Chapter 5 Rotation of a rigid body 第五章刚体的转动 RUD ROLL ER VERTICAL AXIS EL EVATOR PITCH AILERON ONGITUDINAL AXIS LATERAL AXIS
Chapter 5 Rotation of a Rigid Body 第五章 刚体的转动
§5-1 Motion of a rigid body刚体的平动、转动和定 轴转动 85-2 Torque The Law of Rotation rotational Inertia力矩刚体定轴转动定律转动惯量 §5-3 Applying the law of rotation转动定律的应用 85-4 Kinetic Energy and Work in Rotational Motion定轴转动的动能定理 85-5 Angular Momentum of a rigid Bod Conservation of Angular Momentum定轴转动 的刚体的角动量定理和角动量守恒定律
§5-5 Angular Momentum of a rigid Body Conservation of Angular Momentum 定轴转动 的刚体的角动量定理 和角动量守恒定律 §5-1 Motion of a Rigid body 刚体的平动、转动和定 轴转动 §5-2 Torque The Law of Rotation rotational Inertia 力矩 刚体定轴转动定律 转动惯量 §5-3 Applying the Law of rotation 转动定律的应用 §5-4 Kinetic Energy and Work in Rotational Motion 定轴转动的动能定理
教学基本要求 1.理解描述刚体定轴转动的基本物理量的定义和性质; 2.理解力矩、转动动能和转动惯量的物理意义; 3.掌握定轴转动的转动定律和角动量定理; 4.掌握定轴转动的角动量守恒定律和机械能守恒定律
1. 理解描述刚体定轴转动的基本物理量的定义和性质； 2. 理解力矩、转动动能和转动惯量的物理意义； 3. 掌握定轴转动的转动定律和角动量定理； 4. 掌握定轴转动的角动量守恒定律和机械能守恒定律。 教学基本要求
Now, we consider the motion of a body with a certain size and shape. 大小和形状! 上
Now, we consider the motion of a body with a certain size and shape: 大小和形状！
For simplicity(为简单),we ignore the deformation(形变).I general, the motion of the body is more complicated than that discussed above Whv? 猫坠楼,但不易受伤! neat
For simplicity（为简单）, we ignore the deformation(形变）. In general, the motion of the body is more complicated than that discussed above. Why? 猫坠楼，但不易受伤！
The body without deformation is called a rigid body. 铁石心肠 不可塑造 Its motion includes usually two types: (1) translation(平动); (2) rotation(转动)。 Examples: dancing, stang, motion of Earth, motion of electron in the atom world
The body without deformation is called a rigid body. (1) translation（平动）; (2) rotation（转动）。 Examples: dancing, skating, motion of Earth, motion of electron in the atom world,……. Its motion includes usually two types: 铁石心肠 不可塑造
851 Motion of a Rigid body 刚体的平动、转动和定轴转动 1. The model of a rigid body刚体模型 Rigid body(刚体): an ideal mode The distance between two points in a rigid body maintains constant forever. Thus the body has a perfectly definite unchanged shape and size. 刚体是一种理想模型:刚体是在任何外力作用下任意两点间 均不发生位移,形状大小均不发生改变的物体
1. The model of a rigid body 刚体模型 Rigid body（刚体） : an ideal model 刚体是一种理想模型：刚体是在任何外力作用下任意两点间 均不发生位移，形状大小均不发生改变的物体。 §51 Motion of a Rigid Body 刚体的平动、转动和定轴转动 The distance between two points in a rigid body maintains constant forever. Thus the body has a perfectly definite, unchanged shape and size
2. Translation Rotation of a rigid body 刚体的平动和转动 (1) Translation(平动) 看成质点 All particles describe parallel (平行) paths, and have the same velocity acceleration Therefore, the motion of any point of the body can represent the translational motion of entire(整个) rigid body. 水平飞行 (平动:刚体上所有点的运动轨迹都相, 可当作质点来处理。)
2. Translation & Rotation of a rigid body 刚体的平动和转动 (平动：刚体上所有点的运动轨迹都相， 可当作质点来处理。) All particles describe parallel （平行） paths, and have the same velocity & acceleration. Therefore,the motion of any point of the body can represent the translational motion of entire（整个） rigid body. (1) Translation（平动）: 水平飞行 看成质点
(2) Rotation: All particles describe circular paths around a line called the axis (ti) which may fixed or may changing its position during the motion. (转动:刚体上各点都绕某一轴 作圆周运动,转轴可能是固定 的也可能在运动中改变位置。) ∵ 圆周运动
All particles describe circular paths around a line called the axis（轴） which may fixed or may changing its position during the motion. (2) Rotation: (转动：刚体上各点都绕某一轴 作圆周运动，转轴可能是固定 的也可能在运动中改变位置。) 圆周运动