At a Glance

Discipline

  • Physics

Instructional Level

  • College & CEGEP

Course

  • Mechanics 203-NYC-05
  • Waves & Modern Physics 203-NYC-05

Tasks in Workflow

Social Plane(s)

  • Individual
  • Group
  • Whole Class

Type of Tasks

  • Solving problems
  • Reviewing & assessing peers

Technical Details

Useful Technologies

  • Whiteboards, pens, erasers.

Class size

  • Small (20-49)

Time

Single class period (< 90 mins)

Overview

In this activity, students work in teams to solve physics problems. They are to provide complete solutions (e.g. modelling the word problems/diagrams into free body diagrams, vector and/or scalar equations, words) as if they were solving a test question.

Prior to the activity, students have seen/read the necessary material in order to complete this activity. The instructor begins class by explaining what is expected as a “complete solution for a test question.”

The students then form 6-7 groups and are assigned a whiteboard onto which they will present their model. There are enough markers for everyone ...

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In this activity, students work in teams to solve physics problems. They are to provide complete solutions (e.g. modelling the word problems/diagrams into free body diagrams, vector and/or scalar equations, words) as if they were solving a test question.

Prior to the activity, students have seen/read the necessary material in order to complete this activity. The instructor begins class by explaining what is expected as a “complete solution for a test question.”

The students then form 6-7 groups and are assigned a whiteboard onto which they will present their model. There are enough markers for everyone and one eraser per board. Students are encouraged to each have a marker, and to move the desks and tables around the white board (so they can all stand at the board).

The instructor then selects 2-3 problems to be solved (usually from a longer assignment set); each problem must be solved by at least two groups. The problems are displayed on the projector for everyone to see.

Students will need around 15-20 minutes to complete the task. The students are encouraged to look around the room. The instructor usually stands in the middle of the room such that he/she can easily scan all boards. The instructor will assist groups who seek help and ensures that all groups are producing complete solutions. The in-class tutor(s) walk around and help when asked by groups.

The instructor visits groups that finish the task quickly and (if correct) adds a modification to the problem to complexify it, to be solved again, and/or will ask a student to join another group that may need help.

After groups complete the task, each assigned problem must be “show and tell” by one group. After the group does so, other groups that completed the same problem have an opportunity to comment, provide an alternate way of solving, etc. The instructor then approves of the complete solution or verbally explains what is missing (or uses a new pen to include missing elements) and/or provides suggestions. Students can also take photos of the boards (not necessary if students work on SMART boards).

The instructor emphasizes what is necessary to “communicate” a complete solution and can then ask a couple of “what if” questions for the class to answer verbally and quickly.

This is then repeated for another “round” of problems to be solved. Depending on the content, the instructor can complete two rounds and start a third one for students to then complete individually at home.

At the end, there is a Q&A, the instructor reiterates what is necessary to “communicate” a complete solution, and the instructor reminds them that collectively, many questions of the assignment set have been solved; students are now in a good position to complete the assignment and bring questions/difficulties to the next class.

This activity can be used for the following:

Concepts in Mechanics:

  • Vector review
  • Static equilibrium with no torque (emphasis on forces, free body diagrams, correct vector/scalar equations, and numerical solving)
  • Static equilibrium with torque (emphasis on extended free body diagrams, choice of pivot, and correct vector/scalar equations)
  • 2D Kinematics
  • Two body translational Dynamics (emphasis on free body diagrams, and correct vector/scalar equations)
  • Circular Dynamics (emphasis on free body diagrams, and correct vector/scalar equations)
  • Conservation of Mechanical Energy
  • Conservation of Linear Momentum
  • Rotational Dynamics

Concepts in Waves & Modern Physics:

  • Simple Harmonic Motion: finding correct phase constant for SHM equation and using unit circle to find “all the locations and times in the first cycle that…”
  • Travelling Harmonic Waves: From reading “y vs x” or “y vs t” graphs, finding correct phase constant for THW equation, plotting “y vs x” or “y vs t” graphs
  • Doppler Effect
  • Interference and Diffraction
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Instructional Objectives

Students learn to build a conceptual model describing a Mechanics based situation and practice mathematical problem solving: Correct use of free body diagrams, translating the free body diagrams to correct vector/scalar equations to be solved, using appropriate algebra to numerically solve.

Workflow & Materials

Activity Workflow

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Group Problem Solving with Show and Tell

Link to CourseFlow Tool

Link

Contributor's Notes

Benefits

  • Socio-constructivist approach to learning.
  • Practicing modelling word problems into free body diagrams and then translating the free body diagrams to correct vector/scalar equations to be solved.
  • Emphasis on what forces belong on what body.
  • Students see “typical” problems that they will encounter on quizzes and tests (especially useful early in the Mechanics semester when new students are insecure).

Challenges

  • Students need help with labeling correct forces and including correct forces on the correct body
  • Students need help understanding vector vs scalar equations.
  • Students need help with respect to being critical to their numerical answer. Does this make sense? (For example, what does this negative acceleration mean in this context? Where is the block sliding? Faster ot slower?)
  • Teacher needs to manage time and assure that all groups remain engaged.

Tips

  • If this strategy is repeated often, then the time for students to set up is kept short. For Mechanics, I do this 7-9 times in a semester.
  • Do not wait for all groups to complete the task before ending a “round.” End the round when ay least each question has been completely solved once.
  • Have more complex (or alternate) versions of each question ready for the quick groups.
  • If you spot an error on the board, allow the students to continue (ie. Allow them to fail a bit) before jumping in.
  • For some topics, each round can be shorter if the numerical solving is cut out (eg. you can have them just do free body diagrams and correct vector/scalar equations).