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Introduction to Waves. The location of energy sources may be different than where they are needed. The energy must be transferred from one location to another by some means such as……. Movement of Material. Ie. Projectiles in flight, wind, etc.
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The location of energy sources may be different than where they are needed. • The energy must be transferred from one location to another by some means such as……
Movement of Material • Ie. Projectiles in flight, wind, etc. • When a ball hits a window, the glass is shattered by energy transferred from the ball during impact.
Thermal Convection • Heat energy is transferred by thermal convection. This is the movement of quantities of heated gas or liquid between two locations.
Waves • Ie. Sound waves, light waves, water waves, etc. The ideas and language used to describe waves are the same, regardless of the kinds of waves involved.
What is a wave? • The basic concept in the use of the term wave is that the wave involves some quantity or disturbance that changes in magnitude with respect to time at a given location and changes in magnitude from place to place at a given time. • A wave is a disturbance that propagates through a medium or space (vacuum).
Some waves are electromagnetic waves • Electromagnetic waves can travel through a material or through a vacuum. • Examples include visible light, microwaves, radio waves, x-rays, infrared rays and ultraviolet waves. • V = 3.00 x 108 m/s in air or a vacuum
Some waves are mechanical waves • Mechanical waves require a material medium for their propagation (movement). • Sound waves, ocean waves, and earthquakes are mechanical waves. • Mechanical waves can be transverse, longitudinal, or surface waves.
Transverse Waves • A transverse wave is a wave in which the vibrations are at right angles to the direction of propagation. • http://surendranath.tripod.com/Applets/Waves/Twave01/Twave01Applet.html
Longitudinal Waves • A longitudinal wave is a wave in which the vibrations are parallel to the direction of propagation of the wave. • http://www.glenbrook.k12.il.us/GBSSCI/PHYS/mmedia/waves/lw.html
Surface Waves • Surface waves such as water waves combine longitudinal and transverse wave movement. • http://www.classzone.com/books/earth_science/terc/content/visualizations/es1604/es1604page01.cfm?chapter_no=visualization
Elastic medium Disturbance Pulse Crest Trough Compression rarefaction Speed Frequency Period Wavelength Amplitude Phase Define the following wave terms