At a Glance


  • STEM
  • Physics

Instructional Level

  • College & CEGEP


  • Mechanics

Tasks in Workflow

Social Plane(s)

  • Individual
  • Group

Type of Tasks

  • Collecting & seeking information
  • Solving problems
  • Analyzing
  • Reviewing & assessing peers
  • Creating & designing
  • Revising & improving

Technical Details

Useful Technologies

  • Visual Classrooms

Class size

  • Small (20-49)


  • Multiple class periods (2-3 classes)

Instructional Purpose

  • Application & knowledge building
  • Assessment & knowledge refinement


Students are pre-assigned to groups of 4-6 persons. Individually, students find or take an image or a video that captures the interaction of two objects in 3 separate periods of interaction: before, during and after. Students then draw a free-body diagram (FBD) of the two objects in the ‘during’ period of interaction, along with a written explanation of the interaction. Students upload their diagrams and explanations into an online collaborative platform (OCP).

As a group, students assess and peer-review each submission. Students then re-assess their FBDs and make changes accordingly.

The instructor presents the class with conceptual questions relating to momentum. Groups then discuss and answer the questions at a whiteboard or interactive board, providing a written rationale for their response. They then compare their answers to the conceptual questions to their previous analysis of interacting objects, identifying similarities between the two.

This activity then has two possible out of class follow up activities: Preparing a test question, or correcting their original FBDs with another step of peer review and instructor feedback.

Instructional Objectives

Students will learn to determine whether or not a system is isolated, and the consequences for conservation of momentum. They will learn to explicitly attend to a system’s “before” and “after” states when analyzing it momentum, and to recognize elastic and inelastic interactions.

Workflow & Materials


Activity Workflow

View on CourseFlow

Contributor's Notes

Rhys Adams

Rhys Adams

Vanier College, Montreal, QC


This engages students using online collaborative technologies. These technologies can be used to monitor the progress of groups as they complete the activity.


An online collaborative platform is required. Students are expected to posses a personal computer, laptop, or tablet (with which they can access the online platform in class), along with a smart phone or camera.


To ensure the selected scenarios represent a wide range of possible collisions, you may require that each group have scenarios representative of (i) collisions between disproportionate masses, (ii) an approximately elastic collision, (iii) a totally inelastic collision and (iv) a case with an object that has no initial velocity.

Applied Strategies


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