In this lecture, we consider the motion of a 3D rigid body. We shall see that in the general three dimensional case, the angular velocity of the body can change in magnitude as well as in direction, and, as a consequence, the motion is considerably more complicated than that in two dimensions. Rotation About a Fixed Point We consider first the simplified situation in which the 3D body moves in such a way that there is always a point, O, which is fixed. It is clear that, in this case, the path of any point in the rigid body which is at a

本章主要介绍三维实体修改及编辑命令（Solids Editing）。 学习命令：并集（Union）、差集（Subtract）、 交集（Intersect）、拉伸面（Extrude Faces）、移 动面（Move Faces）、偏移面（Offset Faces）、 删除面（Delete Faces）、旋转面（Rotate Faces）、 倾斜面（Taper Faces）、着色面（Color Faces）、 复制面（Copy Faces）、着色边（Color Edges）、 复制边（Copy Edges）、压印（Imprint Body）、 清除（Clean Body）、分割（Separate Body）、抽 壳（Shell Body）、检查（Check Body）、圆角 （Fillet）、倒角（Chamfer）、三维阵列（3D Array）、三维镜像（Mirror 3D）、三维旋转 （Rotate 3D）、对齐（Align）等

本章主要介绍三维实体修改及编辑命令(Solids Editing)。 学习命令:并集(Union)、差集(Subtract) 、交集(Intersect)、拉伸面(Extrude Faces)、 移动面(Move Faces)、偏移面(Offset Faces) 、删除面(Delete Faces)、旋转面(Rotate Faces )、倾斜面(Taper Faces)、着色面(Color Faces 、、、 )、复制面(Copy Faces)、着色边(Color Edges )、复制边(Copy Edges)、压印(Imprint Body )、清除(Clean Body)、分割(Separate Body) 、抽壳(Shell Body)、检查(Check Body)、圆◎ 角(Fillet)、倒角(Chamfer)、三维阵列(3D Array)、三维镜像(Mirror 33D)、三维旋转( Rotate3D)、对齐(Align)等

一、单项选择题（本大题共 25 小题，每小题 1 分，共 25 分） 在每小题列出的四个备选项中只有一个是符合题目要求的，请将其代码填写在题后的括号内。错选、 多选或未选均无分。 1.HTML 语言中，设置链接颜色的代码是（ C ） A. B. C. D

October 22, 2001 Personal IdentityⅢ . Review soul criterion and body criterion Soul criterion: x is the same person as y iff and y have the same soul. Problems: i)There is no way to establish body-soul correlations; and no way to establish personality correlations. So soul criterion doesn't make sense of our practices of recognizing and identifying people ii)We have no special access to souls, so even in our own case we can't be sure it's the same soul \inside\ us whenever we are conscious. ii) The problem of identity is \pushed back\: what is it for person-stage x to have the same soul as person-stage y? What makes for sameness of souls? Body criterion: x is the same person as y iff x and y have the same living human body

In lecture D9, we saw the principle of impulse and momentum applied to particle motion. This principle was of particular importance when the applied forces were functions of time and when interactions between particles occurred over very short times, such as with impact forces. In this lecture, we extend these principles to two dimensional rigid body dynamics. Impulse and Momentum Equations Linear Momentum In lecture D18, we introduced the equations of motion for a two dimensional rigid body. The linear momen- tum for a system of particles is defined

It should provide drivers with good operating condition and comfort working environment; It should isolate vibration, noise, waste gas and harsh climate and provide passengers with comfort riding environment; It should keep the completeness of cargo and make them easy to load and unload; The structure of body and its equipment should ensure the safety of driving and reduce the influence of an incident. The reasonable outer shape of body can effectively steer the surrounding current and should improve the dynamic characteristics, fuel economy and driving stability. It should also improve the cooling condition of engine and ventilation inside the cab

12.1 Moment of momentum of a particle and its system 12.2 The moment of inertia of a rigid body against an axis 12.3 theorem of moment of momentum 12.4 Differential equation of a rigid body rotating about a fixed axis 12.5 Theorem of moment of momentum of a system of particles relative to the center of mass 12.6 Differential equations of motion in a rigid body plane

In this lecture, we will revisit the principle of work and energy introduced in lecture D7 for particle dynamics, and extend it to 2D rigid body dynamics. Kinetic Energy for a 2D Rigid Body We start by recalling the kinetic energy expression for a system of particles derived in lecture D17

In this lecture, we will start from the general relative motion concepts introduced in lectures D11 and D12. and then apply them to describe the motion of 2D rigid bodies. We will think of a rigid body as a system of particles in which the distance between any two particles stays constant. The term 2-dimensional implies that particles move in parallel planes. This includes, for instance, a planar body moving within its plane