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Freefalling For You: Improve Your Teaching of Freefall!

Chris Meyer, York Mills C.I., Toronto District School Board

Pride comes before the freefall
What topic could be easier, right? It’s just straight up and down — no funny business. Freefall is the poster child of constant acceleration, everyone’s go-to example. We can teach this in our sleep! But we might not realize that we are setting up our students for a physics ambush. While our students’ first freefall problem might seem straightforward and understandable, the second one often contains a trap!

Second freefall problem: “You drop a ball from a window 1.9 m above the ground. How much time does it take to hit the ground?” The student sizes up the problem; it seems easy. The displacement is 1.9 m downward. The acceleration is known; the student is feeling confident. They can find the time if they know one more motion quantity. Ah, the final velocity is zero! Problem solved!

And thus, the unsuspecting student is ensnared in the most common trap of freefall motion. This highlights the real challenge of understanding freefall: students need a genuinely sophisticated understanding of forces to make use of freefall ideas. Emphasizing freefall before studying forces allows students to tumble into numerous, all-too-common learning traps. Let’s nimbly dodge these traps and explore a better way to study freefall! Read More...

Science Communication Presentations from the University of Guelph

Orbax, Production Specialist for Physics Education Content, Department of Physics, University of Guelph

Greetings educators! Orbax here from the Department of Physics at the University of Guelph.

When I went to university for physics in the late 90s, “science communication” as we know it now did not exist. Our science communicators were there, but it seemed like it was much more of a journey to find them then than it is now. Television (both high-end productions and cable access), radio, print media… these were the ways in which we found science communication mostly born out of a necessity to demystify some of the more obscure elements of our profession as well as a way to combat some of the pseudoscience that was rampant in the media. Read More...

Improving the Teaching of Forces: Cognitive Chunking and Chaining

Chris Meyer, Past President, Ontario Association of Physics Teachers

In my early years of teaching physics, I was often surprised by the difficulties my grade 12 students (actually OAC students at the time!) had with forces. Many times, the sneaky culprit responsible for their troubles was the first law of motion. “Why are they having trouble with such simple grade 11 ideas?” I puzzled, “these are good students”. I have been wrestling with this question for 23 years and now have a better understanding of what I'm trying to accomplish as a teacher and what is happening inside my students’ heads. Let’s explore a better way to train students to think about forces. Read More...

This Is Why…

Joanne O’Meara, Professor, Department of Physics, University of Guelph

When people think about what physicists do, they often jump directly to the esoteric, like quarks or globular clusters, and don’t necessarily see the myriad connections of physics to our everyday experiences. I’m not criticizing those among us devoted to the esoteric, but I do worry that we are missing out on inspiring and engaging with a large fraction of the science-curious by not taking the time to explore some of the fascinating physics on display in the natural world. As physicists, we are practiced at the art of asking ourselves Why? when we observe something beautiful, unusual, or unexpected, and the feeling that comes from figuring out the answer is what keeps us exploring. I love being able to bring these little explorations into my classroom, especially when I’m teaching first-year physics to biological science students, as helping them to see the relevance of what they are learning can have a profound effect on their motivation. From the beauty of a double rainbow, to penguins using bubbles to reduce drag, or the effect of polarization of scattered light on flies looking for someone/thing to bite, I love that look of wonder and appreciation on my students’ faces when we take a short tangent to extend our learning in optics or mechanics. Read More...

A New Look at Newton’s Laws of Motion

Roberta Tevlin, OAPT Newsletter Editor, Teacher at Danforth CTI

One of the standard parts of an introductory physics course is a study of Newton’s Three Laws of Motion. They are part of the Ontario curriculum for grade 11 physics and most teachers would agree that they are essential. Chris Meyer has presented an improved way to teach the three laws of motion that will deepen student understanding: Teaching Forces I and Teaching Forces II.

In this article, I hope to reinforce Chris’ approach with a look at how the history of these three laws is wrongly presented. Read More...

Quick Guide for Teaching Physics: Forces

Chris Meyer
President, Ontario Association of Physics Teachers
Hybrid Teacher-Coach for Science, Toronto District School Board

Welcome to part three of my “Quick Guide” series! We have dealt with the introduction to our physics course and the motion unit, which means it is time to tackle the topic of forces. There are many tips and tricks I have come across in physics education research and from refining my own practice that I would like to share with you, so read on! My challenge for you is to choose at least one tip from the list below to try out this year during your unit on forces. Read More...

Controlled Experiments with Three Factors in SPH4C Grade 12 College Physics

Tim McCarthy, Teacher, St. Ignatius of Loyola Catholic Secondary School

Controlled experiments with three factors are a great way for physics students to practice identifying and testing factors that may affect a situation. They provide an excellent opportunity to practice the Scientific Investigation Skills found in Strand A. The students are provided with a situation, brainstorm possible factors that may affect the situation, reduce the list of factors to three that can be tested in the physics lab, develop hypotheses, design procedures to test the factors, test the factors, analyze the data, perform experimental error analysis, and draw conclusions on the effects the three factors have had on the original situation.

My struggle has been to find situations that easily fit this format and that also match the curriculum specific expectations. I have created one three-factor controlled experiment for each of the six units in my 12C physics course. The three-factor experiment in the first unit is used as assessment for learning (formative) to teach the students how to do a controlled experiment. The remaining five experiments are used as assessment of learning (summative). Simulations are used for some experiments as I do not have the necessary equipment to perform all them in the lab. Read More...

The Intersection of Science and Small Contractor House Construction

Dave Gervais, Chair STAO Safety Committee, construction worker

The options for your students that drop out of high school or graduate with high school are very limited. After rolling through the low paying jobs of the service sector, restaurant or retail business, construction work looks pretty good. How do the science and mathematical principles and calculations in construction compare to that taught in our science classes? Read More...

Simplifying Instructions to Unleash the Power of Memory

by Tim Langford

Last month I attended a “train the trainer” workshop for TWI: Training Within Industry. Industry is a different world than education. However, as I took in the information that our instructor offered, my mind naturally gravitated to how these lessons apply to what I know best, the teaching of physics. This is a short article that attempts to link one best practice from industry to what you and I do daily in the physics classroom. Read More...

Rockets: A Beginners Guide Part 3

John Berrigan, Teacher Oakville Trafalger H.S.

In the previous article we found the main factors that determine the thrust of a rocket engine. We rearranged the formula and determined the Impulse of the formula for rockets.EQN1 With Elon Musk discussing his Mars rocket last week, http://www.spacex.com/mars, now is a good time to discuss how Impulse can be used to eventually determine the efficiency of a rocket engine. Read More...

Rockets: A Beginners Guide Part 2

John Berrigan, Teacher Oakville Trafalger H.S.

In the previous article we learnt how to find the largest possible delta-V that a rocket can experience. In this article, we are going to find the thrust of a rocket by using the fundamentals of conservation of momentum. This will be similar to what we did in the last article, however this time we will use variables instead specific masses and velocities. Furthermore, the cart is now a rocket, as this is rocket science! Read More...

Physics On Ice: A Field Trip on Force and Motion

Margaret Scora, Teacher at M. Paul Dwyer CHS, Oshawa ON

Taking a class to Wonderland™ to investigate force and motion can be an expensive and frustrating adventure. The local ice rink is probably only 15 minutes away for most of us, a lot cheaper, and you can be there and back in less than three hours with a whole lot of new experiences for your students to ponder and discuss. Read More...

How to use the OAPT Physics Contest

Roberta Tevlin, OAPT Newsletter Editor, Physics Teacher Danforth CTI

Recently, a teacher asked me for advice about how to start running the OAPT physics contest. I asked some teachers to help me answer this question. As well as finding great advice for getting students to write the contest, I also learnt about other contests and how teachers were incorporating past OAPT contest questions into their course all year long. Read More...

System and Free Body Diagrams

Eric Haller, Physics Teacher, Bond Schools International

When asked to draw a force diagram for some simple situation, most students emerging from any level of introductory physics course are likely to draw objects which look like a porcupine shot by an Indian hunting party—the number and direction of pointed entities being essentially stochastic.

Arnold Arons (1979)

My name is Eric Haller. I’m a new teacher and I am currently at the start of my third year teaching in China. Even though I live so far away, I was able to make it to the physics camp in Sudbury two summers ago. There I got a book called FIVE EASY LESSONS: Strategies for Successful Physics Teaching by Randall D. Knight, which I highly recommend. In this book, Knight talks about many different ways we can improve how we teach physics, a few of which I’ve actually tried out with my students. I want to share with you one of the successes I’ve had with those strategies, here is how I teach my students to draw system and free body diagrams.


Barges: STEM Competitions for grades 9 to 12

Roberta Tevlin, Danforth Collegiate, Past President of OAPT

Competitions are a great way to motivate students, to provide a rich learning experience and incorporate the STEM disciplines and problem-solving approach. Unfortunately, it can be hard to find competitions that are appropriate. They need to be challenging but not impossible. They must use cheap materials and tools and should not require significant building skills. If possible, they should require precision in measurement and calculations. One competition that does all of these; and not only that, it has curriculum connections ranging from grade 9 Science to grade 12 Calculus, is “Barges”. Read More...

Bernoulli’s Principle

Martin Williams, Department of Physics, University of Guelph

In this demonstration, we utilize simple everyday household items to test Bernoulli’s principle and verify the apparent counterintuitive nature of its predictions. Read More...

An Ultimate Elevator Ride: Weight and Apparent Weight Demonstration

Marina Milner-Bolotin, Department of Physics, Ryerson University

We all know that some concepts are harder for students to comprehend than others. The concepts of weight, apparent weight and weightlessness are often stumbling blocks for many of our students. Apparently they are also somewhat confusing for the seasoned scientists and engineers. While visiting the Lyndon B. Johnson NASA Space Centre in Houston, TX, I had a unique opportunity to have lunch at the “Zero-G Diner”1. Apparently, the Space Centre Houston is located at a special place where Newton’s Law of Universal Gravitation does not hold and should be modified. Read More...

Simple Centre of Mass Demonstrations

Tetyana Antimirova, Ryerson University

There are several very simple demonstrations on centre of mass that can be performed with everyday objects. In this article I describe a couple of demonstrations that I do with my students. Read More...

Water Rockets

Rolly Meisel

Having students construct and launch a water rocket is an entertaining way to investigate Newton's Third Law of motion. Students can construct the rockets at home for an in-class launching session. Read More...

Demonstration of a Variable Tension in a Pendulum’s String

Marina Milner-Bolotin, Department of Physics and Astronomy University of British Columbia, Vancouver

A very effective demonstration of a variable tension in a swinging pendulum can be performed using very simple equipment. Read More...

The Belt-Hanger

Ernie McFarland University of Guelph

This article first appeared in the OAPT Newsletter in 1987. It is being repeated here for three reasons: the demonstration is a classic, 1987 was a long time ago, and now this demo (and others) can be seen online (use the link at the end of the article).

One category of good physics demonstrations involves the “disorientation” or “disequilibrium” of students. The demonstrations in this category cannot be explained by most students, and thus serve to disorient the students into a state of disequilibrium from which they wish desperately to escape. Read More...

Buoyancy and Newton’s Third Law of Motion

Ernie McFarland University of Guelph

This article is excerpted from Physics in Canada, Volume 61, No. 2, (2005), pg. 87-89, with permission of the Canadian Association of Physicists (CAP).

In recent years the active engagement of students in physics classes has become increasingly common, especially with the publication of Eric Mazur’s book “Peer Instruction” (Prentice Hall, 1997). A frequently used format is to pose a multiple-choice question, and ask the students to discuss the question in small groups and vote on the possible answers by a show of hands or computerized remote-control technology (“clickers”). This basic approach can be used with a question about the possible outcomes of a lecture demonstration. The instructor shows the demonstration apparatus and states what will be done with it, but does not perform the demonstration nor indicate what the result will be. Students discuss the possible outcomes and vote on them, and then the demonstration is completed to show what actually happens, and the relevant physics is discussed. Read More...

Mystery of a Pulled Spool

Tetyana Antimirova, Department of Physics, Ryerson University

One of the ubiquitous simple physics demos that works equally well for all audiences from small children to the students in the introductory mechanics course is a plastic or wooden spool (or yo-yo) with a string wound around it. A virtually no-cost version of the “demo equipment” is a spool of common household sewing thread. Being curious, I did a Google search on yo-yo, and the search produced about 120,000,000 results! Read More...

Balancing on the Edge and Inexpensive Accelerometers

Diana Hall, Bell High School, Nepean

Diana Hall presents two simple demonstrations.

Ball and Ramp Races

John Childs, Grenville Christian College, Brockville

This is a good exercise to use after you’ve done kinematics, dynamics, and energy. We all talk about the kinetic and potential energy of roller coasters and their speeds, and the demonstration will let your students apply their critical thinking skills to this kind of situation. Be sure to have your students examine the setup and predict the outcome, before you run the demo. The question is: “Which ball gets to the end of the ramp first?” Read More...

The Sailboat Problem

Eknath V. Marathe, Consultant, STS Education

The sailboat provides one of the most interesting illustrations of vector resolution. Read More...

The Prisoner

John Childs, Grenville Christian College, Brockville

This is an exciting force vector demonstration, which is guaranteed to create some pandemonium in your classroom! It can be done just as a visual demonstration, or as the introduction to a stimulating and challenging problem to get everyone in the class working. Your better grade-12 students can pursue the solution to a considerable length. Read More...

Flying Time

Dave Erb, Red Lake District High School

This is a demonstration of centrifugal force.

Huge Pendulum, Centre of Mass, and Magnetic Force

John Earnshaw, Trent University

The author presents three demonstrations: a large pendulum, the centre of mass of a person, and the magnetic force on a beam of electrons. Read More...

Falling Faster Than ‘g’

T. Dean Gaily, University of Western Ontario

A simple lecture demonstration to illustrate that some objects do ‘fall’ with an acceleration greater than 9.8 m/s2 is constructed from two pieces of 2.5 cm × 15 cm lumber approximately 1 m in length (1” × 6” × 39”), hinged together at one end. A small marble placed in a notch at or near the end of the “falling” board can be made to fall slower than the board and land in the cup strategically placed on the falling board. Read More...
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