Category Archives: Momentum

MTM Day 1

This year I am experimenting with a new progression in my physics classes. We started out with the Data Analysis or Scientific Thinking unit of the Modeling material, which I heavily supplemented with the Patterns Approach to Physics material. This unit took us approximately two weeks (90 minute, A-B block schedule) to complete.

After that we moved on to the Constant Velocity Model, with our primary focus being on interpreting and creating several different representations to represent the motion of objects moving with constant velocity. Some modelers start with this unit instead of the Scientific Thinking unit, but I love teaching data analysis to my students and feel that it helps acquaint them with the level of math necessary for the course. This year the CVM unit took me 10 classes (a couple of those were lost to school assemblies) to complete.

The traditional modeling curriculum then finishes up classic 1D kinematics by launching into a unit on Uniform Acceleration. However, after looking into several resources (Matter and Interactions, Six Ideas that Shaped Physics, Andy Rundquist, etc) I decided to divert and instead discuss Momentum next with my students. I feel like several of the sticking points from the force units will be resolved by using momentum as a spring-board into the other topics in physics.

For each unit I have been doing my best to follow in the footsteps of Kelly O’Shea and Casey Rutherford by making packets of all most of the materials students will receive throughout the unit. This helps them keep everything in one place and gives them a great study packet. Here is my packet for the Momentum Transfer Model borrowed heavily, but greatly reorganized, from the Modeling materials and from Kelly’s packet. I am not entirely happy with the packet right now as I need to find some good Impulse problems to include, but other than that I am very satisfied.

To introduce students to momentum we did a lab that investigates the motion of bowling balls. Typically, this is the paradigm lab for the unit on balanced forces, which always seemed a little out-of-place to me. Using this lab as an introduction to Momentum felt much more natural. After we had shared our findings it lead into a quick demonstration using a hover puck and then to Newton’s 1st Law. I love the way this sequence has come together just in the first day.

Next time, we will use a PhEt simulation to walk-through the derivation of the momentum equation similar to how it is introduced in the Six Ideas that Shaped Physics.