17 1 Mechanical Waves Chapter 17 Mechanical Waves

17. 1 Mechanical Waves Chapter 17 Mechanical Waves and Sound Ocean waves, like all mechanical waves, carry energy through a medium

17. 1 Mechanical Waves Key Concepts • What causes mechanical waves? • What are three main types of mechanical waves?

17. 1 Mechanical Waves What Are Mechanical Waves? A mechanical wave is a ______ in matter disturbance energy that carries _____ from one place to another. • Recall that energy is the ability to do _____ work • The material through which a wave moves is called a _________ medium • Solids, liquids, and gases can act as mediums

17. 1 Mechanical Waves water • In a wave pool, ________ is the medium. • You can see the effects of a wave’s energy when the wave ______ people in the water (work) lifts

17. 1 Mechanical Waves What Are Mechanical Waves? A mechanical wave is created when some source of energy causes a ________ to travel vibration through a medium. • A vibration is a repeating _____-and-_____ back forth motion. • When you shake a rope, you add energy at _______ one end…the wave that results is a along vibration that carries energy _______ the rope

17. 1 Mechanical Waves Types of Mechanical Waves The three main types of mechanical waves are… transverse ______________________ waves longitudinal ____________waves surface Mechanical waves are classified by the ____ way ________ through a medium. they move

17. 1 Mechanical Waves Types of Mechanical Waves • The highest point of the wave is the _______. crest trough • The lowest point of the wave is the _______ down • A single point vibrates ______ between a up and _____ crest and trough. Crest Rest position Direction of vibration Rest position Trough

17. 1 Mechanical Waves Types of Mechanical Waves A transverse wave causes the medium to vibrate in a direction right angle _________ or in a _______ to the perpendicular direction in which the wave travels. Direction of wave Crest The wave carries energy from _______, in a direction left to right perpendicular to the _________ motion of the wave. up and down

17. 1 Mechanical Waves Types of Mechanical Waves A good example of a transverse wave is shaking sand off of a beach blanket You shake the blanket __________ up and down The transverse wave moves _______ the along blanket

17. 1 Mechanical Waves Types of Mechanical Waves Longitudinal Waves In a spring toy, the wave carries energy _______the spring. along • An area where the particles in a medium are spaced close together is called a ____________ compression • An area where the particles in a medium are spread out is called a ____________ rarefaction

17. 1 Mechanical Waves Types of Mechanical Waves A. A compression move starts to _______ along the spring. B. A rarefaction _______ follows the compression along the spring. Compression Push Pull Rarefaction Compression Rest position Direction of wave

17. 1 Mechanical Waves Types of Mechanical Waves A longitudinal wave is a wave in which the vibration of the medium is ________ parallel to the direction the wave travels.

17. 1 Mechanical Waves • Another type of longitudinal wave is P wave or _______ called a ____ primary wave – Caused by earthquakes – Since P waves can travel through the earth, map scientists use these waves to _______ Earth’s unseen interior

17. 1 Mechanical Waves Types of Mechanical Waves Surface Waves Ocean waves are the most familiar kind of _______ surface waves. A surface wave is a wave that travels along a surface ________ two media. between

17. 1 Mechanical Waves Types of Mechanical Waves The ocean wave shown travels at the surface between _____ air and ____ water The floating fishing bobber helps to visualize the motion of the medium as the wave moves ____________ energy from left to right Wave direction

17. 1 Mechanical Waves Types of Mechanical Waves When a crest passes the bobber, up the bobber moves ____ When a trough passes the bobber, the bobber moves ______ down This up and down motion is similar to a _________ transverse wave Wave direction

17. 1 Mechanical Waves Types of Mechanical Waves The surface wave also pushes the back bobber ______ and _______ like a longitudinal forth wave When these two motions combine ________ (up-down) and (back-forth) the bobber ends up moving in a ________ circle Wave direction

17. 1 Mechanical Waves Types of Mechanical Waves Oceans waves behave differently near the shore friction because _______ with the shore slows down the _______ of the wave bottom

17. 1 Mechanical Waves Assessment Questions 1. A mechanical wave carries energy from one place to another through the a. b. c. d. physical transfer of matter. interaction of electromagnetic fields. phase changes of a medium. vibration of a medium.

17. 1 Mechanical Waves Assessment Questions 2. In what type of wave is the vibration of the medium only parallel to the direction in which the wave travels? a. b. c. d. transverse wave longitudinal wave surface wave rarefaction

17. 1 Mechanical Waves Assessment Questions 3. As a surface wave travels across water, molecules of water move in a circular pattern. True False