Teacher Notes for Newton's Laws

 

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

 

Unit Overview

We estimate this to be a 14-day unit. An additional day should be added for an exam. There are three primary goals for this time:

1. To understand that forces result from mutual interactions between an object and its surroundings and so to determine which forces act upon an object one must ask how that object is interacting with other objects in its surroundings.
2. To develop the skill of analyzing a situation, identifying the individual forces that are present on the identified object(s), constructing a free-body diagram to represent the relative magnitude and direction of the forces, and relating the individual force values to the object's acceleration.
3. To establish a firm belief in the idea that forces, when unbalanced, cause an acceleration. And that objects moving at a constant speed are not necessarily acted upon by a force and are certainly not experiencing more force in the direction of motion than force that opposes the motion.

The above is often described as Newton's three laws of motion and is presented above in reverse order - 3^rd, then 2^nd, and finally 1^st.

The activities that we have selected for our Lesson Plans and Learning Outcomes and Activities are primarily focused on supporting the development of these three goals. But like the 1D Kinematics unit, there are likely enough activities on our website to prolong this unit for many more days. As such, you will need to be a bit selective. You don't need to do all the activities. All the activities have value for some classrooms. But not all classrooms need to do all the activities. For instance you may find that you need more help with analyzing forces and applying Newton's second law. If so, you will find several additional supports than those described in the Lesson Plans.


 

It's CONCEPTUAL Physics

In designing this unit, we have slowed things down and provided considerable simplification of the mathematics and problems. Students will do the usual math when it comes to Newton's second law and a = F_net/m. In all situations, there are no instances in which they have to solve for an individual force value. The problems are written such that they must first solve for net force and then solve for acceleration. In some instances, they will also need to determine the mass from the weight before calculating the acceleration. There is a lot of scaffolding involved in most problems. Unlike our algebra-based Physics course, there is no mention of a coefficient of friction.


 

The Calculator Pad (a.k.a., CalcPad)

When it comes to solving Physics word problems or simply conducting a mathematical analysis of a physical situation, our CalcPad section is the go-to resource. We have nearly 150 ready-to-use problems organized into 20 different short problem sets for the topic of Newton's Laws. With a Task Tracker subscription, you can organized the pre-made problems into your own problem sets and even write your own problems. We have created six different custom problems sets for this unit that represent a re-organization of those ~150 problems; the last problem set is actually a review of all the math. The problem sets are simple and short. In some instances, we modified the original problems to make them more suitable for Conceptual Physics students. Such modifications included re-coding to make the randomly-generated numbers a bit more pleasing looking (e.g., a 41.9-N force has become a 40-N force) and providing scaffolding for most problems so that students first calculate the net force and then calculated the acceleration.

We suspect that if we have erred, we erred on the side of providing problems that are too simplified (just our guess). Depending on your level of student, you may wish to add more rigorous problems. With a Task Tracker subscription, you can easily assign additional problems to your students and even edit our sets by removing or adding problems to them. There are directions and videos for doing so in the Teacher Resources section of your Task Tracker account.


 

Have You Tried a Concept Checker Lately?

Read that sentence again. We said "Concept Checker". That's intentionally different than Concept Builder. A Concept Checker coordinates with a Physics simulation and an accompanying Student Activity Sheet. It's a way to bring closure to a lesson. Allow students to manipulate the simulation and explore. Provide them the Student Activity Sheet (or comparable tool) to promote some guided inquiry. Take some time to post-process their exploration to insure students are understanding the concepts presented by the simulation. Then assign them the Concept Checker. If you have a Task Tracker account, students can begin at school and finish at home. They will be able to log in and continue where they left off.


 

Looking for a Project Idea?

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 project that we think would quickly pique students interest is our Falling Bodies 1D Interactive. This Interactive provides students with a numerical modeling tool for exploring open-ended questions that pertain to the falling motion of an object. The Interactive is accompanied by a ready-to-use Student Activity Sheet with an accompanying Scoring Rubric. The activity can even be downloaded as a Microsoft Word document and modified to your liking.

Visit Falling Bodies 1D Interactive.



 

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. Science Reasoning Center: Friction
   Describes a complex set of three experiments exploring the effect of several variables upon the amount of friction experienced by a wooden block dragged across a surface. Data is presented in the form of three different data tables. Students must analyze the results and identify appropriate conclusions.
2. Physics Interactives: Falling Bodies - 1D
   Looking for a student project? The Falling Bodies 1D interactive is a numerical modeling program that models the falling motion of an object in the presence of air resistance. It is perfect for allowing students to ask What if ...?-styled question and explore the answer. What if the skydiver had a greater mass? What if there was no air resistance? What if the fall occurred on the moon instead of on Earth? 
3. Concept Builder: Normal Force Card Sort
   Students analyze several physical situations in order to determine the relative strength of the normal force experienced by an object. 
4. Minds On Physics: Mission NL6 on Mass and Weight
   Students distinguish between the concepts of mass and weight and calculate the weight from the mass and vice versa.
5. Minds On Physics: Mission NL7 on Newton's Second Law
   Students identify the proportional relationships between acceleration, net force, and mass and use the relationship to predict the effect of changes in mass or net force upon acceleration.

 

Science Reasoning Center Activities

We have several Newton's Laws activities at our Science Reasoning Center. These provide a slightly different approach than Concept Builders or Minds On Physics. They tend to de-emphasize  conceptual development and emphasize 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. Several of them specifically target NGSS performance expectations; see Cart, Bricks, and Bands and Fan Cart Study 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.


 

Teacher Presentation Pack

We're not going to lie. We are biased. We think our Teacher Presentation Pack is an exceptional offering. You will find a wide collection of Slide Decks and animations for use in your classroom. Once downloaded, you can modify and customize them as needed. They can make your presentations more efficient. One or two slides might serve as quick reference prior to starting an activity. Or an animation might make a concept come alive.


 

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)