Unit 3 Lesson 2 Properties of Waves Copyright

Unit 3 Lesson 2 Properties of Waves Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 3 Lesson 2 Properties of Waves Florida Benchmarks • SC. 7. P. 10. 3 Recognize that light waves, sound waves, and other waves move at different speeds in different materials. • MA. 6. A. 3. 6 Construct and analyze tables, graphs, and equations to describe linear functions and other simple relations using both common language and algebraic notation. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 3 Lesson 2 Properties of Waves Florida Benchmarks • LA. 6. 4. 2. 2 The student will record information (e. g. , observations, notes, lists, charts, legends) related to a topic, including visual aids to organize and record information and include a list of sources used. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 3 Lesson 2 Properties of Waves Amp It UP! How can we describe a wave? • Waves can be described by basic properties. • In a transverse wave, there are special terms for the maximum displacement of particles in the wave. • The highest points are crests; the lowest points are troughs. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 3 Lesson 2 Properties of Waves How can we describe a wave? • A wave’s amplitude is a measure of how far particles in the medium move away from their normal rest position. • Wavelength is the distance over which the wave’s shape repeats. • Wavelength is the distance from any point on a wave to an identical point later on the wave. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 3 Lesson 2 Properties of Waves How can we describe a wave? • What is the wavelength of this wave? What is the wave’s amplitude? Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 3 Lesson 2 Properties of Waves How can we describe a wave? • Another property is wave period, the time required for one wavelength to pass a given point. • Frequency is also a way to express how far apart waves are in time. It is the number of crests that pass a point in a certain amount of time. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 3 Lesson 2 Properties of Waves How can we describe a wave? • Frequency is measured in hertz (Hz). One hertz equals one wavelength per second. • Frequency is the inverse of period. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 3 Lesson 2 Properties of Waves Amp It Down What affects the energy of a wave? • Some waves carry more energy than others. • Friction has a dampening effect on waves, meaning it causes them to lose energy. • The amount of energy a mechanical wave carries determines its amplitude. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 3 Lesson 2 Properties of Waves What affects the energy of a wave? • The amplitude of a sound wave corresponds to its volume. • In an electromagnetic (EM) wave, energy depends on frequency as well as amplitude. • High-frequency waves carry more energy than low -frequency waves. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 3 Lesson 2 Properties of Waves What affects the energy of a wave? • Many waves spread out in circles or spheres, called wave fronts. • As the circle expands, there is less energy available on the wavefront. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 3 Lesson 2 Properties of Waves A Happy Medium What determines the speed of a wave? • Wave speed, or the speed at which waves travel, depends on the properties of the medium. • Waves tend to travel slower in a denser medium. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 3 Lesson 2 Properties of Waves A Happy Medium What determines the speed of a wave? • In gases, wave speed is higher in higher temperatures. • All electromagnetic waves travel at the same speed in empty space, but they travel more slowly through a denser medium. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 3 Lesson 2 Properties of Waves What determines the speed of a wave? • Wave speed can be calculated from frequency and wavelength. • Speed is a distance divided by time. Copyright © Houghton Mifflin Harcourt Publishing Company

Unit 3 Lesson 2 Properties of Waves What determines the speed of a wave? • Wave speed is a wavelength divided by wave period. • This relationship can be combined with the relationship between wavelength and frequency. • The wavelength is equal to the wave speed divided by its frequency. Copyright © Houghton Mifflin Harcourt Publishing Company