📚 Year 11 Cambridge Physics: Core Concepts Overview | Year 11 Cambridge 物理核心知识点梳理
This article provides a structured recap of the fundamental topics covered in Year 11 Cambridge Physics, aligned with the Cambridge IGCSE syllabus. It is designed to help you consolidate key definitions, formulas, and applications efficiently.
本文系统梳理了 Year 11 Cambridge 物理的核心知识点，严格对应 Cambridge IGCSE 考纲，帮助你高效巩固关键定义、公式及其应用。
1. Measurements and Units | 测量与单位
Physical quantities are expressed using SI base units: metre (m), kilogram (kg), second (s), ampere (A), kelvin (K), and mole (mol). Derived units such as newton (N) and pascal (Pa) combine these bases.
物理量使用国际单位制基本单位表示：米(m)、千克(kg)、秒(s)、安培(A)、开尔文(K)和摩尔(mol)。导出单位如牛顿(N)和帕斯卡(Pa)由基本单位组合而成。
Always record measurements with appropriate precision and significant figures. Use instruments like micrometers and vernier calipers for small lengths, and ensure parallax error is avoided.
记录测量值时要注意精确度和有效数字。使用千分尺和游标卡尺测量微小长度，并确保避免视差误差。
2. Kinematics | 运动学
direction. Acceleration is the rate of change of velocity, calculated by a = (v - u) / t.
速率是距离变化的快慢，而速度是带方向的速率。加速度是速度变化的快慢，由公式 a = (v - u)/t 计算。
For uniformly accelerated motion, the equations of motion apply:
v = u + at
s = ut + ½at²
v² = u² + 2as
其中 u 为初速度，v 为末速度，a 为加速度，t 为时间，s 为位移。
Distance–time graphs: gradient gives speed. Velocity–time graphs: gradient gives acceleration, area under graph gives displacement.
距离-时间图：斜率表示速率。速度-时间图：斜率表示加速度，图线下面积表示位移。
3. Dynamics | 动力学
Newton's first law states that an object remains at rest or in uniform motion unless acted upon by a resultant force. Inertia is the tendency to resist change in motion.
牛顿第一定律：物体在不受合力作用时将保持静止或匀速直线运动状态。惯性是抗拒运动状态变化的倾向。
Newton' of an object is directly proportional to the resultant force and inversely proportional to its mass.
牛顿第二定律：F = ma。物体的加速度与所受合力成正比，与其质量成反比。
Newton's third law: For every action, there is an equal and opposite reaction. These forces act on different bodies.
牛顿第三定律：作用力与反作用力大小相等、方向相反，且作用在不同的物体上。
tational force on a mass. Friction opposes motion and can be both helpful and a hindrance.
重量 W = mg 是质量所受的重力。摩擦力阻碍运动，既可能是有益的也可能是有害的。
4. Energy, Work and Power | 能量、功与功率
Energy can be stored in various forms: kinetic (½mv²), gravitational potential (mgh), elastic potential, chemical, nuclear, thermal, and more. The principle of conservation of energy states that energy cannot be created or destroyed, only transferred or converted.
能量可以多种形式储存：动能(½mv²)、重力势能(mgh)、弹性势能、化学能、核能、热能等。能量守恒定律指出能量既不能凭空产生也不能消失，只能转移或转化。
when a force moves an object: W = Fd. Power is the rate of doing work: P = W/t or P = Fv.
力使物体移动时做功：W = Fd。功率是做功的快慢：P = W/t 或 P = Fv。
Efficiency = (useful energy output / total energy input) × 100% nergy is always dissipated as thermal energy, increasing the disorder of the surroundings.
效率 = (有用输出能 / 总输入能) × 100%。在能量转移中，总有一部分能量以热能形式耗散，增加周围环境的无序度。
5. Thermal Physics | 热物理学
Temperature is a measure of the average kinetic energy of particles. Heat is thermal energy transferred from a hotter to a cooler region.
温度是粒子平均动能的量度。热量是从高温区域传递到低温区域的热能。
t, L, is the energy needed to change the state of 1 kg without temperature change: Q = mL.
比热容 c 是使 1 kg 物质温度升高 1°C 所需的能量：Q = mcΔθ。比潜热 L 是使 1 kg 物质在温度不变时发生状态变化所需的能量：Q = mL。
Thermal expansion: most substances expand when heated due to increased particle vibration. The anomalous expansion of water (maximum density at 4 °C) is important for aquatic life.
热膨胀：多数物质受热时因粒子振动加剧而膨胀。水的反常膨胀（4°C 时密度最大）对水生生物至关重要。
6. Waves | 波
Waves transfer energy without net movement of matter. Transverse waves (e.g., light, water ripples) have oscillations perpendicular to direction of travel; longitudinal waves (e.g., sound) have oscillations parallel to travel.
波传递能量而不伴随物质的净移动。横波（如光、水波）的振动方向垂直于传播方向；纵波（如声波）的振动方向平行于传播方向。
ngth. The period T = 1/f. Reflection, refraction, and diffraction are key wave behaviours.
波速 v = fλ，f 为频率，λ 为波长。周期 T = 1/f。反射、折射和衍射是波的主要行为。
ng a change in direction unless incident normally. The refractive index n = sin i / sin r.
折射发生时，波在穿越界面时速度改变，若入射不垂直于界面则方向改变。折射率 n = sin i / sin r。
pectrum: radio waves, microwaves, infrared, visible light, ultraviolet, X-rays, gamma rays – all travel at 3.00 × 10⁸ m/s in a vacuum.
电磁波谱：无线电波、微波、红外线、可见光、紫外线、X 射线、伽马射线——在真空中均以 3.00×10⁸ m/s 传播。
7. Electricity | 电学
the energy per unit charge: V = W/Q. Resistance (R) is the opposition to current: R = V/I.
电流 I 是电荷流动的速率：I = Q/t。电压 V 是单位电荷的能量：V = W/Q。电阻 R 是对电流的阻碍：R = V/I。
Ohm’s law states that, at constant temperature, the current through a metallic conductor is directly proportional to the potential difference across it.
欧姆定律指出，在温度不变时，通过金属导体的电流与其两端的电压成正比。
ries circuits: current is the same through all components, total resistance Rₜ = R₁ + R₂ + … ifference splits. Parallel circuits: current splits, total resistance 1/Rₜ = 1/R₁ + 1/R₂ + …, pd is the same across each branch.
串联电路：各处电流相等，总电阻 Rₜ = R₁ + R₂ + …，电压按比例分配。并联电路：电流分流，总电阻 1/Rₜ = 1/R₁ + 1/R₂ + …，各支路两端电压相等。
Electrical power P = IV = I²R = V²/R. Energy transferred E = Pt = IVt.
电功率 P = IV = I²R = V²/R。转换的电能 E = Pt = IVt。
8. Magnetism and Electromagnetism | 磁学与电磁学
Like poles repel, unlike poles attract. Magnetic field lines run from north to south. A current-carrying wire produces a circular magnetic field; the right-hand grip rule determines direction.
同名磁极相斥，异名相吸。磁感线从北极指向南极。通电导线产生环形磁场，用右手螺旋定则判定方向。
Electromagnets are temporary magnets that can be switched on and off, used in relays, bells, and circuit breakers.
电磁体是可开关的临时磁体，应用于继电器、电铃和断路器。
When a conductor cuts magnetic field lines, an e.m.f. is induced (electromagnetic induction). The induced current opposes the change producing it (Lenz’s law). A simple a.c. generator and d.c. motor use these principles.
当导线切割磁感线时，会产生感应电动势（电磁感应）。感应电流的方向总是阻碍引起它的变化（楞次定律）。简单的交流发电机和直流电动机利用这些原理。
d for an ideal transformer VₚIₚ = VₛIₛ. Step-up increases voltage; step-down decreases it.
变压器改变电压：Vₚ/Vₛ = Nₚ/Nₛ，理想变压器满足 VₚIₚ = VₛIₛ。升压变压器升高电压，降压变压器降低电压。
9. Atomic Physics | 原子物理学
electrons. Proton number (Z) defines the element; nucleon number (A) = protons + neutrons.
原子由原子核（质子和中子）和核外电子组成。质子数(Z)决定元素种类；核子数(A)=质子数+中子数。
Radioactive decay is random and spontaneous. Alpha particles (α) are helium nuclei, beta particles (β⁻) are high-speed electrons, gamma rays (γ) are electromagnetic waves.
放射性衰变是随机且自发的。α 粒子是氦核，β⁻ 粒子是高速电子，γ 射线是电磁波。
Half-life is the time for half the radioactive nuclei in a sample to decay. Background radiation comes from natural and artificial sources. Ionising radiation can be detected with a Geiger–Müller tube.
半衰期是样本中半数放射性原子核衰变所需的时间。本底辐射来自天然和人造源。电离辐射可用盖革-米勒管探测。
Uses include tracers, radiotherapy, and carbon dating. Safety precautions involve shielding, minimising exposure time, and increasing distance.
应用包括示踪剂、放射治疗和碳定年法。安全防护包括屏蔽、缩短暴露时间和加大距离。
10. Forces, Moments and Pressure | 力、力矩与压强
Adding forces: vectors can be combined head-to-tail. The resultant force is the single force producing the same effect. Resolving forces splits a single force into perpendicular components.
力的合成：矢量可以通过首尾相接法相加。合力是能产生相同效果的单个力。力的分解将一个力分解为相互垂直的分量。
ance from pivot. For equilibrium, sum of clockwise moments = sum of anticlockwise moments.
力矩 = 力 × 到支点的垂直距离。平衡时，顺时针力矩之和等于逆时针力矩之和。
essure increases with depth: p = ρgh, and is transmitted equally in all directions (Pascal's principle).
压强 P = F/A。流体中压强随深度增加：p = ρgh，且向各个方向等大传递（帕斯卡原理）。
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