Teacher Notes for Momentum and Collisions

 

Lesson Plans || Learning Outcomes and Activities || Teacher Notes || Labs

 

Unit Overview

We estimate this to be a 13-day unit. An additional day should be added for an exam. There are three primary goals for this time:
 

1. To understand the concepts of a momentum change and an impulse and to relate these two quantities to one another in order to predict a numerical value of force, time, mass, or velocity change and to predict the impact that a change in a collision parameter will have upon the collision force.
2. To use momentum conservation to analyze a collision or an explosion occurring in an isolated system to predict an unknown collision parameter or the effect of a change in mass or speed upon the outcome of the collision or explosion.
3. To combine a momentum analysis with other Physics (vectors, kinematics, Newton's laws, energy concepts, etc,) in order to analyze a complex physical scenario.

 

Physics Interactives

We love our simulation section and it has become quite popular in the past decade. The blending of a simulation with a Student Activity sheet and a Concept Checker opens the door for some engaging lesson plans. We have suggested the use of three simulations with the corresponding Student Activity sheet and Concept Checker. Our original vision for how this triad of tools would be used goes something like this:
   

Labs

We have suggested a number of labs. Most require the use of motion detectors. In situations where motion detectors are not available, our Teacher Guides include some ideas for alternative procedures. See our Labs page for links to the Teacher Guides. 

Teachers may be interested in adding a lab on elastic collision analysis. You will find our Teachers Guide on the topic here.


 

The Honors Difference

No matter what level one teachers, it can be profoundly stated that Physics is physics. That is, momentum conservation has the same meaning in a Conceptual Physics class as it does in the Honors Physics class. But one real difference is that the Honors Physics students typically have considerably more mathematical skill and comfort, allowing teachers to use more applications of the momentum conservation idea. 

In this unit, those higher applications most visible in the last learning outomes found on our Learning Outcomes page. Momentum plus problems, 2D collision problems, and elastic collision problems are not common place in an on-level Physics course but show up here in our Honors Physics course. We have added a few additional days to accomodate these added topics. More days may be needed.


 

What Comes First - Energy or Momentum?

This unit has been placed prior to the unit on energy. This is common practice for high school physics textbooks and courses. College textbooks and courses often flip the order, placing the energy unit prior to the momentum unit. The latter order makes considerable sense because of the inclusion of topics like elastic collisions and momentum plus (our name for it) problems in college courses (and in our Honors Physics course). Each of these topics involve energy and momentum analyses.

We have followed the order set by our own "textbook" (the Tutorial section) and placed momentum as the unit prior to energy. It makes the topic of elastic collisions a bit awkward but nothing that can't be done without slipping in a new equation (KE=0.5*m*v^2). It does however limit the number of momentum plus problems that we can include since energy conservation has not yet been covered. As is our practce, we invite teachers to make their own decisions as to which works for them.


 

Perfectly Elastic Collisions?

We admit it's not perfect but we did it anyways. We placed a learning outcome for elastic collisions in this unit prior to coverage of the topic of energy. We did do it half-gracefully, providing an equation for calculating kinetic energy in the first exposure. But admittedly, it was awkward. You are welcome to save this topic until the energy unit or go ahead an follow our lead. If it is the latter, we would highly recommend the simulation and Activity Sheet titled The Elasticity of Collisions. Additionally, you might find the Colliding Carts activity in the Science Reasoning Center to be a welcome inclusion.


 

NGSS and the Science Reasoning Center

We have several Momentum and Collisions activities at our Science Reasoning Center. These provide a slightly different approach than Concept Builders or Minds On Physics. They tend to emphasize less conceptual development and more scientific processing, data interpretation, experimental analysis, etc. They often make great follow-ups to labs and can sometimes be used as an introduction to a topic. For most topics, they are great accompaniments to an NGSS curriculum. Check out our Marshmallow Launcher, our Engineering Safer Helmets, and our Collisions activities as examples. If you have a Task Tracker subscription, visit the Teacher Resources section in order to quickly preview the activity and navigate through all the questions. You will also find information there about NGSS alignments.


 

Looking for a Project?

Many teachers like to provide students with open-ended projects. Projects often excel at fostering student creativity, increasing student engagement, affording opportunities for students to explore the connection between Physics and their daily lives, and providing alternative means of assessing student understanding.

​One common project for a momentum unit is an egg drop project. Numerous project ideas can be found through a simple Google search. While we don't have anything on our site in the form of an Activity Sheet or Project Guidelines, we do have one supporting page for those classrooms that do undertake an Egg Drop project. Our Egg Drop Simulation might serve as an effective follow-up to such a project. The simulation is accompanied by a Student Activity Sheet. The activity sheet has been converted into a Concept Checker.

 

Other Resources

There are a few resources that we did not list in our Lesson Plans and Learning Outcomes and Activities that you may find to be very helpful. These include:
 

1. Physics Interactives: Egg Drop
   This simulated egg drop activity allows a learner to explore the variables that result in a safe landing or a fractured or broken egg. The accompanying activity sheet emphasizes the use of science reasoning skills to understand the physics behind an egg drop activity.
2. CalcPad: Momentum Problem Sets
   We have 15 problem sets in the Momentum section of the Calculator Pad. We created seven custom problem sets from these 15 sets. There are so many more problems we didn't use. Teachers may find something that is perfect for their need. If you have a Task Tracker subscription you can easily create your own problem set or edit the seven that we have made.

 

Teacher Presentation Pack

Here we go again ... throwing in an advertisement in the middle of a Teacher Notes page. But while we are advertising a for-sale item, we are also promoting an item that will potentially save the buyer a load of time. It's our Teacher Presentation Pack. It's a well-worth-the-cost tool for any Physics teacher. But for the early-career and cross-over Physics teacher, it's a life saver ... or at least a time saver. It includes a large collection of Slide Decks, Lesson Notes, animations, and graphics for use in your classroom. Once downloaded, you can modify and customize the Slide Decks as needed. The slides are highly organized and (mostly) graphical; they make great graphic organizers for any student, and especially for the struggling student. Learn more.





 

Also Available ...

Physics teachers may find the following for-sale tools to be useful supplements to our Lesson Plan and Pacing Guide section:

 

1. Task Tracker Subscription (annual purchase)
   A subscription allows teachers to set up classes, add students, customize online assignments, view student progress/scores, and export student scores. Task Tracker accounts allow your students to begin assignments in class or at school and to finish them at home. View our Seat and Cost Calculator for pricing details.
    
2. The Solutions Guide
   We publish a free curriculum with >200 ready-to-use Think Sheets for developing physics concepts. The Solutions Guide is a download containing the source documents, PDFs of source documents, and answers/solutions in MS Word and PDF format. An expanded license agreement is included with the purchase. (Cost: $25 download)
    
3. Teacher Presentation Pack
   This is a large collection of downloadable content packed with nearly 190 Microsoft PowerPoint slide decks, the corresponding Lesson Notes (as PDF and fully-modifiable MS Word format), about 170 animations (in .gif, .png, and .mp4 file formats), a countless number of ready-to-use images (including the original source documents that would allow for easy modification of those images), and a license that allows teachers to modify and use all the content with their classes on password-protected sites (such as course management systems).  (Cost: $40 download)
    
4. Question Bank
   We distribute a Question Bank that includes more than 9300 questions neatly organized according to topic. The Question Bank is the perfect tool for busy teachers or new teachers. Even if you don't use the website with your classes, the Question Bank will assist you in quickly putting together quizzes, tests and other documents with high-quality questions that target student's conceptions of physics principles. And if you do use The Physics Classroom website, the Question Bank is the perfect complement to the materials found at the website. (Cost: $25 download)