Torque & Rotational Dynamics

Essential Questions

• Why does it matter where a door handle is placed?

• Why are long wrenches more effective?

• What do mobiles have in common with the Grand Canyon Skywalk?

• Why does a tightrope walker use a long pole?

• What keeps a bicycle balanced?

• Why do planets move faster when they travel closer to the sun?

• What do satellites and projectiles have in common?

• What do ice skaters do with their arms when they want to spin faster?  Why?

Learning Objectives

Rotational Kinematics

• Describe the rotation of a system with respect to time using angular displacement, angular velocity, and angular acceleration.

Connecting Linear and Rotational Motion

• Describe the linear motion of a point on a rotating rigid system that corresponds to the rotational motion of that point, and vice versa.

Torque

• Identify the torques exerted on a rigid system.

• Describe the torques exerted on a rigid system.

Rotational Inertia

• Describe the rotational inertia of a rigid system relative to a given axis of rotation.

• Describe the rotational inertia of a rigid system rotating about an axis that does not pass through the system’s center of mass.

Rotational Equilibrium and Newton’s First Law in Rotational Form

• Describe the conditions under which a system’s angular velocity remains constant.

Newton’s Second Law in Rotational Form

• Describe the conditions under which a system’s angular velocity changes.

Printable Learning Targets