OpenSciEd Unit 8.1 · Lesson 13 · 13.B
Iterate cushioning structure
From Teacher Edition
Facilitation guidance from the lesson plan — what to notice in student thinking and how to respond while teaching.
Building towards
13.B Develop and use subsystem models (free body diagrams) to represent how the peak contact forces on different objects in a collision compare when they have different cushioning structures between them.
What to look / listen for
Look for a system model that includes the following structures and subsystems:
Look for free body diagrams. In every approach used, the length of the force arrows should be shorter than any previous condition. One approach would be to treat the three-ring cushioner as a single subsystem. If so, look for the following in student responses.
Another approach would be to treat the three-ring cushioner as three separate subsystems. If so, look for the following in student responses.
What to do
For students who struggle with creating these free body diagrams, pair them up with another student who has been finding success with developing these diagrams and ask them to compare their models using the "partner feedback process" from slides D and E they used in lesson 10. This will provide a structured way for each student to share their diagram, compare each other’s diagrams, ask questions, and then revise their models.