📚 WJEC Year 9 Physics: Glossary & Fast Memory Guide | WJEC 九年级物理：词汇术语速记指南
Mastering the essential vocabulary in Year 9 Physics is your first step towards solving problems and explaining how the universe works. This bilingual guide collects the most important WJEC terms, clear definitions, and simple memory tricks to help you learn faster and remember longer.
掌握九年级物理的核心词汇是你解题和解释宇宙运行原理的第一步。这份双语指南汇集了WJEC最重要的术语、清晰的定义和简单的记忆技巧，帮你学得更快、记得更牢。
1. Motion and Vectors | 运动与矢量
Distance: The total length of the path an object travels, no matter which direction it moves. It is a scalar quantity and measured in metres (m).
距离：物体运动路径的总长度，与方向无关；是一个标量，单位为米（m）。
Displacement: The straight-line distance from the starting point to the finishing point in a specified direction. It is a vector quantity.
位移：从起点到终点的直线距离，并带有明确方向；是一个矢量。
Speed: How fast an object moves, calculated as distance travelled divided by time taken. Speed is a scalar, typically in m/s.
速率：物体运动的快慢，等于路程除以时间；标量，单位通常为 m/s。
Velocity: The speed of an object in a particular direction; rate of change of displacement. It is a vector, and its magnitude is speed.
速度：物体在某一方向上的运动快慢；位移的变化率，是矢量，其大小等于速率。
Acceleration eleration = change in velocity / time taken, a = Δv / Δt. It is a vector measured in m/s².
加速度：速度的变化率，公式为 a = Δv / Δt；矢量，单位为 m/s²。
Scalar: A physical quantity that has only magnitude (size), such as distance, speed, mass and energy.
标量：只有大小、没有方向的物理量，如距离、速率、质量和能量。
Vector: A quantity that has both magnitude and direction, for example displacement, velocity, acceleration and force.
矢量：既有大小又有方向的物理量，例如位移、速度、加速度和力。
2. Forces and Newton's Laws | 力与牛顿定律
Force: A push or pull that can change an object's shape, speed or direction. Force is a vector measured in newtons (N).
力：能改变物体形状、速率或方向的推或拉；矢量，单位为牛顿（N）。
Newton: The SI unit of force. One newton is the force needed to give a mass of 1 kilogram an acceleration of 1 m/s².
牛顿：力的国际单位；1 牛顿是使 1 千克物体产生 1 m/s² 加速度所需的力。
Weight n an : The gravitational force acting on an object. Weight = mass × gravitational field strength, W = m g. On Earth g ≈ 9.8 N/kg.
重量：作用在物体上的重力，W = m g；地球上 g ≈ 9.8 N/kg。
Mass: The amount of matter in an object, measured in kilograms (kg). Mass does not change with location.
质量：物体所含物质的多少，单位为千克（kg）；不随地点改变。
Gravitational field strength (g): The force per unit mass acting on an object in a gravitational field. Near Earth's surface, g ≈ 9.8 N/kg.
重力场强度 (g)：重力场中作用在单位质量上的力；地球表面约 9.8 N/kg。
Friction: A force that opposes motion between two surfaces in contact. It can be useful (walking) or unwanted (engine wear).
摩擦力：阻碍接触面之间相对运动的力；可以是有益的（行走）或有害的（发动机磨损）。
Air resistance (drag): A type of friction that acts on objects moving through the air; it increases with speed and surface area.
空气阻力：物体在空气中运动时受到的摩擦力，随速度和面积增大而增大。
Resultant force: The single overall force that has the same effect as all the forces acting on an object. When resultant force is zero, forces are balanced.
合力：与作用在物体上所有力效果相同的单一力；合力为零时，力平衡。
Tension: The pulling force transmitted through a string, cable or rope when it is pulled tight.
张力：通过拉紧的绳子、缆绳传递的拉力。
Normal reaction force: The support force exerted by a surface on an object resting on it; acts perpendicular to the surface.
法向反作用力：表面作用在物体上的支持力，方向垂直于表面。
3. Energy and Work | 能量与功
Energy: The ability to do work. It is measured in joules (J) and exists in many forms such as kinetic, potential, thermal and light.
能量：做功的能力，单位为焦耳（J）；存在动能、势能、热能和光能等多种形式。
Work done hen a force moves an object. Work = force × distance moved in direction of force, W = F d.
做功：力使物体移动时做功；功 = 力 × 沿力方向移动的距离，W = F d。
Kinetic energy (Eₖ) e energy an object has because of its motion. Eₖ = ½ m v², where m is mass and v is speed.
动能 (Eₖ)：物体因运动而具有的能量，Eₖ = ½ m v²。
Gravitational potential energy (Eₚ): Energy stored in an object due to its height above the ground. Eₚ = m g h.
重力势能 (Eₚ)：物体因离地高度而储存的能量，Eₚ = m g h。
Elastic potential energy: Energy stored in a stretched or compressed spring or elastic band. The more it is stretched, the greater the stored energy.
弹性势能：拉伸或压缩的弹簧或橡皮筋中储存的能量；形变越大，能量越多。
Conservation of energy: Energy can be transferred or transformed but cannot be created or destroyed. The total energy of an isolated system stays constant.
能量守恒：能量可以转移或转化，但不能凭空产生或消失；孤立系统的总能量保持不变。
Power ork is done or energy is transferred. Power = work done / time, P = W / t. Unit: watt (W).
功率：做功或能量转移的速率，P = W / t；单位为瓦特（W）。
Efficiency : The ratio of useful output energy to total input energy, often expressed as a percentage. Efficiency = (useful output / total input) × 100%.
效率：有用输出能量与总输入能量的比值，通常用百分比表示；效率 = （有用输出/总输入）×100%。
4. Heat and Temperature | 热与温度
Temperature: A measure of how hot or cold an object is, linked to the average kinetic energy of its particles. Measured in degrees Celsius (°C) or kelvin (K).
温度：衡量物体冷热程度的量，与粒子平均动能相关；单位为摄氏度（°C）或开尔文（K）。
Thermal energy: The total kinetic and potential energy of all the particles in a substance. It depends on mass, temperature and material.
热能：物质内所有粒子的总动能和势能；取决于质量、温度和材料。
Heat: The transfer of thermal energy from a hotter object to a cooler one. Heat flows until thermal equilibrium is reached.
热量：热能从高温物体向低温物体的转移；热量流动直到热平衡。
Conduction: The transfer of heat through a solid by particle vibration without any overall movement of the material. Metals are good conductors.
传导：热量通过固体中粒子振动传递、材料本身不移动；金属是良导体。
Convection: The transfer of heat in fluids (liquids and gases) by the movement of the fluid itself. Hot fluid rises, cooler fluid sinks.
对流：在流体（液体和气体）中通过流体本身流动传递热量；热流体上升，冷流体下沉。
Radiation: The transfer of energy by electromagnetic waves, mainly infrared. No particles are needed; it can travel through a vacuum.
辐射：通过电磁波（主要是红外线）传递能量；无需介质，可在真空中传播。
Conductor: A material that allows heat to flow through it easily, such as copper and aluminium.
导热体：允许热量轻易通过的材料，如铜和铝。
Insulator: A material that reduces the rate of heat transfer, for example wood, plastic and wool.
绝热体：降低热量传递速率的材料，如木材、塑料和羊毛。
5. Waves: Basics | 波的基础
Wave: A disturbance that transfers energy from one place to another without transferring matter. Waves can be mechanical or electromagnetic.
波：传递能量而不传递物质的扰动；可分为机械波和电磁波。
Transverse wave: A wave in which the oscillations are perpendicular to the direction of energy transfer. Examples include light waves and water waves.
横波：振动方向与能量传递方向垂直的波，如光波和水波。
Longitudinal wave: A wave where the oscillations are parallel to the direction of energy transfer. Sound waves in air are longitudinal.
纵波：振动方向与能量传递方向平行的波；空气中的声波是纵波。
Amplitude: The maximum displacement of a point on the wave from its rest position. Larger amplitude means more energy.
振幅：波上某点离开平衡位置的最大位移；振幅越大，能量越大。
Wavelength (λ): The distance between two corresponding points on consecutive waves, such as crest to crest or trough to trough.
波长 (λ)：相邻两个波上同位点之间的距离，如波峰到波峰或波谷到波谷。
Frequency (f) mplete waves passing a point per second. Measured in hertz (Hz). 1 Hz = 1 wave per second.
频率 (f)：每秒通过某点的完整波的数量，单位为赫兹（Hz）；1 Hz = 1 次/秒。
Period (T): The time taken for one complete wave cycle. Period = 1 / frequency, T = 1 / f.
周期 (T)：完成一次完整波动所需的时间；T = 1 / f。
Wave speed : The speed at which the wave disturbance travels. Wave speed = frequency × wavelength, v = f λ.
波速：波扰动传播的速度；波速 = 频率 × 波长，v = f λ。
6. Sound and Light | 声音与光
Sound wave: A longitudinal mechanical wave caused by vibrating objects. Sound requires a medium (solid, liquid or gas) and cannot travel through a vacuum.
声波：由物体振动产生的纵机械波；声音需要介质（固、液、气），不能在真空中传播。
Ultrasound: Sound with frequencies higher than 20 000 Hz, above the range of human hearing. Used in medical scanning and sonar.
超声波：频率超过 20 000 Hz 的声音，超出人耳听觉范围；用于医学扫描和声呐。
Echo: A reflected sound wave that can be heard distinctly after bouncing off a surface. Used by bats and in echo-location.
回声：经表面反射后可清晰听到的声波；蝙蝠和回声定位利用回声。
Reflection e when it hits a surface. The law of reflection: angle of incidence = angle of reflection.
反射：波碰到表面时反弹回来的现象；反射定律：入射角等于反射角。
Refraction: The bending of a wave as it passes from one medium to another due to a change in speed. Light refracts when entering glass or water.
折射：波因速度变化在穿过不同介质时发生的偏折现象；光进入玻璃或水时会发生折射。
Dispersion: The splitting of white light into its spectrum of colours (red, orange, yellow, green, blue, indigo, violet) because different colours refract by different amounts.
色散：白光因其不同颜色折射程度不同而分解成光谱（红、橙、黄、绿、蓝、靛、紫）的现象。
Electromagnetic spectrum: The family of transverse waves that all travel at the speed of light in a vacuum. In order of increasing frequency: radio, microwave,
Published by TutorHao | Year 9 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