Shall Pass" video presents even more shining examples.

Physics in the Fountain of Fizz [Virtual Demonstration]

The Diet Coke Mentos geyser seems to have erupted onto the popular culture scene around 2006. Many analyses of the geysers focused on the "chemistry" of the eruptions: the interaction between the candy's shell and the soda.

To be a bit different, I created this activity to focus on the physics of the eruptions. When remote teaching/distance learning (RT;DL) came along, I was determined to keep this demo alive.

Wednesday, March 16, 2022

A Bundle of Phyz: MOMENTUM

The bundle opens with the springboard (guided classroom discussion with presentation) that introduces momentum.

Next we have the "Take a Flying Leap" springboard, an exploration of impulse that ends with me jumping off the historic Victoria Falls Bridge between Zambia and Zimbabwe.

The Kinetic Karnival of Jearl Walker then takes us through stories and demonstrations of "Forces & Collisions". Jearl chops through concrete bricks with his bare hands and survives a cinder block being smashed on his chest while sandwiched between two beds of nails.

Kinetic Karnival - Episode 1: Forces & Collisions

Before Jearl Walker became the current author of the famed Fundamentals of
Physics by Halliday, Resnick, and Walker, he was a pioneering popularizer of physics, even appearing on The Tonight Show with Johnny Carson. He authored "The Amateur Scientist" for Scientific American and the classic, The Flying Circus of Physics — With Answers. [The Flying Circus of Physics (without answers) was published and can probably be found by skilled book hunters.

I was a fan of Walker and his work when I walked into my classroom for the first time. So when I saw that The Kinetic Karnival of Jearl Walker, filmed, produced, and broadcast just a few years prior was available for purchase, I directed my school budget to do so.

Tuesday, March 15, 2022

Things That Go "Bump" [Virtual Demonstration]

Is there more force when objects collide and stick to one another or when objects collide and bounce off each other?

This classic demonstration shows an important difference between elastic and inelastic collisions using "happy" and "sad" balls.

During remote teaching/distance learning (RT;DL), I produced this version of the demonstration. The instructional presentation link is included in the answer key; it's best if the instructor guides students through this. For Zoom presentations, Instant Reaction polls are included.
Includes
Student document (print-friendly Google Docs file on Google Drive)
Instructional presentation with observation videoclips (link embedded in answer key)
Answer key