📚 Year 10 Cambridge Physics: Quick Reference Handbook of Formulas and Theorems | 剑桥10年级物理：公式定理速查手册
This handy reference handbook compiles all essential formulas and theorems for Year 10 Cambridge Physics. Whether you're revising for mocks or preparing for your final IGCSE, these equations are your best friends. Keep them close!
这本速查手册汇集了剑桥10年级物理学的所有重要公式和定理。无论你是在为模拟考试复习还是准备最终的IGCSE考试，这些公式都是你的最佳伙伴。请妥善保存！
1. Kinematics Formulas | 运动学公式
Kinematics describes the motion of objects without considering the forces that cause the motion. In Year 10, we focus on uniformly accelerated motion along a straight line. Three equations connect displacement (s), initial velocity (u), final velocity (v), acceleration (a) and time (t).
运动学描述物体的运动而不考虑引起运动的力。在10年级，我们专注于匀加速直线运动。三个方程联系了位移 (s)、初速度 (u)、末速度 (v)、加速度 (a) 和时间 (t)。
v = u + a t
Equation 1: Final velocity equals initial velocity plus acceleration multiplied by time. This version does not involve displacement.
公式1：末速度等于初速度加上加速度乘以时间。此形式不含位移。
s = u t + ½ a t²
Equation 2: Displacement is initial velocity multiplied by time plus half the acceleration multiplied by the square of time. Use this when final velocity is not given.
公式2：位移等于初速度乘以时间加上二分之一加速度乘以时间的平方。当末速度未知时使用此式。
v² = u² + 2 a s
Equation 3: The square of final velocity equals the square of initial velocity plus twice the acceleration multiplied by displacement. It is independent of time.
公式3：末速度的平方等于初速度的平方加上两倍加速度乘以位移。此式与时间无关。
2. Forces and Newton's Laws | 力与牛顿定律
Newton's laws form the foundation of classical mechanics. The resultant force acting on an object causes it to accelerate, and this relationship is expressed by the second law.
牛顿定律是经典力学的基础。作用在物体上的合力使其加速，这一关系由牛顿第二定律表达。
F = m a
Resultant force (N) equals mass (kg) multiplied by acceleration (m/s²). Always use the net force when applying this equation.
合力 (牛) 等于质量 (千克) 乘以加速度 (米/秒²)。应用此公式时务必使用净力。
W = m g
Weight (W) is the gravitational force on an object. On Earth, the gravitational field strength g is approximately 9.8 N/kg. Weight is a force and is measured in newtons.
重量 (W) 是作用在物体上的重力。在地球上，重力场强度 g 约为 9.8 牛/千克。重量是一种力，单位为牛顿。
Newton's third law: For every action force there is an equal and opposite reaction force. These forces act on different bodies and never cancel out on the same object.
牛顿第三定律：对于每一个作用力，都有一个大小相等、方向相反的反作用力。这两个力作用在不同的物体上，永远不会在同一个物体上相互抵消。
3. Momentum | 动量
Momentum is a measure of how difficult it is to stop a moving object. It depends on both mass and velocity and is a vector quantity. The principle of conservation of momentum is key to solving collision problems.
动量是衡量一个运动物体难易停止程度的量。它取决于质量和速度，是矢量。动量守恒原理是解决碰撞问题的关键。
p = m v
Linear momentum p (kg m/s) is the product of mass m and velocity v. The direction of momentum is the same as the velocity.
线动量 p (千克·米/秒) 是质量 m 与速度 v 的乘积。动量的方向与速度相同。
m₁ u₁ + m₂ u₂ = m₁ v₁ + m₂ v₂
In a closed system, total momentum before a collision equals total momentum after the collision. Subscripts 1 and 2 refer to two objects; u denotes initial velocity and v denotes final velocity.
在封闭系统中，碰撞前的总动量等于碰撞后的总动量。下标 1 和 2 分别代表两个物体；u 表示初速度，v 表示末速度。
4. Energy, Work and Power | 能量、功与功率
Energy can be stored or transferred. Kinetic and gravitational potential energy are two major mechanical stores. Work done equals energy transferred, and power is the rate of doing work.
能量可以储存或转移。动能和重力势能是两种主要的机械能储存形式。做功等于能量转移，功率是做功的速率。
KE = ½ m v²
Kinetic energy (J) is one‑half the product of mass and the square of its speed. A faster object has a much larger kinetic energy due to the square relation.
动能 (焦) 等于质量与速度平方乘积的一半。由于平方关系，速度越快的物体动能大得多。
GPE = m g h
Gravitational potential energy gained by lifting an object of mass m through a vertical height h in a gravitational field of strength g.
重力势能是将质量为 m 的物体在重力场强度为 g 的场中竖直提升高度 h 所获得的能量。
W = F d
Work done (J) by a constant force F is the force multiplied by the displacement d in the direction of the force. If the force is perpendicular to motion, no work is done.
力所做的功 (焦) 等于恒力 F 乘以在力方向上的位移 d。如果力与运动方向垂直，则不做功。
P = W / t = F v
Power P (watt) is the work done per unit time. For an object moving at constant speed v, power is also the product of the force and velocity.
功率 P (瓦) 是单位时间内做的功。对于以恒定速度 v 运动的物体，功率也可以表示为力与速度的乘积。
5. Pressure | 压强
Pressure describes how concentrated a force is. In fluids, pressure depends on density, depth and gravitational field strength. Solid pressure and fluid pressure are both essential.
压强描述力有多么集中。在流体中，压强取决于密度、深度和重力场强度。固体压强和流体压强都很重要。
P = F / A
General definition: pressure P (Pa or N/m²) is the force F acting perpendicularly per unit area A. A large area reduces pressure for a given force.
通用定义：压强 P (帕或牛/米²) 是垂直作用在单位面积 A 上的力 F。给定力下，大面积可减小压强。
p = ρ g h
of liquid column. This formula works for a static liquid and ignores atmospheric pressure.
液体在深度 h 处的压强：p = 密度 (ρ) × 重力场强度 (g) × 液柱高度。该公式适用于静止液体，不计大气压。
6. Thermal Physics | 热物理
When heat is added to a substance, its temperature may rise or it may change state. The specific heat capacity governs the temperature change, while the specific latent heat governs the phase change without temperature change.
当热量传递给物质时，其温度可能升高或发生物态变化。比热容决定温度变化，而比潜热决定无温度变化的相变。
Q = m c Δθ
Heat energy Q (J) needed to raise the temperature of mass m by Δθ: c is the specific heat capacity (J/(kg °C)). The same formula applies for cooling, with a negative Δθ.
将质量 m 的温度升高 Δθ 所需的热能 Q (焦)：c 是比热容 (焦/(千克·摄氏度))。降温时同样适用，Δθ 为负。
Q = m L
Heat energy Q required to change the state of mass m at constant temperature: L is the specific latent heat (J/kg). Use Lf for fusion (melting/freezing) and Lv for vaporisation (boiling/condensing).
在恒定温度下改变质量 m 的物态所需的热能 Q：L 是比潜热 (焦/千克)。熔化/凝固用 Lf，汽化/液化用 Lv。
7. Waves | 波动
Waves transfer energy without transferring matter. The wave speed, frequency and wavelength are linked by a simple equation. Frequency and period are reciprocals.
波传递能量而不传递物质。波速、频率和波长由一个简单的公式联系。频率与周期互为倒数。
v = f λ
Wave speed v (m/s) equals frequency f (Hz) multiplied by wavelength λ (m). This applies to all wave types – water waves, sound, light and radio waves.
波速 v (米/秒) 等于频率 f (赫兹) 乘以波长 λ (米)。这适用于所有波类型——水波、声波、光波和无线电波。
f = 1 / T
Frequency is the number of complete oscillations per second; period T is the time for one complete oscillation. They are inversely related.
频率是每秒完整振动的次数；周期 T 是一次完整振动所需的时间。两者互为倒数。
8. Optics | 光学
Optics deals with the behaviour of light. Snell's law describes refraction at a boundary, while the thin lens equation and magnification relate object distance, image distance and focal length for lenses. Ray diagrams should be used alongside these formulas.
光学研究光的行为。斯涅尔定律描述边界处的折射，而薄透镜公式和放大率关联了透镜的物距、像距和焦距。这些公式应配合光路图使用。
n = sin i / sin r
Refractive index n of a medium: i is the angle of incidence in vacuum (or air) and r is the angle of refraction in the medium. n is always greater than 1 for a denser medium.
介质的折射率 n：i 是真空 (或空气) 中的入射角，r 是介质中的折射角。对于光密介质，n 总大于1。
1 / f = 1 / u + 1 / v
Thin lens equation: u is the object distance from the lens, v is the image distance, f is the focal length. Use sign conventions (real‑is‑positive) when applying the formula.
薄透镜公式：u 是物距，v 是像距，f 是焦距。使用公式时遵循符号法则 (通常实为正)。
m = v / u
Linear magnification m is the ratio of image height to object height, and also equals the ratio of image distance to object distance for a thin lens.
线性放大率 m 是像高与物高之比，对于薄透镜也等于像距与物距之比。
9. Electricity | 电学
Electric circuits can be analysed using Ohm's law and rules for combining resistances. Power consumption in resistors depends on current, voltage and resistance.
电路可以用欧姆定律和电阻组合规则进行分析。电阻器消耗的功率取决于电流、电压和电阻。
V = I R
Ohm's law: the voltage V across a resistor is proportional to the current I through it, provided temperature is constant. R is the resistance in ohms (Ω).
欧姆定律：在温度不变时，电阻两端的电压 V 与流过它的电流 I 成正比。R 是电阻，单位为欧姆 (Ω)。
P = I V = I² R = V² / R
Electrical power P (W) can be expressed in three equivalent ways. Use the form that matches the given quantities. The I²R formula highlights the power loss due to heating.
电功率 P (瓦) 有三种等价表达。选择与已知量匹配的形式。I²R 公式突出显示了因发热造成的功率损耗。
Rtotal = R₁ + R₂ + ... (series)
Resistors in series: the total resistance is the sum of the individual resistances. Current is the same through all components.
串联电阻：总电阻为各电阻之和。通过所有元件的电流相同。
1 / Rtotal = 1 / R₁ + 1 / R₂ + ... (parallel)
Resistors in parallel: the reciprocal of the total resistance is the sum of the reciprocals of individual resistances. The voltage across each branch is the same.
并联电阻：总电阻的倒数是各电阻倒数之和。每个支路两端的电压相同。
The resistance of a wire depends on its length, cross‑sectional area and the material: R = ρ L / A, where ρ is resistivity.
导线的电阻取决于其长度、横截面积和材料：R = ρ L / A，其中 ρ 是电阻率。
10. Electromagnetism | 电磁学
Electromagnetism covers how electric currents produce magnetic fields and how changing magnetic fields induce voltages. The transformer equation is vital for understanding step‑up and step‑down transformers.
电磁学研究电流如何产生磁场以及变化的磁场如何感应出电压。变压器方程对于理解升压和降压变压器至关重要。
Vₚ / Vₛ = Nₚ / Nₛ
o that in the secondary coil Nₛ. An efficient transformer assumes power input ≈ power output.
理想变压器方程：初级电压 Vₚ 与次级电压 Vₛ
Published by TutorHao | Year 10 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