L19 轉動 Rigid Body Rotation

Outline

1. MS2(Energy): Results(104), Preparation(106)
2. Hands on Demo: Euler Disk, Phitops, Tippe Tops
3. What is new? No longer use particle Model (object only described by Mass (m)
4. Key Point: Inertia: linear motion (inertial mass) & rotational motion (moment of inertia)
5. Inertia Demo: Students - linear & Rotations (3 ways)
6. Demo Physics Girl: Tippe Tops
7. Lecture Slides
8. PHET: Torque Inertia, Angular Momentum

INERTIA 主要概念:慣性

Resistance to Change 改變的阻力Gǎibiàn de zǔlì Defn: the tendency of a body to preserve its state of rest or uniform motion unless acted upon by an external force (ref: Dictionary.com) Physics 1st use: 1713 Johann Kepler 約翰·克普勒 (开普勒）(German astronomer) Inertial Mass (m): Ability of an object to resist a change in translational motion (Scalar) Moment of Inertia (I): Ability of an object to resist a change in its rotational motion (Tensor)

View Graphs: Rigid Body Rotation (Knight Chapter 12 to Slide 100)

Kinematics

Spinning Wheels (Julius Sumner Miller)

Angular Momentum