Download Electromagnetic Waves Mechanical Waves All W aves

Electromagnetic Waves
All Waves
• Have wave vibrations which move up and down (transverse waves)
• Can travel through empty space as well as through a medium (such as the atmosphere)
• Form a spectrum with separate parts: radio waves, microwaves, infrared, visible light, ultraviolet, x rays, gamma rays
• Vary in wavelength: (longest) radio waves, microwaves, infrared, visible light, ultraviolet, x rays, gamma rays (shortest)
• Vary in frequency: (lowest) radio waves, microwaves, infrared, visible light, ultraviolet, x rays, gamma rays (highest)
• Waves are vibrations created by an energy source (such as the Sun); waves move from one place to another
• Waves have specific shapes -- tops (crests) and bottoms (troughs), length (wavelength) and height (amplitude)
• The number of waves that pass a particular point can be counted; the number of vibrations per second (frequency) can be
calculated; and the time it takes for one wave to pass (period) can also be measured
• Every instant of your life you interact with one type of wave or another; some of these interactions are essential (use of light
waves to see and sound waves to hear); others form part of civilized life (cooking food with microwaves, communicating via
radio waves, imaging internal organs using ultrasound or x rays)
• Have wave vibrations which move back and forth (longitudinal waves)
• Can only travel through a medium (such as the air, or a body of water, or a solid object)
• Travel faster through liquids than gases, and fastest through solids
• One type, water waves, only travel through water and are created by wind, animals, and machines
• Another type, seismic waves, only travel through the earth and are created by movements of the Earth’s crust
• A third type, sound waves, can travel through gas, liquid, and solid and are created by many sources
Mechanical Waves