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Explore the concept of waves and their categories, such as mechanical and electromagnetic waves. Learn how waves carry energy and the various interactions they have, including reflection, refraction, and diffraction. Discover the properties of sound waves and how they travel through a medium.
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What is a wave? an oscillation (repetitive movement) that travels from one place to another
2 Categories of Waves Mechanical Waves Electromagnetic Waves Need a medium (gas, liquid or solids) to travel through Example: Sound Waves • Do not need a medium (vacuum) • Example: Light Waves
WAVES CARRY ENERGY! Water Waves and Energy
Electromagnetic Spectrum name for the range of electromagnetic waves when placed in order of increasing frequency (ENERGY)
EM Spectrum Raging (radio) Martians (microwave) Invaded (infrared) Venus (visible light) Using (ultraviolet) Xray (x-ray) Guns (gamma)
GPS-video Measure the time it takes a radio wave to travel from several satellite to the receiver, determining the distance of each satellite
RADIOS Radios pick up radio waves through an antenna and convert it to sound waves Each radio station broadcasts to a different frequency
MICROWAVES Waves transfer energy to the food causing them to vibrate which turns into energy in the form of heat to the food
INFRARED Warm objects give off more heat energy, so temperatures can be calculated via infrared radiation. iphone
VISIBLE LIGHT Electromagnetic waves that we can see Red light = longest wavelength Purple light = shortest wave length
UV RAYS Carry more energy than visible light -Sun - Kill bacteria (sterilize) -Causes skin to make Vitamin D
X-RAYS Carry a great amount of energy and can penetrate most matter Bones and teeth absorb x-rays. (Light part is where the x-ray was absorbed)
GAMMA RAYS GREATEST amount of energy • used in radiation treatment to kill cancer cells • can be very harmful if not used correctly • exploding nuclear weapons emit gamma rays
PARTS OF A WAVE Crest Trough High point of the wave Low point of the wave
PARTS OF A WAVE Frequency- how often a wave occurs in 1 sec
PARTS OF A WAVE Amplitude How high a wave travels from the origin
PARTS OF A WAVE Wavelength distance from any point on a wave to the same point on the next cycle of the wave.
Wavelength Speed Period time it takes to make one complete cycle (ex. Crest to crest)
Lower Frequency? Higher Frequency? Longer Wavelength? How are wavelength and frequency related?
Frequency and Wavelength Frequency and Wavelength inverse relationship Increase Frequency → Decrease Wavelength Decrease Frequency → Increase Wavelength
Transverse Waves Waves that move up and down
Longitudinal/Compression Waves Wave moves side to side
REFLECTION Bouncing back of a wave • Sound echos • Light images in mirrors
REFRACTION Bending of a wave caused by the change of mediums
DIFFRACTION Bending of a wave around the edge of an object • Water waves bend around islands • Water waves pass through a slit and spread out
SOUND WAVES Energy is transferred from particle to particle through matter
Properties of Sound Pitch: Loudness: how high or low a sound is (determined by the wave’s frequency) characteristic of sound (determined by the wave’s amplitude)
Sound Makes the Air Vibrate ¡Sound MUST travel through a medium You cannot hear sound in outer space because there is no air or other matter to carry sound vibrations.
Like an Echo Song Animals and Sound