University Physics Midterm Exam Overview. 16. THE NATURE OF LIGHT Speed of light c = 3x10 8 m/s (in the vacuum) v = c/n (in the media) Formulas c = f.

Slides:



Advertisements
Similar presentations
24.6 Diffraction Huygen’s principle requires that the waves spread out after they pass through slits This spreading out of light from its initial line.
Advertisements

Chapter 9 Light as a Wave.
Chapter 9 Light as a Wave.
Fisica Generale - Alan Giambattista, Betty McCarty Richardson Copyright © 2008 – The McGraw-Hill Companies s.r.l. 1 Chapter 11: Waves Energy Transport.
Types, characteristics, properties
Waves Energy can be transported by transfer of matter. For example by a thrown object. Energy can also be transported by wave motion without the transfer.
Optics 1. 2 The electromagnetic spectrum Visible light make up only a small part of the entire spectrum of electromagnetic waves. Unlike sound waves and.
Chapter 24 Wave Optics.
Chapter 34 The Wave Nature of Light; Interference
WAVES Optics.
Chapter 16 Wave Motion.
Chapter 13 VibrationsandWaves. Hooke’s Law F s = - k x F s = - k x F s is the spring force F s is the spring force k is the spring constant k is the spring.
Chapter 16 Wave Motion.
Chapter 37 Wave Optics. Wave optics is a study concerned with phenomena that cannot be adequately explained by geometric (ray) optics.  Sometimes called.
Announcements HW set 9 due this week; covers Ch 23 and Ch Office hours: My office hours Th 2 -3 pm or make an appointment Come to class April 19.
4.4.1 Wave pulse: a wave pulse is a short wave with no repeated oscillations Progressive wave: a wave that moves through a medium transferring energy as.
Phy107 Fall 06 1 Exam Results Exam: –Exam scores posted on No homework due next week D C BC B AB A.
Waves.
Physics Subject Area Test WAVES LIGHT & OPTICS.
Describe a Wave. Chapter 14 Waves & Energy Transfer.
The wave nature of light Interference Diffraction Polarization
CHAPTER 37 : INTERFERENCE OF LIGHT WAVES
EXAMPLE Young’s double-slit experiment is performed with 589-nm light and a distance of 2.00 m between the slits and the screen. The tenth interference.
AP Physics B Summer Course 年 AP 物理 B 暑假班 M Sittig Ch 23: Waves.
Waves Topic 4.5 Wave Properties. Wave Behaviour v Reflection in one dimension.
Chapter 13 Vibrations and Waves. Hooke’s Law F s = - k x F s is the spring force k is the spring constant It is a measure of the stiffness of the spring.
Phys203 Basic Principles of Contemporary Physics Waves, Optics, and Modern Physics Alexander Dzyubenko
Chapter 17 Waves. Wave Motion Fundamental to physics (as important as particles) Fundamental to physics (as important as particles) A wave is the motion.
Waves and optics formula Velocity equals the product of the frequency and the wavelength Formula: Units Index of refraction of a medium equals the ratio.
Unit 12, Presentation 2. Simple Pendulum  The simple pendulum is another example of simple harmonic motion  The force is the component of the weight.
Chapter 24 Wave Optics. General Physics Review – waves T=1/f period, frequency T=1/f period, frequency v = f velocity, wavelength v = f velocity, wavelength.
Chapter 24: Thin Films Diffraction Diffraction Grating.
Chapter 13 VibrationsandWaves. Hooke’s Law F s = - k x F s = - k x F s is the spring force F s is the spring force k is the spring constant k is the spring.
Waves Topic 4.5 Wave Properties. Wave Behavior  Reflection in one dimension.
1 Light Chapters 36 – 39 2 Wave or Particle? Newton -- particles. In the early 19 th century, Young, Fresnel, and others -- wave. In 1860 Maxwell --
In describing the propagation of light as a wave we need to understand: wavefronts: a surface passing through points of a wave that have the same phase.
Chapter 11:Vibrartions and Waves
Interference Patterns Constructive interference occurs at the center point The two waves travel the same distance –Therefore, they arrive in phase.
Interference Patterns Constructive interference occurs at the center point The two waves travel the same distance –Therefore, they arrive in phase.
Wave Mechanics Physics 1. What is a wave? A wave is: an energy-transferring disturbance moves through a material medium or a vacuum.
Hooke’s Law F s = - k x F s is the spring force k is the spring constant It is a measure of the stiffness of the spring A large k indicates a stiff spring.
Interference in Thin Films, final
Ch 16 Interference. Diffraction is the bending of waves around obstacles or the edges of an opening. Huygen’s Principle - Every point on a wave front.
Light Wave Interference In chapter 14 we discussed interference between mechanical waves. We found that waves only interfere if they are moving in the.
Lecture Nine: Interference of Light Waves: I
Lecture 24 Interference of Light.
Physics 1C Lecture 27A. Interference Treating light as a particle (geometrical optics) helped us to understand how images are formed by lenses and mirrors.
Chapter 38 Diffraction Patterns and Polarization.
Announcements HW set 10 due this week; covers Ch (skip 24.8) and Office hours: Prof. Kumar’s Tea and Cookies 5-6 pm today My office hours.
AP Physics 2 Unit 6 Wave Motion and Geometric Optics.
Wave Optics Light interferes constructively and destructively just as mechanical waves do. However due to the shortness of the wave length (4-7 x
Interference of Light Waves
Lecture 16 Interference Chapter 24.1  24.4 Outline Conditions for Interference Experiments Showing Interference Interference in Thin Films.
Waves. Waves 3 Types of Waves Mechanical Waves: Wave motion that requires a medium (ie. water, sound, slinkies, …) Electromagnetic Waves: No medium is.
Chapter 11 Vibrations and Waves.
Wave are oscillations (repeating disturbance or movement) that transfers energy through matter or space. Wave- energy transfer due to the movement due.
Chapter 15: Wave Motion 15-2 Types of Waves: Transverse and Longitudinal 15-3 Energy Transported by Waves 15-4 Mathematical Representation of a Traveling.
VibrationsandWaves. Ch. 14 examines wave motion and the oscillating, vibrating motion that creates them. This oscillating motion is known as periodic.
Paul G Hewitt Conceptual Physics. Waves Wave: a periodic disturbance in a medium that carries energy, not matter, from one point to another.
Holt Physics Chapter 12 Waves Periodic Motion A repeated motion that is back and forth over the same path.
Chapter 14 Vibrations and Waves. Hooke’s Law F s = - k x F s is the spring force k is the spring constant It is a measure of the stiffness of the spring.
Chapter 24 Wave Optics. Young’s Double Slit Experiment Thomas Young first demonstrated interference in light waves from two sources in Light is.
Chapter 13 Vibrations and Waves. Hooke’s Law F s = - k x F s is the spring force k is the spring constant It is a measure of the stiffness of the spring.
The wave nature of light Interference Diffraction Polarization
Interference of Light Waves
Vibrations and Waves.
Interference of Light Waves
Chapter 13 Vibrations and Waves.
Phys2120 Basic Principles of Contemporary Physics Waves, Optics, and Modern Physics Alexander Dzyubenko © 2014.
Presentation transcript:

University Physics Midterm Exam Overview

16. THE NATURE OF LIGHT Speed of light c = 3x10 8 m/s (in the vacuum) v = c/n (in the media) Formulas c = f =  f = 1/T  (How to memorize? Think about v=d/t.) 

Refraction and Reflection The incident ray, the reflected ray, the refracted ray, and the normal all lie on the same plane What is the normal? How to find angle of incidence and angle of refraction?

Snell’s Law n 1 sin θ 1 = n 2 sin θ 2 θ 1 is the angle of incidence θ 2 is the angle of refraction

As light travels from one medium to another its frequency (f) does not change But the wave speed (v=c/n) and the wavelength ( med = /n) do change

17. THIN LENSES Magnification Thin Lens Equation QuantityPositive “+”Negative “-” s - Object DistanceFront*Back* s’ - Image Distance Back* Real Front* Virtual f - Focal Length (f)Converging “()”Diverging “)(” h – Image HeightUprightInverted

Combination of Thin Lenses

Spherical Mirrors Focal length is determined by the radius of the mirror

Corrective Lenses Nearsighted correction – bring infinity to the far point image distance = - far point (upright virtual image) object distance = ∞ Farsighted correction – bring the close object (accepted 25 cm) to the near point of farsighted image distance = - near point (upright virtual image) object distance = 25 cm Power of the Lens P=1/f (in diopters or m -1 )

18. Wave Motion A wave is the motion of a disturbance Mechanical waves require Some source of disturbance A medium that can be disturbed Some physical connection between or mechanism though which adjacent portions of the medium influence each other All waves carry energy and momentum

Types of Waves – Traveling Waves Flip one end of a long rope that is under tension and fixed at one end The pulse travels to the right with a definite speed A disturbance of this type is called a traveling wave

Types of Waves – Transverse In a transverse wave, each element that is disturbed moves in a direction perpendicular to the wave motion

Types of Waves – Longitudinal In a longitudinal wave, the elements of the medium undergo displacements parallel to the motion of the wave A longitudinal wave is also called a compression wave

Speed of a Wave v = λ ƒ Is derived from the basic speed equation of distance/time This is a general equation that can be applied to many types of waves

Speed of a Wave on a String The speed on a wave stretched under some tension, F  is called the linear density The speed depends only upon the properties of the medium through which the disturbance travels

Waveform – A Picture of a Wave The brown curve is a “snapshot” of the wave at some instant in time The blue curve is later in time The high points are crests of the wave The low points are troughs of the wave

Interference of Sound Waves Sound waves interfere Constructive interference occurs when the path difference between two waves’ motion is zero or some integer multiple of wavelengths path difference = mλ Destructive interference occurs when the path difference between two waves’ motion is an odd half wavelength path difference = (m + ½)λ

Mathematical Representation It can be derived by comparing the factors of x and t, that and Dividing  and k gives v, that is A wave moves to the left with velocity v and wave length, can be described using

Doppler Effect If the source is moving relative to the observer The doppler effect is the change in frequency and wavelength of a wave that is perceived by an observer when the source and/or the observer are moving relative to each other.

19. INTERFERENCE Light waves interfere with each other much like mechanical waves do Constructive interference occurs when the paths of the two waves differ by an integer number of wavelengths (  x=m ) Destructive interference occurs when the paths of the two waves differ by a half-integer number of wavelengths (  x=(m+1/2) )

Interference Equations The difference in path difference can be found as  x = d sinθ For bright fringes, d sinθ bright = mλ, where m = 0, ±1, ±2, … For dark fringes, d sinθ dark = (m + ½) λ, where m = 0, ±1, ±2, … The positions of the fringes can be measured vertically from the center maximum, y  L sin θ (the approximation for little θ)

Single Slit Diffraction A single slit placed between a distant light source and a screen produces a diffraction pattern It will have a broader, intense central band The central band will be flanked by a series of narrower, less intense dark and bright bands

Single Slit Diffraction, 2 The light from one portion of the slit can interfere with light from another portion The resultant intensity on the screen depends on the direction θ

Single Slit Diffraction, 3 The general features of the intensity distribution are shown Destructive interference occurs for a single slit of width a when asinθ dark = mλ m =  1,  2,  3, …

Interference in Thin Films The interference is due to the interaction of the waves reflected from both surfaces of the film Be sure to include two effects when analyzing the interference pattern from a thin film Path length Phase change

Facts to Remember The wave makes a “round trip” in a film of thickness t, causing a path difference 2nt, where n is the refractive index of the thin film Each reflection from a medium with higher n adds a half wavelength /2 to the original path The path difference is  x = x 2  x 1 For constructive interference  x = m For destructive interference  x = (m+1/2) where m = 0, 1, 2, … Path change x 1 = /2 Path change x 2 = 2nt

Thin Film Summary Low  x = 2nt  /2 n x 1 = /2 x 2 = 2nt High Low  x = 2nt n x 1 = 0 p 2 = 2nt Low High  x = 2nt n x 1 = /2 x 2 = 2nt+ /2 High  x = 2nt + /2 n x 1 = 0 x 2 = 2nt + /2 Thinnest film leads to constructive 2nt = destructive 2nt = /2 Thinnest film leads to constructive 2nt =  destructive 2nt =

20. COULOMB’S LAW Coulomb shows that an electrical force has the following properties: It is along the line joining the two point charges. It is attractive if the charges are of opposite signs and repulsive if the charges have the same signs Mathematically, k e is called the Coulomb Constant k e = 9.0 x 10 9 N m 2 /C 2

Vector Nature of Electric Forces The like charges produce a repulsive force between them The force on q 1 is equal in magnitude and opposite in direction to the force on q 2

Vector Nature of Forces, cont. The unlike charges produce a attractive force between them The force on q 1 is equal in magnitude and opposite in direction to the force on q 2

The Superposition Principle The resultant force on any one charge equals the vector sum of the forces exerted by the other individual charges that are present. Remember to add the forces as vectors

Superposition Principle Example The force exerted by q 1 on q 3 is The force exerted by q 2 on q 3 is The total force exerted on q 3 is the vector sum of and