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COMC(Canadian Open Mathematics Challenge)加拿大数学奥赛，又称加拿大数学公开赛，是由国际权威学术机构加拿大数学学会 (CMS) 举办。作为加拿大最具影响力的数学学术活动，每年参加人数高达上万，除此之外，COM...
Edexcel A Level Physics:复习笔记5.20 Thin Lenses in Combination
Thin Lenses in Combination When multiple lenses are used in series (one after the other) this is called a compound lens To find the total power of a compound lens, find the sum of the powers of the...
Edexcel A Level Physics:复习笔记5.19 Power of a Lens
Power of a Lens The power of a lens is a measure of its ability to refract light The more refraction a lens causes, the higher its power The power of a lens measures how strongly it focuses the lig...
Edexcel A Level Physics:复习笔记5.18 Using Ray Diagrams
Using Ray Diagrams Describing images formed by lenses Images are described using three concepts They are either: Real or virtual Bigger than, the same size as or smaller than the object Inverted or...
Edexcel A Level Physics:复习笔记5.17 Converging & Diverging Lenses
Converging & Diverging Lenses A lens is a piece of equipment that forms an image by refracting light There are two types of lens: Convex Concave Convex Lenses In a convex lens, parallel ...
Edexcel A Level Physics:复习笔记5.16 Measuring Refractive Index
Measuring Refractive Index Aim of the Experiment To investigate the refraction of light through a perspex block Equipment Ray Box - to provide a narrow beam of light to refract through the perspex ...
Edexcel A Level Physics:复习笔记5.15 Total Internal Reflection
Total Internal Reflection Total internal reflection (TIR) occurs when: The angle of incidence is greater than the critical angle and the incident refractive index n1 is greater than the refractive ...
Edexcel A Level Physics:复习笔记5.14 Critical Angle
Critical Angle As the angle of incidence is increased, the angle of refraction also increases until it gets to 90° When the angle of refraction is exactly 90° the light is refracted along the bound...
Edexcel A Level Physics:复习笔记5.13 Refraction & Refractive Index
Refraction & Refractive Index Refraction occurs when light passes a boundary between two different transparent media At the boundary, the rays of light undergo a change in direction and a chang...
Edexcel A Level Physics:复习笔记5.12 Equation for the Intensity of Radiation
Equation for the Intensity of Radiation Progressive waves transfer energy The amount of energy passing through a unit area per unit time is the intensity of the wave Therefore, the intensity is def...
Edexcel A Level Physics:复习笔记5.11 Core Practical 7: Investigating Stationary Waves
Core Practical 7: Investigating Stationary Waves Aims of the Experiment The overall aim of the experiment is to measure how the frequency of the first harmonic is affected by changing one of the fo...
Edexcel A Level Physics:复习笔记5.10 Wave Speed on a Stretched String
Wave Speed on a Stretched String The speed of a wave travelling along a string with two fixed ends is given by: Where: T = tension in the string (N) μ = mass per unit length of the string (kg m–1) ...
