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

In this lecture, we will revisit the application of Newton's second law to a system of particles and derive some useful relationships expressing the conservation of angular momentum. Center of Mass Consider a system made up of n particles. A typical particle, i, has mass mi, and, at the instant considered, occupies the position Ti relative to a frame xyz. We can then define the center of mass, G, as the point

Non-Inertial Reference Frame Gravitational attraction The Law of Universal Attraction was already introduced in lecture D1. The law postulates that the force of attraction between any two particles, of masses M and m, respectively, has a magnitude, F, given by F= (1) where r is the distance between the two particles, and G is the universal constant of gravitation. The value of G is empirically determined to be

In the previous lectures we have described particle motion as it would be seen by an observer standing still at a fixed origin. This type of motion is called absolute motion. In many situations of practical interest, we find ourselves forced to describe the motion of bodies while we are simultaneously moving with respect to a more basic reference. There are many examples were such situations occur. The absolute motion of a passenger inside an aircraft is best

We have seen that the work done by a force F on a particle is given by dw =. dr. If the work done by F, when the particle moves from any position TI to any position T2, can be expressed as, W12=fdr=-(V(r2)-V(1)=V-v2, (1) then we say that the force is conservative. In the above expression, the scalar

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

I. Choose the Correct Answer 1. An object is moving along the x axis with position as a function of time given by x=x(). Point is at x 0. The object is definitely moving toward O when

第一节动脉粥样硬化( atherosclerosis,As) 第二节冠状动脉性心脏病(coronary heart disease) 第三节高血压 hypertension 第四节风湿病( rheumatism)

1. Carbohydrates are aldehyde or ketone compounds with multiple hydroxyl groups or substances that can yield such compounds on hydrolysis(p. 293) 1.1 Carbohydrates are the most abundant biomolecules on earth and have multiple roles in all forms of life. 1.1.1 Carbohydrates serve as energy stores (e.g., starch in plants, glycogen in animals), fuels (e.g., glucose), and metabolic intermediates (e.., ATP, many coenzymes)

Introduction \Breast cancer is one of the best studied human tumors, but it remains poorly understood” “ As in all medical endeavors, the practitioner should, whenever possible, use the results of scientific studies to quide clinical decision\