Lecture D33: Forced Vibration Fosinwt m Spring Force Fs =-kx, k>0 Dashpot Fd =-ci, c>0 Forcing Fext Fo sin wt Newton's Second Law (mix =CF) mx+cx+kx= Fo sin wt =k/m,=c/(2mwn)

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

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

When the only force acting on a particle is always directed to- wards a fixed point, the motion is called central force motion. This type of motion is particularly relevant when studying the orbital movement of planets and satellites. The laws which gov- ern this motion were first postulated by Kepler and deduced from observation. In this lecture, we will see that these laws are a con- sequence of Newton's second law. An understanding of central

In this lecture, we consider the problem of a body in which the mass of the body changes during the motion, that is, m is a function of t, i.e. m(t). Although there are many cases for which this particular model is applicable, one of obvious importance to us are rockets. We shall see that a significant fraction of the mass of a rocket is the fuel, which is expelled during flight at a high velocity and thus, provides the propulsive force for the rocket

In this lecture, we will consider how to transfer from one orbit, or trajectory, to another. One of the assumptions that we shall make is that the velocity changes of the spacecraft, due to the propulsive effects, occur instantaneously. Although it obviously takes some time for the spacecraft to accelerate to the velocity of the new orbit, this assumption is reasonable when the burn time of the rocket is much smaller than the period of the orbit. In such cases, the Av required to do the maneuver is simply the difference between the

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

《工程热力学》课程教学资源（试卷习题）工程热力学套题库（共二十套，无答案）

能源与节能技术课程教材建设 一、学科发展现状与课题立项背景 二、课题研究内容与执行计划 三、教育创新特色与应用价值 四、现有工作基础 五、特色演示

工程热力学的研究内容： ❖ 1. 热力学基本定律，包括基本概念及定义与热力学第一定律、熵与热力学第二定律等。 ❖ 2. 工质的热力性质，包括一般热力学关系，理想气体、水蒸汽、理想气体混合物、湿空气的热力性质的计算及图表的应用。 ❖ 3. 热力过程及热力循环，包括典型热力过程的分析以及气体与蒸汽的流动、气体压缩、蒸汽动力循环、气体动力循环和制冷循环的分析计算 ❖ 4. 化学热力学基础。 本课件章节内容：绪论 第一章——基本概念 第二章——理想气体的性质 第三章——热力学第一定律 第四章——理想气体的热力过程及气体压缩 第五章——热力学第二定律 第六章——热力学微分关系式及实际气体性质 第七章——水蒸气 第八章——湿空气 第九章——气体和蒸汽的流动 第十章——动力循环 第十一章——致冷循环 第十二章——化学热力学基础