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.


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


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]

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


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".