点击切换搜索课件文库搜索结果(5590)
文档格式:PPT 文档大小:72.5KB 文档页数:3
风动力下结构必然产生响应。一般情况 下,由于结构阻尼的存在,响应到达最大值 后又返回从而形成来回振动,虽然风力愈大, 但总是返回形成振动。但在某些情况下,风 力中产生负阻尼成分,如果风速到达某临届 值时,负阻尼大于结构的正阻尼,此时运动 向一个方向愈演愈烈而不返回,直至破坏, 产生空气动力失稳式效应。此时的风速,称 为临界风速,这种现象风工程中称为驰振或 颤震(弯扭耦合)
文档格式:PPT 文档大小:205.5KB 文档页数:10
一、选择题1,B2,3,C 二、填空题1,5.13,0.71,2,(1)O2,600m/s,H2,2400m/s; (2)具有从0到无穷大所有速率氧分子的概率,3(1)分子当作质点,不占体积(2)分子之间除碰撞的瞬间外,无相互作用力。(忽略重力)(3)分子之间碰撞是弹性碰撞(动能不变)
文档格式:PDF 文档大小:80.54KB 文档页数:6
In this course we will study Classical Mechanics. Particle motion in Classical Mechanics is governed by Newton's laws and is sometimes referred to as Newtonian Mechanics. These laws are empirical in that they combine observations from nature and some intuitive concepts. Newton's laws of motion are not self evident. For instance, in Aristotelian mechanics before Newton, force was thought to be required in order
文档格式:PDF 文档大小:97.24KB 文档页数:6
is a vector equation that relates the magnitude and direction of the force vector, to the magnitude and direction of the acceleration vector. In the previous lecture we derived expressions for the acceleration vector expressed in cartesian coordinates. This expressions can now be used in Newton's second law, to produce the equations of motion expressed in cartesian coordinates
文档格式:PDF 文档大小:107.72KB 文档页数:8
In lecture D2 we introduced the position velocity and acceleration vectors and referred them to a fixed cartesian coordinate system. While it is clear that the choice of coordinate system does not affect the final answer, we shall see that, in practical problems, the choice of a specific system may simplify the calculations considerably. In previous lectures, all the vectors at all points in the trajectory were expressed in the
文档格式:PDF 文档大小:85.64KB 文档页数:5
In this lecture we will look at some applications of Newton's second law, expressed in the different coordinate systems that were introduced in lectures D3-D5. Recall that Newton's second law F=ma, (1) is a vector equation which is valid for inertial observers. In general, we will be interested in determining the motion of a particle given
文档格式:PDF 文档大小:112.27KB 文档页数:8
In this lecture we will look at some other common systems of coordinates. We will present polar coordinates in two dimensions and cylindrical and spherical coordinates in three dimensions. We shall see that these systems are particularly useful for certain classes of problems Like in the case of intrinsic coordinates presented in the previous lecture, the reference frame changes from point to point. However, for the coordinate systems to be presented below, the reference frame depends only on the position of the particle. This is in contrast with the intrinsic coordinates, where the reference frame is a function of the position, as well as the path
文档格式:PDF 文档大小:108.11KB 文档页数:7
We will start by studying the motion of a particle. We think of particle as a body which has mass, but has negligible dimensions. Treating bodies as particles is, of course, an idealization which involves an approximation. This approximation may be perfectly acceptable in some situations and not adequate in some other cases. For instance, if we want to study the motion of planets it is common to consider each planet as a particle
文档格式:PPS 文档大小:2.7MB 文档页数:14
一、学会用焦利秤测量弹簧的倔强系数。 二、学会用集成霍耳传感器测量弹簧振子的振动周期,并计算弹簧的倔强系数
文档格式:DOC 文档大小:108.5KB 文档页数:5
一、填空(每空1分,共30分) 1.在并行机系统中,常用的静态互联网络有等。 2.在并行机系统中,常用的动态互联网络有和
首页上页540541542543544545546547下页末页
热门关键字
搜索一下,找到相关课件或文库资源 5590 个  
©2008-现在 cucdc.com 高等教育资讯网 版权所有