Concept Summery for FP FINAL 2012 spr.Chapter 1 【force and motion】(1) Concept1.particle: ideal object with mass, neglect size, shape, internal structure ...When the size of the object is much less than its moving range. It could be treat as a particle.2.description：equation of motion/position vector/displacement/Velocity (vector)/speed(scalar)/acceleration/instantaneous velocity/Angular velocity/acceleration –circular motion=>Common particle motions: Circular motion, projectile motion and general curvilinear motionmon force: Gravity/ Elastic force/ Friction/ Universal gravity4.Newton’s law of motion:[FIRST] Every object continues in its state of rest, or of uniform motion in a straight line, unless it is compelled to change that state by forces impressed upon it. [SECOND] The change of motion is proportional to the net force exert on the object, and occurs on the direction of the net force.[THIRD] If two objects interact, the force F12 exerted by object 1 on object 2 is equal in magnitude to and opposite in direction to the force F21 exerted by object 2 on object 1.5.Galilean relativity: You can not determine whether a frame is still or move at aconstant speed by mechanical experiment in this frame. This is called the Galilean relativity.(2) Calculation:1.v=dx/dt a=dv/dt 积分应用2.力学动力学过程分析Chapter 2【Conserved quantities and laws in motion】1.(1)Centroid: The center of mass of the system is called centroid.(2) Theorem of motion of centroid:No matter how distribution in mass of the body and how external froces are exerted on the body, the movement of centroid is like that all the mass as well as all the external force are focused at this point. (理解：炮弹飞行轨道上爆炸其质心运动的轨迹不变。

)2. (1)Theorem of momentum：during movement of a body, the increase of its momentum is equal to the impuse of the resultant external force(合外力).(2) Law of conservation of momentum If the resultant force of the system is zero, then the total momentum of the system is constant. (can be in just one direction) 3. Work: It is equal to the product of the displacement and the projection of the force in the direction of the displacement.Energy is a general measure of various forms of motion, is monotropic function of the state of the body, and reflects its ability of doing work.Theorem of kinetic energyThe change of kinetic energy of a mass point is equal to the work by the resultant force.4. conservative force:If the work by a force is independent on the motion path but only depends on the initial and end point of the body, we call such kind of force as conservative force.potential energy: The positon-dependent energy of a mass point in the conservative force field. It is a kind of underlying energy, and different from kinetic energy.5.kinetic energy theorem of system of mass pointsThe sum of works by all the external and internal forces on the system is equal to the increase of the total kinetic energy of the system.(书上例子：两个质点组成的系统)Work-energy theorem of system of mass points（？）When the system changes from state 1 to state 2, the increase of its mechanical energy is equal to the sum of works by external forces and nonconservative forces.w of conservation of mechanical energy: If there are only works by internalconservative forces on the system, or the sum of works by nonconservative forces and external forces is equal to zero, then we say that the kinetic energy and the potential energy of the bodies in the system can be transverted into each other but without changing the magnitude of the mechanical energy.w of conservation of energy：The sum of all forms of energy of a closedsystem remains constant no matters how the state of the system changes. The energy can only changes from one form into another form, or transfers from one body onto another body within the system.8.Angular momentum：Law of conservation of angular momentum：If the moment of force on the mass point is zero relative to a given point O, then the angular momentum of the mass point relative to point O remains constant.Chapter 3【Motion of rigid body and fluid】1. Rigid body: a rigid body is an idealization of a solid body of finite size in which deformation is neglected.（rigid body is a continuous mass distribution. The motion of each mass element obey the law of particle motion. The motion of the rigid body is the summation of each mass element.）2.Freedom degree: Number of independent variables to determine the position of an object, it indicates the degree of freedom.(1 particle->3 fd/2 particles->5 fd/3 or more->6 fd)3. moment:4. Law of fixed axis rotation of rigid body:(M为总外力矩，分析转动问题时利用安培右手定则判断方向，力矩方向均为沿着Z轴方向，便于分析)Rotational inertia:单个质点：J=mr^2（熟记几类特殊模型的转动惯量，并学会转动惯量的求解过程，十分重要）5. work and energy principle of fixed axis rotation6. law of angular momentum and the conservation law of angular momentum【angular momentum】（矢量：方向沿Z轴）Law of angular momentum of fixed axis rotation：Conservation law of angular momentumChapter 5【Kinetic theory of gases】1.description of thermal motion:State parameters1)Macroscopic quantity（宏观量）: Quantities that represents the macroscopic stateof a equilibrium state（PVT）2)Microscopic quantity(微观量):Quantities that represent the traits of certain particle in the system. （mass, radius, velocity, momentum, energy）Equilibrium stateA system that is in equilibrium experiences no changes when it is isolated from its surroundings.【Thermal equilibrium is dynamical equilibrium】Quasi-static processA quasi-static process often ensures that the system will go through a sequence of states that are infinitesimally close to equilibrium, in which case the process is typically reversible.State equation of ideal gas2. The basic traits of thermal motion：eternal motion and constant collision.3. *Accidental event:large amount of unpredictable events. Many times observations could lead to a distribution of these events, thus get the statistical regular.4.Micro-model of ideal gas（理想气体微观模型）：自由无规则运动的弹性球。