📚 Year 9 OCR Physics: Core Knowledge Checklist | 核心知识点梳理
Welcome to the core knowledge checklist for Year 9 OCR Physics. This guide breaks down the most important concepts you need to understand, from energy transfers to electric circuits and waves. Each section gives you a clear explanation of the key physics ideas, paired with everyday examples, so you can build a solid foundation for your GCSE studies.
欢迎阅读九年级 OCR 物理核心知识点梳理。本指南将你需要掌握的最重要概念分解讲解，涵盖能量转移、电路以及波等内容。每个部分都清晰解释了关键的物理概念，并配以生活实例，帮助你为 GCSE 学习打下坚实基础。
1. Energy Stores and Transfers | 能量储存与转移
Energy is never created or destroyed. Instead, it moves between different 'stores' and can be transferred from one place to another. The main energy stores include kinetic, gravitational potential, elastic potential, thermal, chemical, magnetic, electrostatic, and nuclear. Energy transfers happen through mechanical work, electrical work, heating, and radiation.
能量既不会凭空产生，也不会凭空消失。它会在不同的“储存库”之间移动，并从一个地方转移到另一个地方。主要的能量储存形式包括动能、重力势能、弹性势能、热能（内能）、化学能、磁能、静电势能和核能。能量转移通过做机械功、电功、加热和辐射等方式发生。
A moving car has kinetic energy. When it brakes, friction transfers this kinetic energy to the thermal energy store of the brakes and surroundings, raising the temperature.
行驶中的汽车具有动能。当它刹车时，摩擦力将动能转移到刹车片和周围环境的热能储存中，导致温度升高。
Gravitational potential energy depends on an object' re m is mass, g is gravitational field strength (about 10 N/kg on Earth), and h is height.
重力势能取决于物体的高度。物体位置越高，储存的能量就越多。公式为 GPE = m × g × h，其中 m 是质量，g 是重力场强度（在地球上约为 10 N/kg），h 是高度。
GPE = m × g × h
Elastic potential energy is stored in stretched or compressed springs and rubber bands. The more an object is deformed, the more energy is stored, as long as the elastic limit is not exceeded.
弹性势能储存在被拉伸或压缩的弹簧和橡皮筋中。只要不超过弹性限度，物体形变越大，储存的能量就越多。
ergy. The formula is KE = ½ × m × v², so doubling the speed quadruples the kinetic energy.
动能取决于质量和速度。重型卡车和高速跑车都可以具有很大的动能。公式为 KE = ½ × m × v²，因此速度加倍会使动能变为原来的四倍。
KE = ½ × m × v²
Thermal energy stores represent the total kinetic and potential energy of particles in a substance. Higher temperature means particles move faster, so the thermal energy store increases.
热能（内能）储存代表物质内部粒子的总动能和势能。温度越高意味着粒子运动越快，因此热能储存量增加。
Chemical energy is stored in fuels, food, and batteries. It is released during chemical reactions, such as burning or digestion.
化学能储存在燃料、食物和电池中。它在化学反应（如燃烧或消化）过程中被释放出来。
When energy is transferred, the total amount of energy in the universe remains constant. This is the principle of conservation of energy.
当能量发生转移时，宇宙中的总能量保持不变。这就是能量守恒定律。
2. Kinetic Theory and Particle Model | 分子运动论与粒子模型
The particle model explains the properties of solids, liquids, and gases. All matter is made of tiny particles that are constantly moving. In solids, particles vibrate in fixed positions. In liquids, particles can slide past each other. In gases, particles move rapidly in all directions with large spaces between them.
粒子模型解释了固体、液体和气体的性质。所有物质都由不断运动的微小粒子组成。在固体中，粒子在固定位置上振动。在液体中，粒子可以相互滑动。在气体中，粒子快速地向各个方向运动，彼此间有较大的间隙。
Temperature is a measure of the average kinetic energy of the particles. When you heat a substance, you increase the kinetic energy of its particles, making them move faster.
温度是粒子平均动能的量度。当你加热一种物质时，会增加其粒子的动能，使它们运动得更快。
Brownian motion provides evidence for the particle model. Pollen grains in water appear to jiggle randomly under a microscope because they are being bombarded by invisible, moving water particles.
布朗运动为粒子模型提供了证据。在显微镜下，水中的花粉颗粒看起来在随机抖动，因为它们受到了看不见的运动的水分子的撞击。
Diffusion is the spreading out of particles from a region of high concentration to a region of low concentration. It happens faster in gases than in liquids because gas particles move more quickly and have more space.
扩散是粒子从高浓度区域向低浓度区域散开的过程。气体中的扩散比液体中快，因为气体粒子运动更快，且间隙更大。
State changes, like melting and boiling, involve energy transfers without a change in temperature. The energy goes into breaking bonds between particles rather than raising kinetic energy.
物态变化（如熔化和沸腾）涉及能量转移，但温度不发生变化。能量用于打破粒子之间的键，而不是增加动能。
3. Density and States of Matter | 密度与物质状态
ensity, m is mass, and V is volume. The SI unit is kg/m³, but g/cm³ is also commonly used.
密度是物质单位体积的质量。它反映了粒子的紧密程度。公式为 ρ = m ÷ V，其中 ρ 是密度，m 是质量，V 是体积。国际单位是 kg/m³，但也常用 g/cm³。
ρ = m ÷ V
Solids are generally the most dense state because particles are packed closely together. Gases are the least dense because particles are far apart. An exception is water: ice is less dense than liquid water, which is why ice floats.
固体通常是密度最高的物态，因为粒子紧密堆积在一起。气体的密度最低，因为粒子相距很远。水是一个例外：冰的密度小于液态水，这就是冰能浮在水面上的原因。
To find the density of an irregular solid, you can measure its mass using a balance and its volume by the displacement of water in a measuring cylinder. Then divide mass by volume.
要测量不规则固体的密度，你可以用天平测量其质量，用排水法在量筒中测量其体积。然后用质量除以体积。
Heating a substance usually causes it to expand and its density to decrease, because the particles gain kinetic energy and move further apart. This is why hot air rises.
加热物质通常会导致其膨胀，密度减小，因为粒子获得动能并相互远离。这就是热空气上升的原因。
4. Forces and Motion | 力与运动
A force is a push or a pull that can change the speed, direction, or shape of an object. Forces are measured in newtons (N). Contact forces include friction, tension, and normal reaction. Non-contact forces include gravity, magnetic, and electrostatic forces.
力是能改变物体速度、方向或形状的推或拉的作用。力的单位是牛顿 (N)。接触力包括摩擦力、张力和法向反作用力。非接触力包括重力、磁力和静电力。
nce ÷ total time. The unit is m/s. If an object covers 100 m in 20 s, its average speed is 5 m/s.
速率是单位时间内通过的路程。平均速率 = 总路程 ÷ 总时间。单位是 m/s。如果一个物体在 20 s 内移动了 100 m，其平均速率为 5 m/s。
v = s ÷ t
Forces can be represented by arrows on a free-body diagram. The length of the arrow shows the magnitude, and the direction shows the direction of the force. If the forces are balanced, the object stays at rest or moves at constant velocity. If they are unbalanced, the object accelerates or decelerates.
力可以在受力分析图上用箭头表示。箭头的长度表示力的大小，方向表示力的方向。如果力是平衡的，物体要么保持静止，要么做匀速直线运动。如果力不平衡，物体会加速或减速。
Friction is a force that opposes motion between two surfaces. Air resistance is a type of friction that acts on objects moving through air. Streamlining reduces air resistance.
摩擦力是阻碍两个表面之间相对运动的力。空气阻力是作用于在空气中运动的物体的一种摩擦力。流线型设计可以减小空气阻力。
ional field strength. Weight = mass × g. On Earth, g ≈ 10 N/kg, so a 50 kg person weighs about 500 N.
质量是物体所含物质的多少，不随位置改变。重量是物体受到的重力，取决于重力场强度。重量 = 质量 × g。在地球上，g ≈ 10 N/kg，因此一个 50 kg 的人重量约为 500 N。
W = m × g
Hooke' not exceeded. The formula is F = k × x, where k is the spring constant and x is extension.
胡克定律指出，在不超过弹性限度的条件下，弹簧的伸长量与所施加的力成正比。公式为 F = k × x，其中 k 是弹簧常数，x 是伸长量。
5. Pressure in Fluids | 流体压强
orce on a smaller area produces higher pressure. This is why sharp knives cut more easily.
压强是作用在单位面积上的力。单位是帕斯卡 (Pa)，1 Pa = 1 N/m²。在较小面积上施加较大的力会产生较高的压强。这就是为什么锋利的刀更容易切割。
P = F ÷ A
In a liquid, pressure increases with depth because of the weight of the liquid above. Pressure in a liquid acts equally in all directions and explains why dam walls are thicker at the bottom.
在液体中，压强随深度增加而增大，这是因为上方液体的重量。液体中的压强在各个方向上均等作用，这解释了为什么水坝的底部墙壁更厚。
Atmospheric pressure is caused by the weight of air above us. It decreases with altitude and can be measured with a barometer. At sea level, standard atmospheric pressure is about 101,000 Pa.
大气压是由我们上方空气的重量造成的。它随海拔升高而降低，可以用气压计测量。在海平面上，标准大气压约为 101,000 Pa。
An object submerged in a fluid experiences an upthrust equal to the weight of the fluid displaced. If the upthrust is equal to the object's weight, it floats. This is known as Archimedes' principle.
浸没在流体中的物体会受到一个向上的浮力，大小等于它排开的流体的重量。如果浮力等于物体的重量，物体就会漂浮。这就是阿基米德原理。
6. Electric Circuits and Current | 电路与电流
Electric current is the flow of electric charge. In metal wires, the charge carriers are electrons. Current is measured in amperes (A) using an ammeter connected in series. For a current to flow, you need a complete circuit and a source of potential difference (voltage).
电流是电荷的定向流动。在金属导线中，电荷的载体是电子。电流的单位是安培 (A)，使用串联在电路中的电流表测量。要让电流流动，需要一个完整的电路和电势差（电压）源。
a is I = Q ÷ t, where I is current, Q is charge in coulombs (C), and t is time in seconds.
电流是电荷流动的速率。公式为 I = Q ÷ t，其中 I 是电流，Q 是电荷量（库仑），t 是时间（秒）。
I = Q ÷ t
In a series circuit, there is only one loop, so the current is the same everywhere. If you add more bulbs in series, they share the voltage and become dimmer.
在串联电路中，只有一个回路，因此各处电流相同。如果你在串联电路中增加更多灯泡，它们会分担电压，因而变得更暗。
In a parallel circuit, the current splits at junctions. The total current from the battery equals the sum of the currents in the branches. Each branch receives the full battery voltage, so bulbs in parallel shine brighter.
在并联电路中，电流在节点处分开。电池提供的总电流等于各支路电流之和。每个支路都获得完整的电池电压，因此并联的灯泡更亮。
Conventional current flows from the positive to the negative terminal, even though electrons actually move from negative to positive.
传统电流方向是从正极流向负极，尽管实际上电子是从负极流向正极。
7. Voltage, Resistance and Ohm's Law | 电压、电阻与欧姆定律
Potential difference (voltage) is the energy transferred per unit charge. It is measured in volts (V) using a voltmeter connected in parallel. 1 volt means 1 joule of energy is transferred per coulomb of charge.
电势差（电压）是每单位电荷转移的能量。单位是伏特 (V)，使用并联的电压表测量。1 伏特意味着每库仑电荷转移 1 焦耳的能量。
higher resistance than a short, thick wire. Resistance can be calculated using R = V ÷ I.
电阻阻挡电流的流动。单位是欧姆 (Ω)。又长又细的导线比又短又粗的导线电阻更大。电阻可以用 R = V ÷ I 计算。
R = V ÷ I
Ohm's Law states that the current through a conductor is directly proportional to the voltage across it, provided the temperature remains constant. A component that follows this rule is called an ohmic conductor, like a metal wire at constant temperature.
欧姆定律指出，在温度保持不变的条件下，通过导体的电流与其两端的电压成正比。遵循这一规律的元件称为欧姆导体，例如恒温下的金属导线。
The resistance of some components changes. A filament lamp gets hotter as current increases, causing its resistance to increase. A diode only allows current to flow in one direction and has very high resistance in the reverse direction.
某些元件的电阻会发生变化。随着电流增大，白炽灯的温度升高，导致其电阻增大。二极管只允许电流单向流动，反向时电阻极高。
A thermistor has a resistance that decreases as temperature increases. A light-dependent resistor (LDR) has a resistance that decreases as light intensity increases. These are used in sensors.
热敏电阻的阻值随温度升高而减小。光敏电阻 (LDR) 的阻值随光照强度增大而减小。这些元件常用于传感器中。
8. Magnetism and Electromagnets | 磁与电磁铁
Magnets have two poles: north and south. Like poles repel, unlike poles attract. The magnetic field is the region around a magnet where magnetic materials experience a force. Field lines run from north to south and are closer together where the field is stronger.
磁铁有两个磁极：北极 (N) 和南极 (S)。同名磁极相互排斥，异名磁极相互吸引。磁场是磁铁周围磁性材料会受到作用力的区域。磁感线从北极指向南极，在磁场较强的地方线条更密集。
The Earth has a magnetic field with its magnetic south pole near the geographic North Pole. A compass needle is a small bar magnet that aligns with the Earth's field, pointing north.
地球具有磁场，其磁南极靠近地理北极。指南针的指针是一个小条形磁铁，它沿地球磁场方向排列，指向北方。
An electromagnet is a coil of wire (solenoid) with an iron core. When current flows, a magnetic field is produced. The strength can be increased by increasing the current, adding more turns to the coil, or using a soft iron core.
电磁铁是一个带有铁芯的线圈（螺线管）。当电流流过时，会产生磁场。增大电流、增加线圈匝数或使用软铁芯都可以增强其磁场强度。
Electromagnets are used in relays, electric bells, and scrap-metal cranes. Unlike permanent magnets, they can be turned on and off.
电磁铁用于继电器、电铃和废金属起重机。与永磁体不同，电磁铁可以通断控制。
When a current-carrying wire is placed in a magnetic field, it experiences a force. This is the motor effect and is used in loudspeakers and electric motors.
当通电导线置于磁场中时，会受到力的作用。这就是电动机效应，利用此原理制成了扬声器和电动机。
9. Waves: Sound and Light | 波：声与光
Waves transfer energy without transferring matter. They can be transverse (oscillations perpendicular to wave travel, like light) or longitudinal (oscillations parallel to wave travel, like sound).
波传递能量而不传递物质。波可以是横波（振动方向与波的传播方向垂直，如光）或纵波（振动方向与波的传播方向平行，如声音）。
The amplitude is the maximum displacement from the rest position. The wavelength is the distance between two consecutive crests or compressions. Frequency is the number of complete waves passing a point per second, measured in hertz (Hz).
振幅是质点离开平衡位置的最大位移。波长是两个相邻波峰或压缩区之间的距离。频率是每秒通过某点的完整波的个数，单位是赫兹 (Hz)。
v = f × λ
The wave speed equals frequency multiplied by wavelength. Sound travels at about 330 m/s in air but faster in solids and liquids.
波速等于频率乘以波长。声音在空气中的传播速度约为 330 m/s，但在固体和液体中传播得更快。
Sound is a longitudinal wave caused by vibrating objects. It cannot travel through a vacuum because there are no particles to vibrate. Humans hear sounds between about 20 Hz and 20,000 Hz. Ultrasound has frequencies above this range.
声音是由振动体产生的纵波。它不能在真空中传播，因为没有介质粒子振动。人耳可以听到约 20 Hz 到 20,000 Hz 的声音。超声波指频率超过此范围的高频声波。
Light is a transverse electromagnetic wave. It travels at a speed of 300,000,000 m/s in a vacuum. Light can travel through empty space, unlike sound.
光是一种横波，属于电磁波。它在真空中的速度是 300,000,000 m/s（3×10⁸ m/s）。与声音不同，光可以在真空中传播。
When light hits a plane mirror, the angle of incidence equals the angle of reflection. This is called the law of reflection. Refraction happens when light passes from one medium to another, changing speed and direction unless it enters along the normal.
当光照射到平面镜上时，入射角等于反射角。这被称为反射定律。当光从一种介质进入另一种介质时，会发生折射，速度和方向都会改变，除非光是沿法线方向入射。
10. Static Electricity and Atomic Structure | 静电与原子结构
All substances are made of atoms. An atom consists of a tiny, positively charged nucleus containing protons and neutrons, surrounded by electrons in orbits. Protons have a positive charge, electrons are negative, and neutrons are neutral.
所有物质都是由原子构成的。原子由一个极小的带正电的原子核（包含质子和中子）以及在轨道上运动的电子组成。质子带正电，电子带负电，中子不带电。
An uncharged atom has equal numbers of protons and electrons. If electrons are added or removed, the atom becomes an ion. An object becomes statically charged when electrons are transferred from one material to another by friction.
不带电的原子中质子和电子数目相同。如果得到或失去电子，原子就变成了离子。当电子通过摩擦从一种材料转移到另一种材料时，物体就会带上静电。
Rubbing a polythene rod with a cloth transfers electrons to the rod, making it negatively charged. Rubbing a perspex rod with a cloth removes electrons, leaving it positively charged. Like charges repel; opposite charges attract.
用布摩擦聚乙烯棒，电子转移到棒上，聚乙烯棒带负电。用布摩擦有机玻璃棒，电子从棒上移走，有机玻璃棒带正电。同种电荷相互排斥，异种电荷相互吸引。
Static electricity can cause sparks, which may be dangerous near flammable gases. Earthing and bonding are used to safely discharge static build-up, such as in aircraft refuelling.
静电可能产生火花，在易燃气体附近很危险。在飞机加油等操作中，会使用接地和等电位联结来安全释放积聚的静电。
Electrostatic forces are non-contact forces between charged objects. Electric fields surround charged objects and can be represented by field lines pointing away from positive charges and toward negative charges.
静电力是带电物体之间的非接触力。电场包围带电物体，可以用电场线表示，电场线从正电荷指向负电荷。
11. The Solar System and Beyond | 太阳系与宇宙
The Solar System consists of the Sun, eight planets, their moons, and smaller bodies like asteroids and comets. The planets in order from the Sun are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune.
太阳系由太阳、八大行星、它们的卫星以及小行星和彗星等较小天体组成。按照离太阳由近及远的顺序，行星依次是水星、金星、地球、火星、木星、土星、天王星和海王星。
The Earth orbits the Sun once every 365.25 days (one year). The Moon orbits the Earth approximately every 28 days. Seasons occur because the Earth's axis is tilted by 23.5°, so different hemispheres receive more direct sunlight at different times of the year.
地球绕太阳公转一周约需 365.25 天（一年）。月球约每 28 天绕地球运行一周。四季的成因是地球自转轴倾斜了 23.5°，因此不同时间南北半球接收到的太阳直射光量不同。
The Moon reflects sunlight and appears to change shape (phases) over a month because we see different amounts of its illuminated half. A lunar eclipse occurs when Earth blocks sunlight from reaching the Moon.
月球反射太阳光，在一个月内它看起来形状（月相）会发生变化，因为我们能看到的被太阳照亮的部分在变化。当地球挡住太阳射向月球的光时，就会发生月食。
Stars are massive balls of gas that emit light and heat due to nuclear fusion. The Sun is just one star among billions in the Milky Way galaxy. A galaxy is a huge collection of stars, gas, and dust held together by gravity.
恒星是巨大的气态球体，通过核聚变发出光和热。太阳只是银河系数十亿颗恒星中的一颗。星系是由引力束缚在一起的恒星、气体和尘埃的巨大集合体。
The universe contains billions of galaxies and is still expanding. The Big Bang theory suggests that the universe began from an extremely hot and dense point about 13.8 billion years ago.
宇宙包含数十亿个星系，并且仍在膨胀。大爆炸理论认为，宇宙约在 138 亿年前从一个极热、极密的奇点开始膨胀形成的。
Published by TutorHao | Physics Revision Series | aleveler.com
更多咨询请联系16621398022（同微信）
或截图后用「扫一扫 → 相册」选择本图