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What makes sound?	Vibrations		phys-light-sound-waves
Can sound travel in space?	No; it needs matter to travel through		phys-light-sound-waves
Does sound travel faster in air or water?	Water		phys-light-sound-waves
Sound travels fastest through	Solids		phys-light-sound-waves
Pitch	How high or low a sound is		phys-light-sound-waves
What determines pitch?	Frequency		phys-light-sound-waves
Volume (loudness)	How strong a sound is; depends on amplitude		phys-light-sound-waves
Unit of loudness	Decibel		phys-light-sound-waves
Echo	A sound that bounces off a surface and comes back		phys-light-sound-waves
Ultrasound	Sound with frequency too high for humans to hear		phys-light-sound-waves
Infrasound	Sound with frequency too low for humans to hear		phys-light-sound-waves
Range of human hearing, roughly	20 to 20,000 hertz		phys-light-sound-waves
Sonar	Using sound echoes to find objects underwater		phys-light-sound-waves
Echolocation	Animals such as bats and dolphins using echoes to find things		phys-light-sound-waves
Speed of sound in air, roughly	343 meters per second		phys-light-sound-waves
Sonic boom	A loud noise made when something travels faster than sound		phys-light-sound-waves
Speed of light	About 300,000 kilometers per second		phys-light-sound-waves
Why do we see lightning before we hear thunder?	Light travels much faster than sound		phys-light-sound-waves
Light travels in	Straight lines		phys-light-sound-waves
Reflection of light	Light bouncing off a surface		phys-light-sound-waves
Refraction of light	Light bending when it enters a new material		phys-light-sound-waves
What does a prism do?	Splits white light into a rainbow of colors		phys-light-sound-waves
Colors of the rainbow in order	Red, orange, yellow, green, blue, indigo, violet		phys-light-sound-waves
Which color of visible light has the longest wavelength?	Red		phys-light-sound-waves
Which color has the shortest wavelength?	Violet		phys-light-sound-waves
Transparent	Lets light pass through clearly		phys-light-sound-waves
Translucent	Lets some light through but scatters it		phys-light-sound-waves
Opaque	Blocks light		phys-light-sound-waves
Shadow	A dark area where an object blocks light		phys-light-sound-waves
Convex lens	A lens thicker in the middle; makes light converge		phys-light-sound-waves
Concave lens	A lens thinner in the middle; makes light spread out		phys-light-sound-waves
Plane mirror	A flat mirror that forms an image the same size as the object		phys-light-sound-waves
Concave mirror	A mirror curved inward, like the inside of a spoon		phys-light-sound-waves
Convex mirror	A mirror curved outward, used as a car side mirror		phys-light-sound-waves
Primary colors of light	Red, green and blue		phys-light-sound-waves
Primary colors of paint (traditional)	Red, yellow and blue		phys-light-sound-waves
Why is the sky blue?	Air scatters blue light more than other colors		phys-light-sound-waves
Why are sunsets red?	Light passes through more air, scattering the blue away		phys-light-sound-waves
Electromagnetic spectrum order, long to short wavelength	Radio, microwave, infrared, visible, ultraviolet, X-ray, gamma ray		phys-light-sound-waves
Radio waves are used for	Radio, TV and phones		phys-light-sound-waves
Microwaves are used for	Cooking and communications		phys-light-sound-waves
Infrared is felt as	Heat		phys-light-sound-waves
Ultraviolet light	Causes sunburn and tanning		phys-light-sound-waves
X-rays are used for	Seeing bones and inside objects		phys-light-sound-waves
Gamma rays	The highest-energy waves		phys-light-sound-waves
Laser	A narrow beam of light of one wavelength		phys-light-sound-waves
Fiber optics	Thin glass fibers that carry light signals		phys-light-sound-waves
Total internal reflection	Light bouncing entirely inside a material like glass or water		phys-light-sound-waves
Mirage	An image caused by light bending in hot air		phys-light-sound-waves
Wave	A disturbance that carries energy		phys-light-sound-waves
Crest	The highest point of a wave		phys-light-sound-waves
Trough	The lowest point of a wave		phys-light-sound-waves
Amplitude	The height of a wave from rest position		phys-light-sound-waves
Wavelength	Distance between two crests		phys-light-sound-waves
Frequency	Waves per second		phys-light-sound-waves
Medium	The material a wave travels through		phys-light-sound-waves
Resonance	A strong vibration when something is pushed at its natural frequency		phys-light-sound-waves
Interference	Waves combining to be bigger or smaller		phys-light-sound-waves
Doppler effect	A siren sounds higher as it approaches and lower as it leaves		phys-light-sound-waves