📚 Year 8 CAIE Physics: Key Terms Memorisation Guide | Year 8 CAIE 物理：关键术语速记指南
Mastering physics vocabulary is the first step toward understanding how the world works. In this guide, we break down the essential CAIE Year 8 terms with simple explanations and clever memory tricks to help you learn them quickly and effectively.
掌握物理词汇是理解世界运行的第一步。本指南将 CAIE Year 8 的核心术语进行拆解，提供简单解释和巧妙记忆技巧，助你快速高效地学习。
1. Motion and Speed | 运动与速度
ated as distance divided by time. Use the formula triangle: cover up the quantity you need – speed (s), distance (d), time (t) – where distance = speed × time. The mnemonic "SPEeD = Distance over Time" uses the first letters.
速率表示物体运动的快慢，不考虑方向。计算公式是距离除以时间。记住公式三角形：遮住你需要的量——速率(s)、距离(d)、时间(t)——距离 = 速率 × 时间。助记口诀："SPEeD = Distance over Time" 取首字母。
Velocity is speed in a particular direction. It is a vector quantity, meaning it has both magnitude and direction. To remember the difference, think: "Velocity has a Vector, speed is just a Scalar."
速度是带有方向的速率。它是矢量，既有大小又有方向。记住区别的口诀："Velocity 有 Vector（矢量），Speed 只是 Scalar（标量）。"
Acceleration is the rate of change of velocity. If an object speeds up, slows down or changes direction, it accelerates. Visualise a car's "accelerator pedal" – it changes velocity. The unit is m/s².
加速度是速度变化的快慢。物体加速、减速或改变方向均意味着有加速度。联想汽车的"油门踏板(accelerator)"——它改变速度。单位是 m/s²。
2. Forces and their Effects | 力及其作用效果
A force is a push or a pull that can change an object's shape, speed or direction. Forces are measured in newtons (N). To remember the unit, imagine Sir Isaac Newton sitting under an apple tree – the apple's weight exerted a force of about 1 N.
力是能改变物体形状、速率或方向的推或拉。力的单位是牛顿(N)。助记：想象牛顿坐在苹果树下——一个苹果的重量大约施加 1 N 的力。
Friction is a force that opposes motion between two surfaces in contact. It can be helpful (e.g., walking) or unhelpful (e.g., engine wear). Think: "Friction fights motion" – all words start with F.
摩擦力是阻碍两接触表面相对运动的力。它可以有益（如走路）或有害（如引擎磨损）。助记："Friction fights motion"（摩擦力对抗运动），两个词都以 F 开头。
Balanced forces result in no change in motion (constant velocity or stationary), while unbalanced forces cause acceleration. Picture a tug-of-war: if both sides pull equally, forces are balanced; if one side pulls harder, forces are unbalanced and movement occurs.
平衡力导致运动状态不变（匀速或静止），非平衡力导致加速度。想象拔河：若双方拉力相等，力平衡；若一方更用力，力不平衡，产生运动。
3. Mass, Weight and Gravity | 质量、重量与重力
atter in an object, measured in kilograms (kg). It does not change with location. Think of "mass" as "massive stuff" ons (N). Formula: weight = mass × gravitational field strength (g). On Earth, g ≈ 10 N/kg.
质量是物体所含物质的多少，单位是千克(kg)，不随位置改变。记"mass"就是"大量物质"。重量是重力对物体的作用力，单位是牛顿(N)。公式：重量 = 质量 × 重力场强度(g)。在地球上 g ≈ 10 N/kg。
Gravity is the force of attraction between all masses. The gravitational field strength on the Moon is about 1.6 N/kg, so objects weigh less there. Remember: "Weight depends on Where you are; Mass stays Master."
重力是所有有质量的物体之间的吸引力。月球上的重力场强度约为 1.6 N/kg，因此物体在那里重量较轻。助记："Weight 取决于 Where（地点），Mass 永远 Master（不变）。"
4. Density | 密度
me of a substance. Density = mass ÷ volume. Units are kg/m³ or g/cm³. A useful mnemonic is "Density is how tightly packed Dots (particles) are." A solid usually has high density because particles are close together.
密度是物质单位体积的质量。密度 = 质量 ÷ 体积。单位是 kg/m³ 或 g/cm³。助记："Density 就是点（粒子）排列的紧密程度。" 固体通常密度高因为粒子排列紧密。
ou cover the one you need, you see the calculation. For example, covering V gives V = M/D.
记忆公式三角形：M 在顶部，D 和 V 在底部两角：M = D × V。遮住所求量即可得算式，如遮住 V 得 V = M/D。
5. Energy Forms and Transfers | 能量形式与转移
Energy is the ability to do work. It exists in many forms: kinetic, potential (gravitational, elastic), thermal, chemical, electrical, light, sound and nuclear. The unit is the joule (J). Say: "Energy Joins all forms."
能量是做功的能力。存在多种形式：动能、势能（重力势能、弹性势能）、热能、化学能、电能、光能、声能、核能。单位是焦耳(J)。助记："Energy Joins all forms"（能量 Join 所有形式，J对应焦耳）。
Energy can be transferred between stores by forces, heating, waves or electric currents. A common mnemonic for energy stores is "Kids Gave The Cat Eight Little Sweets" – Kinetic, Gravitational, Thermal, Chemical, Elastic, Light, Sound (Electrical and Nuclear can be added).
能量可通过力、加热、波或电流在不同储存间转移。能量储存助记："Kids Gave The Cat Eight Little Sweets" – 动能、重力势能、热能、化学能、弹性势能、光能、声能（可加上电与核）。
6. Thermal Energy and Heat Transfer | 热能及热传递
Heat is the transfer of thermal energy from a hotter object to a cooler one. Temperature measures how hot or cold something is, in degrees Celsius (°C). Think: "Temperature is a thermometer number; heat is the energy flow."
热量是从较热物体向较冷物体传递的热能。温度衡量物体冷热程度，单位摄氏度(°C)。区分："温度是温度计读数；热量是能量的流动。"
Conduction is heat transfer in solids via particle vibrations. Metals are good conductors. Convection occurs in fluids (liquids and gases) by movement of particles due to density changes. Radiation is heat transfer by infrared waves, can travel through a vacuum. Remember: "Conduction needs contact, Convection circulates, Radiation radiates through space."
传导是热量在固体中通过粒子振动传递。金属是良导体。对流发生在流体中，由密度变化引起粒子运动传递热量。辐射是通过红外波传递热量，可在真空中传播。助记："Conduction 需接触，Convection 循环流，Radiation 穿真空。"
7. Waves and Sound | 波与声
A wave is a disturbance that transfers energy without transferring matter. Transverse waves (e.g., light) oscillate perpendicular to the direction of energy transfer; longitudinal waves (e.g., sound) oscillate parallel. Visualise: in a stadium wave, people move up and down (transverse), but energy moves sideways.
波是传播能量而不传播物质的扰动。横波（如光）振动方向与能量传递方向垂直；纵波（如声）振动方向平行。想象："人浪"中人们上下运动（横波），能量却水平传递。
Sound is produced by vibrating objects, travels as a longitudinal wave and needs a medium (solid, liquid or gas). Its speed is about 340 m/s in air. Remember: "Sound needs Substance; in Space, Silence."
声音由物体振动产生，以纵波形式传播，需要介质（固液气）。空气中声速约 340 m/s。助记："Sound 需要 Substance（物质）；太空太空，寂静无声。"
maximum displacement from rest. Pitch relates to frequency; loudness to amplitude. Think: "High Frequency = High Pitch."
频率是每秒波的个数，单位赫兹(Hz)。振幅是偏离平衡的最大位移。音调与频率有关；响度与振幅有关。助记："高频 High Frequency = 高音 High Pitch。"
8. Light and Shadows | 光与影子
Light travels in straight lines at about 300,000,000 m/s in a vacuum. A shadow is formed when an opaque object blocks light. Remember: "Light goes straight unless it bends (refraction) or bounces (reflection)."
光在真空中沿直线传播，速度约 3×10⁸ m/s。不透明物体挡住光线就形成影子。助记："光走直线，除非折射或反射。"
on. These angles are measured from the normal, an imaginary line perpendicular to the surface. Mnemonic: "Normal is the line of 90 degrees; angles are equal as twins."
反射是光从表面反弹。反射定律：入射角 = 反射角。这些角从法线（垂直于表面的假想线）量起。助记："法线是90度线；入射反射如孪生。"
Published by TutorHao | Year 8 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