Key areas Conditions for constructive and destructive interference.

Slides:



Advertisements
Similar presentations
Mechanical Waves and Sound
Advertisements

Ripple Tank Summary.
Section 3 - The Behavior of Waves
Unit 7 Waves Chapter 11 Pages
Types, characteristics, properties
Waves!.
Waves and Energy Transfer Chapter 15 pages
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.
Interference Physics 202 Professor Lee Carkner Lecture 24.
Interference Physics 202 Professor Lee Carkner Lecture 24.
Introduction to Waves Auto slide change for this page, WAIT…..
Wave Behavior.
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.
Chapter 20 Preview Section 1 The Nature of Waves
Waves Chapter 14 Notes. What is a Wave? / A wave is a periodic disturbance of matter (solid, liquid, or gas) / Examples include: / Sound / Light / Ocean.
Waves. The Nature of Waves What is a mechanical wave?  A wave is a repeating disturbance or movement that transfers energy through matter or space 
Wave Characteristics. Terms to Review Parts of a Wave – Crest – Trough – Pulse – Amplitude – Wavelength – Frequency – Period Types of Waves – Mechanical.
Diagram of a wave WAVELENGTH PEAK OR CREST TROUGH AMPLITUDE All waves are caused by vibrations.
Transverse or longitudinal waves transport energy from one point to another. Each particle in the medium vibrates or oscillates, and disturbs the neighbouring.
Goal: To understand light Objectives: 1)To learn about the Properties of light 2)To learn about Diffraction 3)To learn about Polarization 4)To learn how.
INTERFERENCE DIVISION OF AMPLITUDE. Interference of waves occurs when waves overlap. There are two ways to produce an interference pattern for light:
What is a wave?  A wave is a transfer of energy from one point to another via a traveling disturbance  A wave is characterized by its wavelength, frequency,
Lesson Objectives By the end of this lesson, you will be able to: State the different types of waves and the difference between them Describe the diffraction.
Waves and Energy Transfer
Surface Waves. Surface Wave A wave that has characteristics of both transverse and longitudinal waves (Ocean Waves). Surface Wave Applet.
Chapter 9: Introduction to Waves
Higher Physics – Unit Waves. a a λ λ crest trough Wave Theory All waves transmit energy. The energy of a wave depends on its amplitude. a = amplitude.
Wave Characteristics and Speed. a traveling disturbance that carries energy through matter or space matter moves horizontally or vertically just a little,
11/24/08 Warm Up Draw a wave and label the crest and trough.
Chapter 1 Section 3 t-catch-the-physics-of-waves.html.
Wave are oscillations (repeating disturbance or movement) that transfers energy through matter or space. Wave- energy transfer due to the movement due.
Ch. 15 What are waves? -A wave is a traveling disturbance that carries energy from one place to another.
Chapter 20 Waves.
DIFFRACTION & REFRACTION OF WAVES. DIFFRACTION OF WAVES Diffraction: A change in direction or bending of waves as they pass through an opening or around.
Lesson 3: Wave Interactions. Interaction of Waves with Matter Absorption: is the transfer of energy by a wave to the medium through which it travels Transmission:
1 Recognize that all waves transfer energy. R e l a t e f r e q u e n c y & w a v e l e n g t h t o t h e e n e r g y o f d i f f e r e n t t y p e s.
Chapter 22 Section 1 The Nature of Waves Question of the Day What do you think of when you hear the word WAVE? Write a brief description on your paper.
Chapter 22 The Energy of Waves Preview Section 1 The Nature of WavesThe Nature of Waves Section 2 Properties of WavesProperties of Waves Section 3 Wave.
Statement P4.4 Wave CharacteristicsWaves (mechanical and electromagnetic) are described by their wavelength, amplitude, frequency, and speed. P4.4A Describe.
Wave Definition: A disturbance that transfers energy from place to place. A medium, a medium is the material through which a wave travels. A medium can.
UNIVERSITY OF GUYANA FACULTY OF NATURAL SCIENCES DEPART. OF MATH, PHYS & STATS PHY 110 – PHYSICS FOR ENGINEERS LECTURE 6 (THURSDAY, OCTOBER 6, 2011) 1.
Revision Tips – Key areas Final Countdown
Advanced Higher Physics Interference
Waves & Energy Transfer
Waves Waves are “a disturbance that transfers energy”.
Waves What are waves?.
Wave Properties.
Harmonic Motion and Mechanical Waves
Ch Wave Interactions OBJECTIVES
Interactions of Waves Chapter 15 Section 3.
Wave Interactions Chapter 14-3.
15.3 Interactions of waves Key concepts: How do reflection, refraction, and diffraction change a wave’s direction? What are the different types of interference?
Wave Interaction Chapter 1.3.
Wave Interactions.
Wave a disturbance that propagates through a material medium or space.
Wave a disturbance that propagates through a material medium or space.
Wave Properties & Interactions
Waves and their properties
Wave a disturbance that propagates through a material medium or space.
Oscillations and Waves
Chapter 13 Waves and Sound.
Unit 7 Waves Chapter 11 Pages
P. Sci. Unit 5 Waves Cont..
Chapter 13 Waves and Sound.
Unit 2 Particles and Waves Interference
Waves What are waves? Ms. P. IA.
Wave notes 11.5 and 11.6.
Lets review what we have learned…..
WAVES.
Presentation transcript:

Key areas Conditions for constructive and destructive interference. Constructive and destructive interference in terms of phase between two waves. Coherent waves have a constant phase relationship and have the same frequency, wavelength and velocity. Interference of waves using two coherent sources.

What we will do today: Revise some basic wave definitions. Use correctly the terms “in phase”, “out of phase” and “coherent” when applied to waves. Explain the meaning of “constructive interference” and “destructive interference”. State that interference is a test for a wave. State that reflection, refraction, diffraction and interference are characteristic behaviours of all types of waves.

Waves Revision

Wave Characteristics Period = 1 / frequency Period, T: the time taken for one complete wave to pass a point (s). Frequency = 1 / period Frequency, f: the number of waves per second (Hz)

The frequency of a wave is the same as the frequency of its source. (Provided the source doesn’t move).

The energy of a wave depends on its amplitude (a).

2007

Wave Equation v = f λ Wavelength, λ: the length of one wave (m). Frequency, f: the number of waves per second (Hz). Wave speed, v: the speed of a wave (ms-1) They are all related by the equation: v = f λ

Interference and Path Difference

Phase Two waves in phase. Maximum and minimum points on the wave occur at the same time.

Two waves completely out of phase. The maximum of one wave occurs at the minimum of the other and vice versa.

Coherent Sources If waves coming from two sources have the same frequency, wavelength and velocity and are in phase, then the two sources are coherent. They will also have the same amplitude. Coherent light is light which has no phase difference.

CfE Specimen Paper

Wave Characteristics Reflection, refraction, diffraction and interference are characteristic behaviours of all types of waves. We have previously covered the first three.

1. Reflection Waves reflect off a surface. The angle of incidence (incoming angle) is equal to the angle of reflection (outgoing angle). i = r

2. Refraction Waves change speed usually with a change in direction when passing from one medium to another (eg air to water).

3. Diffraction Waves ‘spread out’ round corners. When passing through a gap the waves appear to curve. If the gap is similar to the wavelength then circular wavefronts are produced.

Interference When two sets of waves meet, they combine to produce a new pattern. The new pattern depends on the original wavelengths, amplitudes etc. Waves combine in one of two ways: Constructive Interference. Destructive Interference Interference is the test for a wave.

2012 Revised

Answer Refer to previous lesson on light travelling as particle in photons. Discuss how light produces interference so also acts as a wave. Conclusion – light is both

Constructive Interference Two sets of waves meet in phase. Two crests meet or two troughs meet to produce a larger crest or trough. + =

Destructive Interference = +

Two sets of waves meet completely out of phase (i. e Two sets of waves meet completely out of phase (i.e. 180º out of phase). A crest meets a trough and combine to cancel each other out and produce no wave at that point. Note that if waves are not of equal amplitude, then complete cancelling does not occur.

Path Difference An interference pattern is more easily explained in terms of path difference. Consider an interference pattern produced by two coherent wave sources as shown below.

The two wave trains travel equal distances (AC = BC). i.e. There is no path difference. C B Wave Source Double Slit Screen

The two wave trains travel different distances. There is a path difference. B Wave Source Path Difference Double Slit Screen