1、This gravitational force is called weight.（重力）10、 Near the Ethers surface, the gravitational force on each kg is about 10 N:the gravitational field strength重力场强度 is 10 N kg-1. This is represented by the symbol g.（g的概念）11、 Work功 is done whenever a force makes something move.12、 Things have energy 能if
2、 they can do work。工作的物体都有能量。13、 Energy exists in different forms:（能量存在形势） Kinetic energy，Potential energy，Internal energy，Heat （thermal energy），Radiant energy14、 Energy changes能量守恒定律According to the law of conservation of energy: Energy cannot be made or destroyed, but it can be changed fromone form
3、 to another. 能量的变化。根据能量守恒定律：能量不能被破坏，但它可以从一种形式转化为另一种。15、 计算势能：work done = force distance moved = mg h So potential energy势能 = mgh For example, if a 2 kg stone is 5 m above the ground, and g is 10 N kg-1, then the stones PE = 2105 = 100 J.16、 计算动能： kinetic energy = 1/2mv2 For example, if a 2 kg stone
4、has a speed of 10 m s-1, it KE = 1/22102 = 100 J.17、 Everything is made from about 100 substances called elements.元素18、 Kelvin 开尔文scaleThis has the same sized degree as the Celsius scale, but its zero is absolute zero （-273 C）19、 多选Heat can be transferred by conduction, convection, and radiation, as
5、 well as by evaporation. 热量可以传送通过传导，对流，辐射，以及由蒸发。20、 The region around a magnet where magnetic forces act is sometimes called a magnetic field.磁场21、 If one end of a bar magnet is moved into a coil, as below, an EMF （voltage） is generated in the coil. This effect is called electromagnetic induction.电磁
6、感应22、 （）The EMF makes a current flow in the circuit. 电动势使电路中的电流流动。23、 多选The induced EMF （and the current） is increased if :the magnet is moved faster ,there are more turns on the coil, a magnet giving a stronger field is used.电动势增加条件24、 Transverse wave横向波 The oscillations are at right-angles to the
7、direction of travel25、 Longitudinal wave 纵向波The oscillations are in line with the direction of travel, so that a compress （squash） is followed by a rarefaction （stretch）, and so on:26、 多选Wave features：Amplitude，Frequency，Wavelength，Speed27、 speed = frequency wavelength速度=频率波长 For example, if the fre
8、quency is 5 Hz and the wavelength is 2 m,then the wave speed is 10 m s-128、 多选Wave in a ripple tank：Reflection，Refraction，Diffraction，Interference29、 waves bend around the edges of a narrow gap. This is called diffraction.衍射30、 Sound waves are longitudinal声波是长纵波31、 Uncertainty误差: systematic uncertai
9、nties系统误差（these occur because of some inaccuracy in the measuring system or in how it is being used）, random uncertainties随机误差（these can occur because there is a limit to the sensitivity of the measuring instrument or to how accurately you can read it）32、 For example, say you measure a current I, a
10、voltage V, and calculate a resistance R using the equation R=V/I. If there is a 3% uncertainty in V and a 4% uncertainty in I, then there is a 7% uncertainty in your calculated value of R.例如，你测量到电流I，和电压V，计算电阻R，使用公式R=V/I，如果V有3%的误差，I有4%的误差，那么你计算结果R就有7%的误差。33、 A2=AA, the % uncertainty in A2 is twice th
11、at in A.34、 In this equation, m and c are constants常数, as shown below. Y and x are variables because they can take different values. X is the independent variable自变量, y is the dependent variable因变量: its value depends on the value of X.35、 （/选择）Labelling graph axes:标号图轴 The scales on the graphs axes
12、are pure , unitless numbers and not voltages or currents.36、 Vectors are quantities which have both magnitude （size） and direction. Examples include displacement and force.向量是有大小和方向的量，例如位移和力。37、 （）Any vector can be resolved into components.任何矢量都能被分解成分力38、 There are two types of motion: translational
13、 and rotational .平动和转动39、 A pair of equal but opposite forces is called a couple.力偶40、 The total moment of a couple is called a torque.力偶距41、 Newton called this resistance to change in motion inertia.惯性42、 The quantity forcetime is called an impulse.冲量43、 When the objects velocity is V ,its KE=1/2mv
14、244、 Elastic collision :An elastic collision is one in which the total kinetic energy of the colliding objects remains constant弹性碰撞是在其中的物体碰撞的总动能不变45、 Inelastic collision:In an inelastic collision, kinetic energy is converted into head在非弹性碰撞中，动能转化为首要的。46、 Without friction, no forward force would be n
15、eeded to maintain a steady velocity, so no work would be done. 无摩擦，没有前进的动力，将需要维持一个稳定的速度，所以没有工作就完成了。47、 If point P moves to P, then the angle is called the Angular displacement角位移48、 The rate of rotation can be measured either as an angular velocity or as a frequency. 旋转率可以作为角速度或频率。49、 （）To produce c
16、entripetal acceleration, a centripetal force is need. 产生向心加速度，向心力是需50、 Centripetal force is not produced by circular motion. It is the force needed for circular motion. 向心力不是由圆周运动所产生的。它是由圆周运动所需的力产生。51、 All masses attract each other with a gravitational force.（万有引力）一切物质由于引力相互吸引。52、 If a mass feels a
17、gravitational force, then it is in a gravitational field.（万有引力场）如果质量有引力，那么他在万有引力场53、 Work must be done to move a mass against a gravitational field. 工作必须做到对引力场的大规模行动。54、 （Arial 字体）Like energy ，gravitational potential is a scalar. 像能量，引力势是一个标量。55、 At infinity, the gravitational potential is zero. 无穷大
18、，引力势为零。56、 Elsewhere, the gravitational potential is negative. 别处，引力势为负。57、 The speed of the waves through space ，called the speed of light波的速度通过空间，称为光的速度58、 The waves above are in phase and reinforce each other. This is called constructive interference.干涉相长59、 The waves above have a phase differenc
19、e of 1/2 cycle （180） and cancel each other. This is called destructive interference.干涉相消60、 Double-slit diffraction双缝衍射 Single-slit diffraction单缝衍射 convex lens凸透镜 concave lens 凹透镜 optical center光学中心 focal length 焦距61、 The spreading of light from a slit is an example of diffraction. 传播的光从一个狭缝的衍射为例62、
20、 The waves produced are known as stationary waves驻波. At nodes波节 the amplitude of the oscillation is always zero. At antinodes波腹, it is always a maximum.。产生的波被称为驻波。在节点的振荡的幅度是零。在波腹，它始终是一个最大的。63、 Sound waves are longitudinal.光波是纵波64、 Where the end of a pipe（管） is open, there is an antinode.波腹65、 Where
21、the end of a pipe is close, there is a node波节66、 The image in a plane mirror is known as a virtual image 虚像because no rays pass throught it.67、 The diameter直径 of the objective lens 物镜is called its aperture.光圈1、 In a fluid: Pressure acts in all directions. The force produced is always at right-angles
22、 to the surface under pressure .Pressure increases with depth. 在液体中的：压力作用在所有方向。产生的力总是垂直受压力的表面。压力随深度增加而增加。2、 翻译，选择：When balanced forces act on something, its acceleration is zero. This means that it is either stationary or moving at a steady velocity.（steady speed in a straight line） 当平衡力作用在物体上，它的加速度
23、是零。这意味着无论是固定的或移动的在一个稳定的速度。（在一条直线上稳定的速率）。3、 According to the kinetic theory, matter is made up of tiny, randomly moving particles. Each particle may be a single atom, a group of atoms called a molecule, or an ion. The three normal phase of a matter are solid, liquid, and gas.根据动力学理论，物质是由微小的、随机移动的粒子组成
24、。每个粒子都可能是一个单独的原子，很多原子就被称为分子或离子。物质的三种正常状态是固体液体和气体。4、 The heat required to change a liquid into a gas （or a solid into a liquid） is called latent heat. When water evaporates on the back of your hand, it takes the laten heat it needs from your hand. That is why there is a cooling effect。改变液体变成气体所需要的热能被
25、称为潜热。当水在你的手背蒸发时候，它从你的手背带走他需要的潜热，这就是为什么有冷却作用。5、 In an optical fiber, light entering one end of the glass or plastic fiber is totally internally reflected until it comes out of the other.在光纤中，当光进入玻璃或塑料光纤的一端是完全内部反射的，直到光从另一端出来。6、 Numbers written using powers of 10 are in scientific notation or standard
26、form. This is also used for small numbers. For example, 0.002 can be written as 210-3.数字可以用科学计数法或标准形式写成10的幂形式，它也可以记录小的数字，例如0.002就可以写成210-37、 As a general guideline, a calculate result should have no more significant figures than any of the measurements used in the calculation.作为一般准则，计算结果不会比计算中使用的测量有
27、效数字更重要。8、 If an object is in equilibrium, the sum of the clockwise moment about any axis is equal to the sum of the anticlockwise moments.如果一个物体在平衡状态，对任何的轴顺时针力矩之和都等于所有的逆时针力矩之和。9、 If there is no resultant force acting: a stationary object will stay at rest, a moving object will maintain a constant ve
28、locity （a steady speed in a straight line）.如果没有合力作用：一个静止的物体会保持静止；一个运动的物体会保持恒定速度运动（在一条直线上的恒定速率） 牛顿第一定律10、 The rate of change of momentum of an object is proportional to the resultant force acting.一个物体的动量的变化量和它所受的合力成正比。牛顿第2定律11、 If A is exerting a force on B, then B is exerting an equal but opposite f
29、orce on A.如果A发出一个力作用在B上，那么B也发出同样但是相反的力作用在A上。To every action, there is an equal but opposite reaction.对于每一次作用，都会有一个相等但是方向相反的反作用力。牛顿第三定律12、 Law of conservation of momentum：when the object in a system interact ,their total momentum remains constant, provided that there is no external force on the system. 动量守恒定律,当一个物体在一个不提供任何其他外力作用的系统中，他们的总动量是保持不变的。13、 When something accelerates, its velocity changes. As velocity is a vector, this can mean a change in speed or direction （or both）. Centripetal acceleration
