第八章 点的合成运动.ppt

Chapter 8: Compositive
motion of a particle
Theoretical mechanics
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第八章点的合成运动
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§8–1 Concept positive motion of a particle
§8–2 Theorem position of velocities of a particle
§8–3 Theorem position of accelerations when the convected motion is translation
§8–4 Theorem position of accelerations when the convected motion is rotation
Lesson for problem solving
Chapter 8: Compositive motion of a particle
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§8–1 点的合成运动的概念
§8–2 点的速度合成定理
§8–3 牵连运动为平动时点的加速度合成定理
§8–4 牵连运动为转动时点的加速度合成定理
习题课
第八章点的合成运动
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§8-1 concept positive motion of a particle
system:
1) Static coordinate system: A coordinate system fixed to the earth ground
is called Static coordinate system (SCS).
2) Moving coordinate system: A coordinate system fixed to a moving object
relative to the earth ground is called moving coordinate system (MCS).
For example, a running car.
In the previous two chapters, we have considered the motion of a particle or a rigid body with respect to a system of fixed coordinate axes. In practice, however, we often observe the motion with respect to a moving body. For example, we observe the motion of an flying airplane from a moving car, or observe the motion of raindrops from a traveling train.
Why do obtain different results when we observe the motion a object on different coordinate systems or reference objects? It is known that there may exist relationship between two different objects. Next, we are going to study the relationship between the motions of an object and the reference object. First of all, we begin with the introduction of some concepts.
Kinematics
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§8-1 点的合成运动的概念
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:把固结于地面上的坐标系称为静坐标系,简称静系。
:把固结于相对于地面运动物体上的坐标系,
称为动坐标系,简称动系。例如在行驶的汽车。
前两章中我们研究点和刚体的运动,一般都是以地面为参考
体的。然而在实际问题中,还常常要在相对于地面运动着的参
考系上观察和研究物体的运动。例如,从行驶的汽车上观看飞机的运动等,坐在行驶的火车内看下雨的雨点是向后斜落的等。
为什么在不同的坐标系或参考体上观察物体的运动会有不同的结果呢?我们说事物都是相互联系着的。下面我们就将研究参考体与观察物体运动之间的联系。为了便于研究,下面先来介绍有关的概念。
运动学
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kinds of motion and their velocities and accelerations
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