Video-Based Problem-Solving Challenges
Each problem involves making observations from the videos to collect the information required to solve it. Each problem has a solution video so students can compare their predicted results with what actually happens!
Why Are These Problems Effective?
They are rich: They have a bit of a story to them, they involve real objects and students must predict what actually happens.
They model expert thinking: Students must decide what information to collect from their observations, must decide what physics quantity to solve for, and follow a highly-structured solutions process that encourages them to do a lot of physical thinking before they do much mathematical work. All of this models closely the ways experts tackle real, poorly-defined problems.
They are rewarding: Students really enjoy these challenges because they feel meaningful (unlike most textbook problems), require a lot of work, and then get to physically test whether their predictions are correct. The physical test has a powerful motivating effect! Our returning graduates routinely comment on how valuable these experiences were.
Teaching Tips
Training: Students should be trained how to solve these types of problems. Otherwise, they get stuck after a few minutes and give up. Here is our training presentation. Our grade 12s hit the ground running here since we train them throughout grade 11 using most of this solution process.
Structure: The real value of these problems comes from the process students go through while solving. The process needs to be highly structured to reduce counter-productive learning behaviours like randomly cramming numbers into equations to wing a final answer. The structure allows students to explicitly practice aspects of expert-like thinking. Here is our generic solution sheet we use for these challenges.
Time: These types of problems are much more time consuming than regular ones. Part A, the pictorial representation, is especially challenging as they sort out what is happening and decide what information to gather and use. This is the same for experts: they spend a lot of time carefully defining the problem before investing effort in the solution. It is normal for students to take about 40 minutes to complete part A
Student Work: When possible, students should complete their work on paper using pencil. If they can't get a physical copy of a solution sheet, they can use a blank sheet of paper and include all the solution headings, or they can electronically annotate the pdf.
Improvement: There is a lot going on in the solution process and students need lots of feedback to improve. After they have tested their prediction by watching the video, we have our students use a blue pen to make corrections and improvements to their written work using our model solutions. We mark the quality of their original work and how carefully they made their improvements. You can learn more about this process here.
Solutions: This folder is for teachers only and contains the video solutions and the written solutions students use to correct their work. Once you have access, you can share links to those files with your students. We release the links to the solutions near the end of the students' work process.
Variations and Results: In many of our challenges we vary different parameters for each group so they all predict different results. Because of this, students understand that the numerical values they see on the model solution pages are not meant to match their values! In the video versions, there is just one set of parameters so all groups should get similar results.
Word Documents for the problem statements and solution sheets can be found here.
Challenge Links: The headings below for each challenge have links associated with them. You can copy the link and send it to your students. Very little prep!
CGPS - Introduction.pptxSolution Sheet CGPS.docxThe Washer Drop
1-D Motion, Freefall
Position five washers along a string so they strike the ground making a steady sequence of "clinks"!
Variation: each group can have a different length string.
Deadpool Drops In!
1-D Motion, Two Objects, Freefall
"Deadpool" is a steel ball bearing that is dropped from an electromagnet when a cart with friction passes underneath. Where should the cart be released (and the electromagnet turned off) so Deadpool lands in the centre of the car?
Variation: Each group adds a different "amount of gold" to the car.
The Ramp and Cup Challenge!
Projectile Motion, No Angles
A marble is launched from a horizontal ramp. Find its launch velocity and then predict where to position a target cup so the marble lands in it!
Variation: groups use tables (surfaces) of different heights.
The Car Launch!
Projectile Motion, 2 Intervals, Angles
A toy car is launched from an lincline. Where should you position the target bucket so the car lands inside?
The Scale on an Incline Challenge!
Forces, incline, scale readings
Place a scale on an incline. Put an object on top. Predict the value the scale will read! Sounds simple, but there are subtle and challenging physics ideas at work here.
Variation: Each group chooses their own object.
The Rollercoaster Challenge!
Forces, motion, incline, pulley
We release a "rollercoaster car". It accelerates up an incline due to a falling counterweight. The challenge is to determine the mass to add to the counterweight such that the car reaches the top of the track with a maximum speed of 1 m/s.
Variation: Each group has a different mass on the car.
The Static Friction Incline Challenge!
Friction, incline, no motion
Use measurements made horizontally to predict the angle at which a box on an incline will begin to slide.
**There is no problem statement or solution sheet for this challenge.
The Acceleration on an Incline Challenge!
Friction, incline, acceleration
Use measurements made horizontally to predict the acceleration of a cart on an incline.
**There is no problem statement or solution sheet for this challenge.
The Circular Motion Challenge!
Circular motion, forces
A rotating rubber stopper "holds up" a mystery object. Make measurements of the system and predict the mass of the mystery object.
Variation: each group has a different mystery object.
Thor's Hammer!
Energy and momentum
Thor's "hammer" swings down and collides with "Thanos", sending him flying. Predict the speed that Thanos moves at after the collision.
Variation: the mass of Thanos is different for each group.
The Bungee Jump
Energy
We attach a "person" to a spring and drop them from a great height. Predict the starting position of the person so they get as close to the ground as possible without hitting.
Variation: the mass of the person is different for each group.
The Deflection of an Electron Beam!
Uniform Electric Fields, Force, Energy
An electron beam travels from a gun between a pair of oppositely charged parallel plates. Predict where the beam will strike the plates!
"Variation": a different high voltage for the power supply.