[熱身賽第一輪] 簡單擺和物理擺 [Warm-up Round 1] Simple and Physical Pendulums

unit: Oscillations topic: Simple and Physical Pendulums learning objective: Describe the properties of a physical pendulum. essential knowledge: A physical pendulum is a rigid body oscillating about a fixed axis. For small amplitudes, its period is $T_{phys} = 2\pi\sqrt{I/(m g d)}$, where $I$ is moment of inertia about the pivot and $d$ is distance from pivot to center of mass. The restoring torque is $\tau = -m g d \sin\theta$.