The Torque 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 Concept Builder 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 designed as a follow-up to our Torque Concept Builder and a pre-cursor to the use of our Getting a Handle on Torque and Torque-ing About Rotation Concept Builders. The emphasis of this activity is to analyze the torques on a beam to determine if the torques are balanced and if the beam will undergo an angular acceleration. Students are given information about the torques (Apprentice Level) or about the forces and the distance from the point of application of the forces to the fulcrum. They must carry out a rather straight-forward analysis to determine if the torques are balanced or not. In the Apprentice Difficulty Level, a + or - sign is used to convey information about the direction of the torques. In the Master and Wizard Difficulty Levels, a force arrow is displayed at the point of application and its direction is indicated by the arrow. 

This Concept Builder consists of 48 different questions that are organized into 12 different Question Groups and spread across three different difficulty levels. The three difficulty levels are differentiated as follows:
  • Apprentice Difficulty Level  Question Groups 1-4: Students are given two torques and must analyze the torques experienced by an object in order to determine if the object is experiencing an angular acceleration.
  • Master Difficulty Level  Question Groups 5-8: Students are given two forces and their point of application and must determine if the torques balance and whether there is an angular acceleration.
  • Wizard Difficulty Level  Question Groups 9-12: Students are given three or four forces and their point of application and must determine if the torques balance and whether there is an angular acceleration.

Before using the Concept Builder with your classes, we recommend that teachers attempt each of the levels in order to determine which are most appropriate for your classes and what pre-requisite understanding a student must have in order to complete it. Alternatively, the questions are provided in a separate file for preview purposes. The levels become progressively more difficult and attention must be given to both the direction and the magnitude of the torques from each level to the next. All levels should be appropriate for most classes. AP Physics 1, Honors Physics, and IB Physics classes may use this as a stepping stone before attempting the more difficult Calculator Pad problems on the same topic.

In order to complete a difficulty level, a student must correctly analyze each question in that level. If a student's analysis is incorrect, then the student will have to correctly analyze the same or very similar question twice in order to successfully complete the level. This approach provides the student extra practice on questions for which they exhibited difficulty. As a student progresses through a level, a system of stars and other indicators are used to indicate progress on the level (displayed for Task Tracker users). A star is an indicator of correctly analyzing the question. Once a star is earned, that question is removed from the queue of questions 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 question and will have to correctly analyze it twice before earning a star. A yellow box is an indicator that the question must be correctly analyzed one time in order to earn a star. Once every question in an activity has been analyzed, the student earns a Trophy which is displayed on the Main Menu. 

The most valuable (and most overlooked) aspect of this Concept Builder is the Help Me! feature. Each Question Group is accompanied by a Help page that discusses 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

We do not have a lot of resources on the topic of Rotational Motion at The Physics Classroom website. What we do have is listed below. We hope to be adding more in the future. 
  • The Calculator Pad:
    Our recently-revised Calculator Pad section has a complete collection of problems on all sorts of torque and rotation topics. There are 14 problem sets on the topic of Torque and Rotation. Each successive problem set becomes progressively more difficult than the one before it and they would make great follow-ups to this Concept Builder.

    View Rotation and Torque at The Calculator Pad.

  • Physics Interactives:
    The Balance Beam Interactive provides a tool to investigate the factors that affect the ability for different masses placed upon opposite sides of a balance beam to balance. Masses can easily be dragged to hooks along the beam, causing the beam to rotate downwards on the side it is placed. The challenge involves placing a different mass on the opposite side to counteract the first mass. By so arranging the masses to obtain balance, a learner can look for the patterns in the data - amount of mass and location of the mass from the fulcrum - in order to discover the rule of balance. The simulation includes a built-in quiz and an accompanying Concept Checker.

    Visit Balance Beam Interactive.