AP Physics 1 Unit Plan-Torque and Rotational Motion

Unit Title: Torque and Rotational Motion

Prerequisite Knowledge

• Newton's Laws of Motion
• Linear kinematics and dynamics
• Basic trigonometry

Unit Objectives

By the end of this unit, students should be able to:

1. Define and calculate torque.
2. Understand the conditions for rotational equilibrium.
3. Analyze rotational motion using angular kinematics.
4. Apply Newton's second law for rotation.
5. Understand the concept of rotational inertia.
6. Solve problems involving rotational dynamics and energy.
7. Explore the analogies between linear and rotational motion.

Unit Duration

• 2-3 weeks

Key Concepts

8. Torque ($\tau$)

   • Definition: $\tau =rF\sin \theta$
   • Lever arm and angle of force application

9. Rotational Equilibrium

   • Conditions for equilibrium: $\sum \tau =0$

10. Angular Kinematics

• Angular displacement, velocity, and acceleration
• Equations of motion for constant angular acceleration

11. Rotational Dynamics

• Newton's second law for rotation: $\tau =I\alpha$
• Rotational inertia ($I$)

12. Rotational Energy

• Kinetic energy of rotation: $K{E}_{\text{rot}}=\frac{1}{2}I{\omega }^2$
• Conservation of energy in rotational systems

13. Angular Momentum

• Definition: $L=I\omega$
• Conservation of angular momentum

Lesson Breakdown

Lesson 1: Introduction to Torque

• Objective: Define torque and understand its role in rotational motion.
• Activities:
  • Demonstration: Applying forces at different angles on a door.
  • Practice problems on calculating torque.
  • Discussion on real-world applications (e.g., wrenches, seesaws).
• Homework: Problems on torque calculation.

Lesson 2: Rotational Equilibrium

• Objective: Understand the conditions for rotational equilibrium.
• Activities:
  • Lab: Balancing a meter stick with weights.
  • Group activity: Solve equilibrium problems.
• Homework: Problems on rotational equilibrium.

Lesson 3: Angular Kinematics

• Objective: Analyze rotational motion using angular kinematics.
• Activities:
  • Derive angular kinematic equations.
  • Example problems: Rotating wheels and disks.
  • Lab: Measure angular displacement and velocity.
• Homework: Problems on angular kinematics.

Lesson 4: Rotational Dynamics

• Objective: Apply Newton's second law to rotational motion.
• Activities:
  • Derive $\tau =I\alpha$ and discuss rotational inertia.
  • Lab: Investigate rotational inertia with different objects.
• Homework: Problems on rotational dynamics.

Lesson 5: Rotational Energy and Angular Momentum

• Objective: Understand rotational energy and angular momentum.
• Activities:
  • Discuss kinetic energy of rotation and conservation of energy.
  • Lab: Explore conservation of angular momentum with rotating platforms.
• Homework: Problems on rotational energy and angular momentum.

Lesson 6: Review and Practice

• Objective: Consolidate understanding and prepare for assessment.
• Activities:
  • Group problem-solving: Mixed rotational motion problems.
  • AP-style multiple-choice and free-response questions.
  • Review torque and rotational dynamics.

Assessments

• Formative Assessments:

  • Quizzes on key concepts.
  • Lab reports and reflections.

• Summative Assessments:

  • Unit test covering all key concepts.
  • Project presentation on a real-world application of rotational motion.

Resources

• Textbook: AP Physics 1 textbook chapters on rotational motion.
• Online simulations (e.g., PhET Interactive Simulations).