Waves
1. Radio Waves 2. Microwaves 3. Infrared Rays 4. Visible Light 5. Ultraviolet Light 6. X-rays 7. Gamma Rays
1. nv~wide range, longest wl lowest freq, ex: radio, tv, communicaton 2. nv~shorter wl higher freq, ex: microwave, radar 3. nv~thermal energy, shorter wl higher freq, depend on temp, ex: sun, 4. v~narrow range of shorter wl higher freq, white light: (l)ROY G. BiV(s) 5. nv~shorter wl higher freq, affects body, not all reaches earth, florescent lights 6. nv~shortest wl highest freq, pass through material, x-ray 7. nv~shortest wl highest freq, highest amount of energy, penetrates most material, kill cancer cells
Light Trasmission
The passing of light through matter ~light can be reflected, transmitted, or absourbed ~ how an object can transmit light: opaque, translucent, transparent
Surface Waves
~A combination of Transverse and Longitudinal ~Occur between two media ~Up and down with a back and forth motion creates a circle motion
Lenses
~A lens is a transparent object that forms an image by refracting or bending light. ~Cameras, telescopes and movie projectors all use lenses to create images
Convex Lens
~A lens that is thicker in the middle than at the edges. ~Used to MAGNIFY things ~Used in magnifying glasses, camera lenses and some eyeglasses. ~Used to correct farsightedness
Concave Lens
~A lens that is thinner in the middle than at the edges ~Causes light waves to bend away from each other ~Used in microscopes, eyeglasses and some telescopes ~Used to correct nearsightedness
Convex Mirror
~A mirror that curves outward ~It produces an image that is right side up and smaller than the original. ~Useful because they can make images of large areas.
Plane Mirror
~A mirror that has a flat surface (like your bathroom mirror!) ~The image is right side up and the same size as the actual object. The only difference is that it appears backwards! ~The image appears to be the same distance from the mirror, just on the other side!
Concave Mirror
~A mirror that is curved inward. ~Can create a larger or smaller image ~The image will appear upside down ~Make-up mirror
Waves
~A wave is a movement of energy from a vibrating source outward ~ Any disturbance that transmits energy through matter or empty space ~A wave is caused by a disturbance in a solid, liquid, or gas as energy is transmitted through a medium. ~Waves carry energy from one place to another
Color Addition
~Combining the colors of light ~As more colors of light come together the object appears lighter and lighter ~white light is the combination of all colors
Density
~Density affects the speed of sound when considering mediums that are the same state or phase of matter ~The less dense the medium, the faster the sound; ~The more dense the medium, the slower the sound
Frequency of Sound
~Frequency refers to the number of waves that pass a point in a second; ~The frequency of sound waves indicates the pitch (how high or low) ~The lower the frequency, the lower the pitch ~The higher the frequency, the higher the pitch the sound has.
Wave Speed
~How far a wave travels in one unit of time ~Speed = wavelength x frequency m/s = m x Hz (waves/sec) ~The type of medium will affect wave speed ~For example, sound travels faster in different solids than gases; light travels through water slower than through air
Elasticity
~How fast particles move back to their rest position after disturbance passes though ~Sound travels faster in a more elastic medium; ~Fastest in solids, slowest in gases ~Speed of sound in the ground is four times faster than in air!
Ray
~It is an arrow that we use to show the path of a light wave
Opaque
~Opaque matter does NOT transmit light ~We cannot see things through opaque matter ~metal
Color
~Our eyes recognize each wavelength of light as a different color OPAQUE: By the color of light that the object reflects, all other colors are absorbed TRANSLUCENT/TRANSPARENT:By the color of light that they TRANSMIT, all others are absorbed as they pass through the material.
Echolocation
~Process in which animals use reflected sound waves to determine the distance/location of objects
Sound
~Sound travels as a longitudinal wave ~Energy from a vibration is carried through the medium as the molecules of the medium move back and forth as the disturbance goes by ~You hear the sound when (and if) the disturbance reaches the medium near your ear
Temperature
~Sound travels slower at lower temperatures ~Sound travels faster at higher temperatures
Resonance
~Standing waves - those that appear to be still; actually a wave and its reflection experiencing interference as they travel; this occurs a medium's "resonant frequency." ~Resonance occurs when an object that is vibrating at or near another objects natural (resonant) frequency causes that other object/medium to vibrate
Amplitude of Sound
~The amplitude of a sound wave indicates the energy carried by the wave ~The higher the amplitude, the more intense the sound, or the more loud the sound seems ~intensity=how loud a sound or how much energy it is carrying ~loudness measured in decibels (dB)
The Doppler Effect
~The apparent change in frequency as the wave source moves in relation to the listener ~This is heard as a change in pitch
Refraction of Light
~The bending of light waves as they change mediums due to a change in speed
Diffraction
~The bending of waves around the edge of a barrier ~When a wave passes through or around a barrier it bends and spreads out ~amount of diffraction of a wave depends on its wavelength and the size of the barrier ~sound waves have long wavelengths and are able to diffract around corners unlike light waves ~None of the properties of the wave are changed with diffraction ~The wavelength, frequency and speed are the same before and after the diffraction ~Again, like with reflection, the only change is in the direction of the wave
Wavelength
~The distance between two corresponding parts of a wave ~Shorter wavelength=more energy! ~Crest to crest or Trough to trough ~Compression to compression or rarefaction to rarefaction
Amplitude
~The maximum distance the particles of the medium carrying the wave move away from the rest position; ~Corresponds to the amount of energy in the wave ~Higher amplitude = more energy
Color Subtraction
~The mixing of pigments which causes more colors to be absorbed. ~As more pigments are added objects to appear darker ~Pigment: material that gives a substance its color by determining which wavelength of light it will reflect.
Frequency
~The number of complete waves that pass a given point in a certain amount of time ~Higher frequency=more energy ~The number of vibrations in a second ~Measured in the Hertz (Hz) ~1 Hz = 1 wave per second
Speed of Sound
~The speed of sound is dependent upon the properties of the medium through which it travels; those properties include: Temperature, Elasticity, Density... ~Also, sound travels fastest in solids than liquids or gases and cannot travel through a vacuum!
Transparent
~This material easily transmits light ~allows light to pass through with little interference ~You can see objects clearly through transparent material ~glass
Translucent
~Translucent objects transmit some light and scatter the rest ~transmits light but not an image ~You can't see clearly through this material, objects on the other side appear blurry ~wax paper
Electromagnetic Waves
~Waves that do not require a medium ~Can travel with or without a medium ~Light, radio, x-rays, microwaves..... ~changing electric and magnetic fields that vibrate at right angles to each other
Transverse Waves
~Waves that move the medium at right angles to the direction in which the wave is moving ~Up and Down ~Light is a transverse wave ~ Wavelength consists of a crest and a trough
Longitudinal Waves
~Waves that move the medium parallel to the direction in which the wave is moving ~Back and forth ~Sound is a longitudinal wave ~Wavelength consists of a compression and a rarefaction
Mechanical Waves
~Waves that require a medium to travel ~A medium is any form of matter (solid, liquid, gas) ~The energy moves - not the medium ~Sound is one example of a mechanical wave
Refraction
~When a wave bends due to a change in speed ~When a wave moves from one medium to another at an angle, speed, wavelength, frequency?, and direction changes as it goes into different mediums ~Due to change in speed, the wave bends ~When light waves are traveling through air, they have a certain speed.. When they enter the glass, and then the water, their speed changes
Reflection
~When an object or wave bounces back from a surface; happens when a wave bounces back from a barrier ~All waves can be reflected ~None of the properties of a wave are changed by reflection. The wavelength, frequency, & speed are same before and after reflection. ~The only change is the direction in which the wave is traveling. ~Reflected light waves allow us to see things ~Reflected sound waves allow echoes to occur ~If something is not reflected, it may be absorbed by or transmitted through the item ~EX: Reflections in sound...Echolocation, Sonar, Ultrasonography
Rainbow
~When light enters a particular medium at an angle (or enters a prism) the wave will change it's speed ~Speed depends upon wavelength, and since the colors that make up light have different wavelengths, they have different speeds and will then be visible ~Frequency did not change, that property depends upon the source, not the medium.
Interference
~When two or more waves meet ~Constructive Interference: When two waves meet, combine, and create a wave with a larger amplitude; Crest meets crest ~Destructive Interference: When two waves meet, combine, and create a wave with a smaller amplitude; Crest meets Trough
Vibration
~a disturbance of particles causing back and forth motion ~any movement that follows the same path repeatedly ~Vibration = movement = energy
Pitch
~a measure of how high or ow a sound is perceived to be ~depends on the frequency of the wave ~higher frequency=higher pitch ~less medium=higher pitch
Loudness
~a measure of how well you can hear a sound ~related to amplitude ~higher amplitude(energy) =higher volume ~measure in decibals
Echo
~a reflected sound wave
Electromagnetic Spectrum
~all of the frequencies or wavelengths of electromagnetic radiation ~Radio Waves, Microwaves, Infrared Waves, Visible Light, Ultraviolet Rays, X-Rays, Gamma Rays ~range from longest wavelengths and lowest frequencies to shortest wavelength and highest frequencies ~wave speed is constant across the spectrum bc as wavelength decreases frequency increases (inversely related)
Speed of Light
~in a vacuum: 300,000,000 m/s or 300,000 km/s ~ fastest traveling thing discovered by scientists
Sonar
~man-made technology that uses echoes to locate objects
Ultrasound
~medical device that uses echoes to "see" inside a patient's body without doing surgery ~sends ultrasonic waves that reflect off patient's internal organs and the echoes are then seen on a tv
Luminous
~objects that produce visible light Ex: flames, light bulbs, sun, firefly
Compression
~part of a longitudinal wave where the particles are crowded together
Rarefaction
~part of a longitudinal wave where the particles are spread apart
Ultrasonic
~sounds that are too high for people to hear
Medium
~substance through which a wave can travel ~ can be a solid, liquid, or gas !-Particles of the medium do not travel with the wave!
Oscilloscope
~technological device that can graph representations of sound waves ~changes sound waves/longitudinal waves into transverse waves
Diffraction of Light
~the bending of light waves around a barrier or through an opening ~Diffraction depends on wavelength, because visible light has such a small wavelength it is very difficult for it to bend. (This is the reason buildings can block light) ~Ex- the edges of your shadow appear blurry because of diffraction.
Crest
~the highest point of a transverse wave
Scattering of Light
~the interaction of light with matter that causes light to change direction ~The scattering of light is another reason why light gets dimmer the further it travels from its source. ~Scattering also causes the sky to look blue!
Trough
~the lowest point of a transverse wave
Radiation
~the transfer of energy as electromagnetic waves
Absorption of Light
~the transfer of energy carried by light waves to particles of matter ~This is why a light gets dimmer as it gets further away it gets from the light source
Illumunious
~visible object that is not a light source Ex: any object that you can see... apple
Reflection of Light
~when light waves bounce off barriers they hit, this is the reason we can see objects Regular Reflection: incident rays reflect rays equally Diffuse Reflection: incident rays reflected in a scattered manner can see material but no reflection
Absorption
~when wave is taken in by the matter that it comes in contact with ~Matter takes energy of wave