Notes:

The Change of State Concept Builder is an adjustable-size file that displays nicely on smart phones, on tablets such as the iPad, on Chromebooks, and on laptops and desktops. The size of the Interactive can be scaled to fit the device that it is displayed on. The compatibility with smart phones, iPads, other tablets, and Chromebooks make it a perfect tool for use in a 1:1 classroom.

Teaching Ideas and Suggestions:

This Concept Builder is intended for use in the middle to latter stages of a learning cycle on Newton's Second Law. It makes for an exceptional formative assessment of student understanding of the connection between forces and motion. Students are given a short description of an object's motion and an accompanying free-body diagram. The motion of the object changes and they are to predict what the new free-body diagram would look like if the object's motion to change in the manner described. They must pick a free-body diagram from a selection of five choices.

This Concept Builder was intended as an in-class activity. The Concept Builder includes 12 different situations, organized into two different ability levels. Teachers using the Concept Builder with their classes should preview the activity (or view the Questions in the separate file) in order to judge which levels would be most appropriate for their students. Our summary of the two levels is as follows:

• Master Level (moderate difficulty): Includes six situations in all. These include six situations involving various types of changes in state. Students must identify the free-body diagram associated with the change.
• Wizard Level (most difficult): Includes 12 situations. These include six situations of the Master Level plus six more situations involving various types of changes in state. Students must identify the free-body diagram associated with the change.

In order to complete a level, a student must successfully analyze each situation. If a student's analysis is incorrect, then the student will have to correctly analyze the same situation twice in order to successfully complete the level. This approach provides the student extra practice on situations for which they exhibited difficulty. Second, third, and subsequent attempts at the same situation will only differ in terms of the order of the choices. They are the same five answer choices each time but their order is shuffled.

As a student progresses through a level, a system of stars and other indicators are used to indicate progress on the level. A star is an indicator of correctly analyzing the situation. Once a star is earned, that situation is removed from the cue of situations to be analyzed. Each situation is color-coded with either a yellow or a red box. A red box indicates that the student has incorrectly analyzed the situation and will have to correctly analyze it twice before earning a star. A yellow box is an indicator that the situation must be correctly analyzed one time in order to earn a star. Once every situation at a level has been analyzed, the student earns a medal that is displayed on the Main Menu. This system of stars and medals allows a teacher to easily check-off student progress or offer credit for completing assigned levels.

The most valuable (and most overlooked) aspect of this concept-building activity is the Help Me! feature. Each situation is accompanied by a Help page that discusses in detail the specifics of the question. This Help feature transforms the activity from a question-answering activity into a concept-building activity. The student who takes the time to use the Help pages can be transformed from a guesser to a learner and from an unsure student to a confident student. The "meat and potatoes" of the Help pages are in the sections titled "How to Think About This Situation:" Students need to be encouraged by teachers to use the Help Me! button and to read this section of the page. A student that takes time to reflect upon how they are answering the question and how an expert would think about the situation can transform their naivete into expertise.

Related Resources

There are numerous resources at The Physics Classroom website that serve as very complementary supports for the Change of State Concept Builder. These include:
• Minds On Physics Internet Modules:
The Minds On Physics Internet Modules include a collection of interactive questioning modules that help learners assess their understanding of physics concepts and solidify those understandings by answering questions that require higher-order thinking. Assignments from the Newton's Laws module make for a great complement to this Concept Builder. They are best used in the middle to later stages of the learning cycle. We recommend assignments NL2, NL3, NL4, and NL5 as accompaniments to this activity. Visit the Minds On Physics Internet Modules.

Users may find that the App version of Minds On Physics works best on their devices. The App Version can be found at the Minds On Physics the App section of our website. The Newton's Laws module can be found on Part 2 of the six-part App series. Visit Minds On Physics the App.

• Curriculum/Practice: Several Concept Development worksheets at the Curriculum Corner will be very useful in assisting students in cultivating their understanding, most notably ...

Balanced vs. Unbalanced Forces
Net Force Help Sheet
Recognizing Forces
Free-Body Diagrams
Drawing Free-Body Diagrams

Visit the Curriculum Corner - Newton's Laws.

Additional resources and ideas for incorporating Change of State into an instructional unit on Newton's Laws  can be found at the Teacher Toolkits section of The Physics Classroom website.  Visit Teacher Toolkits.