Circular Motion

Core Sentence / 核心句

Circular motion requires a net radial force toward the instantaneous center of curvature.

\qquad \sum F_r=m\frac{v^2}{r}$$ ## Procedure / 步骤 1. mark the center；2. choose inward positive；3. draw only real forces；4. project them radially；5. add energy if speed changes with height。 ## Watch Out / 易错点 centripetal force 不是额外一种力；uniform circular motion 只有 speed 恒定，velocity 仍持续变化。 ## Mentioned In / 出现位置 - [[AP物理C力学第4次正课-连接体阻力与圆周运动入门#7. Centripetal Acceleration / 向心加速度|第4次正课 · circular motion entry]] - [[AP物理C力学第5次正课-圆周运动万有引力与质心#4. Vertical Circle / 竖直圆周|第5次正课 · vertical circle]] - [[AP物理C力学第11次正课-滚动天体运动与简谐振动开端#6. Circular Orbits / 圆轨道|第11次正课 · circular orbit]] ## Connected Notes / 连接 - [[Newton's Second Law]] - [[Vectors]] - [[Mechanical Energy Conservation]] - [[Orbital Motion]] - [[Rotational Kinematics]]