📚 IGCSE CCEA Science: Formula Compilation Handbook | IGCSE CCEA 科学：公式汇总手册
This comprehensive handbook brings together all the essential formulas needed for IGCSE CCEA Science, covering Physics, Chemistry and Biology. Each formula is presented with clear explanations, correct units and practical rearrangements to help you revise efficiently and apply your knowledge with confidence in the exam.
本手册汇总了 IGCSE CCEA 科学考试所需的所有重要公式，涵盖物理、化学和生物。每个公式都配以清晰的解释、正确的单位以及实用的变形，帮助你高效复习并在考试中自信运用。
1. Speed, Distance and Time | 速度、距离和时间
Average speed is obtained by dividing the total distance travelled by the time taken. The formula is: average speed = total distance ÷ time, or in symbols v = d / t. Speed is measured in metres per second (m/s) when distance is in metres and time in seconds.
平均速度等于总行驶距离除以所用时间。公式为：平均速度 = 总距离 ÷ 时间，或用符号表示为 v = d / t。当距离以米、时间以秒为单位时，速度的单位是米每秒 (m/s)。
To find distance from speed and time, rearrange: distance = speed × time.
根据速度和时间求距离：距离 = 速度 × 时间。
To find time from distance and speed: time = distance ÷ speed.
根据距离和速度求时间：时间 = 距离 ÷ 速度。
2. Acceleration | 加速度
Acceleration is the rate of change of velocity. It is calculated as: acceleration = change in velocity ÷ time taken, or a = (v − u) / t, where v is final velocity, u is initial velocity and t is time. The unit is metres per second squared (m/s²).
加速度是速度变化的速率。计算公式为：加速度 = 速度变化量 ÷ 所用时间，或 a = (v − u) / t，其中 v 为末速度，u 为初速度，t 为时间。单位为米每二次方秒 (m/s²)。
From this, the final velocity can be found: v = u + a × t. If the object starts from rest, u = 0, so v = a × t.
由此可求末速度：v = u + a × t。若物体从静止开始，则 u = 0，即 v = a × t。
The average velocity during uniform acceleration can be taken as: average velocity = (u + v) / 2.
匀加速过程中的平均速度可使用：平均速度 = (u + v) / 2。
3. Force, Mass and Acceleration | 力、质量和加速度
Newton’s second law relates resultant force, mass and acceleration: resultant force = mass × acceleration, or F = m × a. Force is measured in newtons (N) when mass is in kilograms (kg) and acceleration in m/s².
牛顿第二定律将合力、质量与加速度联系起来：合力 = 质量 × 加速度，即 F = m × a。质量以千克 (kg)、加速度以 m/s² 为单位时，力的单位为牛顿 (N)。
To calculate mass: m = F ÷ a. To find acceleration: a = F ÷ m.
求质量：m = F ÷ a。求加速度：a = F ÷ m。
4. Weight, Mass and Gravity | 重量、质量和重力
Weight is the force due to gravity acting on a mass. It is given by: weight = mass × gravitational field strength, W = m × g. On Earth, g ≈ 10 N/kg (or 9.8 N/kg). Weight is measured in newtons (N).
重量是重力作用在质量上的力。公式为：重量 = 质量 × 重力场强度，W = m × g。在地球上，g ≈ 10 N/kg（或 9.8 N/kg）。重量以牛顿 (N) 为单位。
Mass can be found by: m = W ÷ g.
质量可表示为：m = W ÷ g。
5. Moment of a Force | 力矩
The moment (turning effect) of a force about a pivot is: moment = force × perpendicular distance from pivot, M = F × d. The unit is newton metre (Nm). For equilibrium, the sum of clockwise moments equals the sum of anticlockwise moments.
力对支点的力矩（转动效应）为：力矩 = 力 × 力的作用线到支点的垂直距离，M = F × d。单位是牛顿米 (Nm)。平衡时，顺时针力矩之和等于逆时针力矩之和。
6. Density | 密度
Density describes how much mass is packed into a given volume. density = mass ÷ volume, or ρ = m / V. The SI unit is kilograms per cubic metre (kg/m³), though g/cm³ is also common. For a regular solid, volume = width × height × depth.
密度描述单位体积内所含的质量。密度 = 质量 ÷ 体积，即 ρ = m / V。国际单位为千克每立方米 (kg/m³)，但也常用 g/cm³。对于规则固体，体积 = 宽 × 高 × 深。
7. Pressure | 压强
Pressure is the force acting per unit area: pressure = force ÷ area, p = F / A. The unit is pascal (Pa) or N/m². In liquids, pressure due to a column of liquid is p = h × ρ × g, where h is depth.
压强是单位面积上所受的力：压强 = 力 ÷ 面积，p = F / A。单位是帕斯卡 (Pa) 或 N/m²。在液体中，由液柱产生的压强为 p = h × ρ × g，其中 h 为深度。
8. Energy, Work and Power | 能量、功和功率
Work done is force times distance moved in the direction of the force: work done = force × distance, W = F × d. It is measured in joules (J). Kinetic energy is KE = ½ × m × v². Gravitational potential energy is GPE = m × g × h.
功等于力乘以沿力方向移动的距离：做功 = 力 × 距离，W = F × d。单位是焦耳 (J)。动能为 动能 = ½ × m × v²。重力势能为 重力势能 = m × g × h。
Power is the rate of doing work: power = work done ÷ time, P = W / t. The unit is watt (W). Useful power output over total power input gives efficiency: efficiency = (useful output / total input) × 100%.
功率是做功的速率：功率 = 做功 ÷ 时间，P = W / t。单位是瓦特 (W)。有用输出功率与总输入功率的比值即为效率：效率 = (有用输出 / 总输入) × 100%。
9. Waves: Speed, Frequency and Wavelength | 波：波速、频率和波长
The wave equation links wave speed, frequency and wavelength: wave speed = frequency × wavelength, v = f × λ. Speed is in m/s, frequency in hertz (Hz) and wavelength in metres (m). A shorter wavelength at a constant speed gives a higher frequency.
波动方程将波速、频率和波长联系起来：波速 = 频率 × 波长，v = f × λ。波速单位为 m/s，频率为赫兹 (Hz)，波长为米 (m)。在波速一定时，波长越短，频率越高。
Frequency can be written as f = 1 / T, where T is the period in seconds.
频率也可表示为 f = 1 / T，其中 T 为周期，单位秒。
10. Electrical Calculations | 电学计算
Ohm’s law states: voltage = current × resistance, V = I × R. Voltage is in volts (V), current in amperes (A) and resistance in ohms (Ω).
欧姆定律指出：电压 = 电流 × 电阻，V = I × R。电压单位为伏特 (V)，电流为安培 (A)，电阻为欧姆 (Ω)。
Electrical power can be found using: P = I × V. Substituting V = I × R gives P = I² × R; substituting I = V / R gives P = V² / R. Power is measured in watts (W).
电功率可表示为：P = I × V。代入 V = I × R 得 P = I² × R；代入 I = V / R 得 P = V² / R。功率单位为瓦特 (W)。
Energy transferred is: energy = power × time, E = P × t, or energy = current × voltage × time, E = I × V × t. Energy is measured in joules (J) or kilowatt-hours (kWh).
能量转移量为：能量 = 功率 × 时间，E = P × t，或 能量 = 电流 × 电压 × 时间，E = I × V × t。能量单位是焦耳 (J) 或千瓦时 (kWh)。
11. Chemical Calculations: Moles, Concentration and Gas Volumes | 化学计算：摩尔、浓度与气体体积
The amount of substance in moles is given by: moles = mass (g) ÷ molar mass (g/mol), often written as n = m / M. The molar mass is the relative atomic or formula mass in grams.
物质的量（摩尔）的计算公式为：摩尔 = 质量 (g) ÷ 摩尔质量 (g/mol)，常写作 n = m / M。摩尔质量是以克为单位的相对原子质量或式量。
Concentration of a solution: concentration (mol/dm³) = moles ÷ volume (dm³), c = n / V. To convert cm³ to dm³, divide by 1000.
溶液的浓度：浓度 (mol/dm³) = 摩尔 ÷ 体积 (dm³)，c = n / V。将 cm³ 转换为 dm³ 需除以 1000。
At room temperature and pressure (RTP), one mole of any gas occupies 24 dm³: volume of gas (dm³) = moles × 24.
在室温和常压 (RTP) 下，任何气体 1 摩尔的体积为 24 dm³：气体体积 (dm³) = 摩尔 × 24。
12. Biology: Magnification and Rate of Reaction | 生物：放大率与反应速率
Magnification describes how many times larger an image is compared to the real object: magnification = image size ÷ actual size. Both dimensions must be in the same unit. This formula is vital for microscope drawings.
放大率表示图像与实物相比被放大了多少倍：放大率 = 图像尺寸 ÷ 实际尺寸。两者的尺寸单位必须相同。该公式是显微镜绘图中必不可少的。
The rate of an enzyme-controlled reaction can be calculated from the time taken for a set change: rate = 1 ÷ time (for the change to occur). The unit could be s⁻¹.
酶促反应的速率可通过发生设定变化所需的时间来计算：速率 = 1 ÷ 时间（变化所需时间）。单位可为 s⁻¹。
Percentage change is widely useful in data interpretation: percentage change = (final value − initial value) ÷ initial value × 100%.
百分比变化在数据分析中广泛使用：百分比变化 = (终值 − 初值) ÷ 初值 × 100%。
Published by TutorHao | Science Revision Series | aleveler.com
更多咨询请联系16621398022（同微信）
屏轩国际教育cambridge primary/secondary checkpoint, cat4, ukiset,ukcat,igcse,alevel,PAT,STEP,MAT, ibdp,ap,ssat,sat,sat2课程辅导，国外大学本科硕士研究生博士课程论文辅导