# Day 63: Momentum Bar Graphs vs. Tables

*College-Prep Physics:* Yesterday we did the Inventing Momentum progression and developed momentum bar graphs. But today I had to arrive at school late because my own kids’ school had a weather delay (freezing rain). So I needed something meaningful for students to do with the sub. I found and modified 2 activities from The Physics Classroom and added a third.

However, the activities used momentum tables rather than momentum bar graphs. Since the kids would be with the sub, I figured a little extra hand-holding from the activity would be OK. It actually worked out well, in my opinion. Now my thinking is that bar graphs are great visual tool to introduce and develop the concept of momentum (as in the progression linked above), but for standard problem solving, momentum tables are a cleaner way to organize all the information involved. I also liked how the table also asks for momentum changes and total change. It was something I stressed during this year’s Inventing Momentum progression that I hadn’t in previous years.

Here’s my version of the activity. (I edited out bits that mentioned impulse, since we haven’t done that yet. I added the section on Explosions.) — Momentum Activity 2015

The Physics Classroom simulation and the original activities are here: Collision Carts

**What are your thoughts on graphs vs. tables?**

(PS: Yes, I’m back to doing momentum before energy. Why? Because despite the fact that momentum is a vector quantity, there is only ONE kind of momentum. I think kids are more easily trickiness of positive/negative momentum than they are in identifying all the types of energy present in a system at any given time.)

*NGSS Science and Engineering Practices:
#2. Developing and using models*