1 Ch. 24 Waves, Sound, Light Section 1 Waves A disturbance that moves through matter or space and carries energyMatter does not move from place to place.Energy transfers through the matter.Think of the wave in a stadium.The people (matter) do not change seats, but the energy travels around the stadium.
2 Transverse waves A mechanical wave (Can only move through matter) Causes particles to move back and forth at right angles to the direction of the wave motion.cresttrough
3 Compression Waves A mechanical wave (through matter only) Causes particles to move back and forth along the same direction in which the wave is moving.
4 Electromagnetic Waves Can travel through empty space.Transverse WavesLight wavesX raysRadio wavesInfrared wavesContain electric and magnetic part.
16 Wave Speed Electromagnetic waves: light waves Travel fastest: Space Air (gas)WaterTransparent solidMechanical Waves: compression/transverseSolidsAirDo not travel through space
17 Section 2 Sound Waves Sound Waves = Compression Waves Cannot travel through empty space.Travel fastest through solids, then liquids, then gases.
18 Sound intensity Amount of energy carried by the wave. Measured by the amplitude.
19 Frequency and Pitch. Pitch The human perception of the frequency of sound.Sounds with a low pitch have a low frequency.Sounds with a high pitch have a high frequency.
20 The Human Ear Outer Ear Visible ear and ear canal. Compression wave funnelCup your hand around your ear?
21 Middle Ear Sound amplifier Eardrum 3 smallest bones in the body Tiny membrane that acts like a drumhead and vibrates with the compression waves.3 smallest bones in the bodyHammer - MalleusAnvil - IncusStirrup - Stapes
22 Inner ear The sound converter The amplified compression waves travel from the stirrup to the cochlea.CochleaFluid filledSnail shell shaped organ lined with billions of tiny hairs.Hairs convert compression waves into nerve impulses.Nerve impulses travel through auditory nerve to brain where they are interpreted as sound.Semi Circular Canals: Acts as device to keep a human balanced.
24 Sound reflection Reverberations Echolocation Echoes Sounds that reflectEcholocationProcess of locating objects by bouncing sounds off of them.Bats, Dolphins, Whales
25 Homework Find the speed at which sound travels in feet/second in air. Describe the path of a sound wave from my voice box to your brain. Begin with the origination of the energy and end with you understanding what I say. One paragraph with correct grammar. Will be collected. 10 pts.
27 Light Waves are….. Electromagnetic waves Can travel through matter or spaceAble to travel up to 185,000 miles/s in empty space.Able to travel from the sun to earth (150 million km) in 8 minutes.Able to travel the fastest in empty space and the slowest in solids. (glass)
34 How we see! Light waves reflect off of an object. Reflected light waves enter eye through cornea.Transparent layer of outer eye.Waves pass through the pupil.Opening in the eye controlled by the iris.Waves then pass through the lens.Flexible disc that changes shape to allow you to focus on near and far objects.Lens focuses waves on retina.Back wall of the eye.
35 Retina Contains over a hundred million light sensitive cells. Rods Sensitive to dim lightHelp us to see in darkness.ConesEnable us to see colors.3 typesRed/yellowGreen/yellowBlue/violet