OBJ 5OBJ 5

Series CircuitsSeries Circuits

Series circuits are the type of circuits Series circuits are the type of circuits that most Christams tree lights have. that most Christams tree lights have. If one bulb goes out, all the bulbs go If one bulb goes out, all the bulbs go out.out.

Parallel CircuitsParallel Circuits

Parallel circuits are the type of Parallel circuits are the type of circuits that are used in houses. If circuits that are used in houses. If one bulb goes out…..(your tv goes one bulb goes out…..(your tv goes out), all the other things……out), all the other things……refrigerator, lights, and radio can still refrigerator, lights, and radio can still work.work.

Open circuitOpen circuit

An open circuits is when the An open circuits is when the electricity can not flow (since it electricity can not flow (since it needs to go all the way around in a needs to go all the way around in a circle to flow)circle to flow)

Open circuits = nothing works (light Open circuits = nothing works (light bulb is off)bulb is off)

Closed circuitsClosed circuits Closed circuits is circuits where the Closed circuits is circuits where the

electricity is flowing……..no gap……electricity is flowing……..no gap……electricity can go all the way around electricity can go all the way around in a circle.in a circle.

Closed circuits = Everything works Closed circuits = Everything works (light bulb is on)(light bulb is on)

RepelRepel

Repel means to pull away.Repel means to pull away.

Charges that repel from each Charges that repel from each other…..pull away from each other.other…..pull away from each other.

(Like charges) Looks the (Like charges) Looks the same…….repel (pull away from each same…….repel (pull away from each other)other)

AttractAttract

Attract means to be pulled Attract means to be pulled together…….charges that attract together…….charges that attract other charges are pulled together…other charges are pulled together…

Opposites attractOpposites attract

ConductorsConductors

Conductors let electricity flow …..Conductors let electricity flow …..(can hurt you)…..the metal that (can hurt you)…..the metal that electricity flows through.electricity flows through.

Be careful not to get shocked.Be careful not to get shocked.

InsulatorsInsulators

Insulators do not allow electricity to Insulators do not allow electricity to flow……..(helps protect you)…..the flow……..(helps protect you)…..the plastic around a cord.plastic around a cord.

ReflectionReflection

ReflectionReflection is the is the change in direction change in direction of a of a wavewave front at front at an an interfaceinterface between two between two different different mediamedia so so that the wave front that the wave front returns into the returns into the medium from medium from which it originatedwhich it originated

RefractionRefraction

RefractionRefraction is the is the change in change in direction of a direction of a wavewave due to a due to a change in its change in its speedspeed like when like when a wave passes a wave passes from one medium from one medium to another.to another.

InterferenceInterference

InterferenceInterference is the addition is the addition ((superpositionsuperposition) ) of two or more of two or more waveswaves that that result in a new result in a new wave pattern.wave pattern.

Constructive InterferenceConstructive Interference

Constructive Constructive interference is interference is when the when the troughs and troughs and peaks of 2 peaks of 2 waves line up waves line up to make a to make a bigger wave.bigger wave.

Destructive InterferenceDestructive Interference Destructive Destructive

interference is interference is when the trough when the trough of one wave lines of one wave lines up with the crest up with the crest of another wave. of another wave.

Generally there Generally there is no or little is no or little sound when this sound when this happens. happens.

Wave ApplicationsWave Applications Microwaves are used for cooking and Microwaves are used for cooking and

heating food.heating food. Infrared waves are used in heat lamps.Infrared waves are used in heat lamps. Ultraviolet waves cause sunburn/skin Ultraviolet waves cause sunburn/skin

cancercancer X-rays are used for medical diagnoses X-rays are used for medical diagnoses Gamma Rays are used in nuclear Gamma Rays are used in nuclear

explosions.explosions.

Electromagnetic SpectrumElectromagnetic Spectrum The The electromagnetic electromagnetic

(EM) spectrum(EM) spectrum is the is the range of all possible range of all possible electromagnetic radiatelectromagnetic radiationion. The electromagnetic . The electromagnetic spectrum of an object spectrum of an object is the characteristic is the characteristic distribution of distribution of electromagnetic electromagnetic radiation from that radiation from that object.object.

Radio WavesRadio Waves Radio waves Radio waves

are located at are located at one end of the one end of the electromagnetielectromagnetic spectrum.c spectrum.

Located near Located near microwaves microwaves and has the and has the longest longest wavelengths.wavelengths.

Law of Conservation of Law of Conservation of EnergyEnergy

The Law of Conservation of The Law of Conservation of Energy states that energy can’t Energy states that energy can’t be created nor destroyed….only be created nor destroyed….only changed from one form to changed from one form to another.another.

NodeNode

A A nodenode is a point along a is a point along a standing wavestanding wave where the wave where the wave has minimal has minimal amplitudeamplitude. This has . This has implications in several fields. For implications in several fields. For instance, in a instance, in a guitarguitar string, the string, the ends of the string are nodes. ends of the string are nodes.

Antinode = opposite of nodeAntinode = opposite of node

HarmonicsHarmonics

The The harmonicharmonic of a of a wavewave is a is a component component frequencyfrequency of the of the signalsignal that is an that is an integerinteger multiple of the multiple of the fundamental frequencyfundamental frequency. For example, . For example, if the frequency is if the frequency is ff, the harmonics , the harmonics have frequency 2have frequency 2ff, 3, 3ff, 4, 4ff, etc, as well , etc, as well as as ff itself itself

Speed of the waveSpeed of the wave

As the frequency of As the frequency of an electromagnetic an electromagnetic wave increases, wave increases, the speed of the the speed of the wave stays the wave stays the same.same.

EnergyEnergy A photon is the A photon is the

particle that carries particle that carries radiant energy.radiant energy.

The amount of The amount of energy a photon energy a photon carries is carries is determined by its determined by its frequency.frequency.

It travels (in a It travels (in a vacuumvacuum) at the ) at the speed of lightspeed of light

Gamma Rays/X-raysGamma Rays/X-rays

The most energetic electromagnetic The most energetic electromagnetic waves are Gamma rays and X-rays.waves are Gamma rays and X-rays.

Ultraviolet LightUltraviolet Light

The frequencies of The frequencies of ultraviolet light are ultraviolet light are slightly higher than slightly higher than visible light.visible light.

Your body needs Your body needs ultraviolet waves ultraviolet waves to make vitamin D. to make vitamin D. (helps build bones)(helps build bones)

MicrowavesMicrowaves

Microwaves are Microwaves are used for cooking.used for cooking.

Television Television satellites use satellites use microwaves to microwaves to transmit.transmit.

Infrared WavesInfrared Waves

Infrared waves Infrared waves produce thermal produce thermal energyenergy

FM vs. AMFM vs. AM

FM frequencies FM frequencies tend to be clearer tend to be clearer than AM than AM frequencies frequencies because the because the strength of the strength of the signal stays the signal stays the same.same.

TV signals are in TV signals are in the FM range.the FM range.

Hearing DamageHearing Damage

A sound A sound intensity above intensity above 120 dB may 120 dB may cause cause permanent permanent hearing damagehearing damage

ReverberationReverberation

Scientists and Scientists and engineers may engineers may recommend recommend carpets and carpets and draperies for the draperies for the walls of a walls of a concert hall to concert hall to reduce excess reduce excess reverberation.reverberation.

RadarRadar

Police use radio waves Police use radio waves in a method called in a method called radar to detect radar to detect speeders.speeders.

RadarRadar is a system that is a system that uses uses electromagneticelectromagnetic waves to identify the waves to identify the range, altitude, range, altitude, direction, or speed of direction, or speed of both moving and fixed.both moving and fixed.

Radio waves travel Radio waves travel at the speed of at the speed of light (186,000 light (186,000 miles per second or miles per second or 300,000,000 300,000,000 meters per second)meters per second)

Newton’s Third Law of Newton’s Third Law of MotionMotion

- To every force or - To every force or action, there is always an action, there is always an equal and opposite equal and opposite reaction.reaction.

If object A exerts a force If object A exerts a force on object B, then object on object B, then object B also exerts an equal B also exerts an equal and opposite force on and opposite force on object A. object A.

The cannon has a The cannon has a backward kick when it is backward kick when it is fired.fired.."."

Newton’s Second Law of Newton’s Second Law of Motion - Motion - ""

F = ma: F = ma: the net force on an the net force on an

object is equal to the object is equal to the mass of the object mass of the object multiplied by its multiplied by its acceleration. acceleration.

You bunt – the ball You bunt – the ball doesn’t go far. You doesn’t go far. You swing hard (more swing hard (more force), the object force), the object accelerates faster.accelerates faster.

FrictionFriction

Friction-Friction- when 2 when 2 objects rub objects rub together. It together. It generates heat. generates heat. Example (rub your Example (rub your hands together) hands together)

MicroweldsMicrowelds

MicroweldsMicrowelds – the – the forces you need to forces you need to overcome to get overcome to get something moving.something moving.

Static frictionStatic friction

Static frictionStatic friction - - Static friction is a Static friction is a force between two force between two objects that are not objects that are not moving relative to moving relative to each other. each other.

Sliding FrictionSliding Friction--

Sliding FrictionSliding Friction- - is when two objects is when two objects are rubbing against are rubbing against each other. Putting each other. Putting a book flat on a a book flat on a desk and moving desk and moving it around is an it around is an example of sliding example of sliding friction.friction.

Rolling FrictionRolling Friction

Rolling frictionRolling friction- is - is the the resistanceresistance that that occurs when a occurs when a round object such round object such as a train rolling on as a train rolling on a track or a ball a track or a ball rolling on a rolling on a surface.surface.

Air resistanceAir resistance

Air resistanceAir resistance – – Like Like turbulence…….objeturbulence…….objects slowing down in cts slowing down in the wind. Running the wind. Running into the wind.into the wind.

Law of GravitationLaw of Gravitation

Law of Law of GravitationGravitation - - states that any two states that any two objects exert a objects exert a gravitational force gravitational force of attraction on of attraction on each other. The each other. The moon’s moon’s gravitational force gravitational force causes tides.causes tides.

Gravitational Acceleration Gravitational Acceleration (gravity constant(gravity constant))

Gravity Constant Gravity Constant

9.8 m/s9.8 m/s22 (If you get (If you get thrown out of a thrown out of a plane, you will plane, you will accelerate to the accelerate to the eart at 9 m/seart at 9 m/s22))

WeightWeight

Weight Weight – Changes – Changes with gravity. It Is with gravity. It Is different on every different on every planet.planet.

MassMass

Mass Mass – Always – Always remains the same. remains the same. Triple Beam Triple Beam balance can balance can measure mass. measure mass.

ProjectilesProjectiles

ProjectilesProjectiles – – Objects that are Objects that are launched and fly launched and fly through the air through the air (bullets, missiles)(bullets, missiles)

Centripetal AccelerationCentripetal Acceleration

– – Acceleration Acceleration toward the center toward the center of a curved or of a curved or circular path.circular path.

Centripetal ForceCentripetal Force--

Centripetal Centripetal ForceForce- force - force directed towards directed towards the center of the the center of the circle for an object circle for an object moving in a moving in a circular motion.circular motion.

Newton’s 1st Law of Newton’s 1st Law of MotionMotion

––Objects in motion Objects in motion will stay in motion will stay in motion and objects at rest and objects at rest will stay at rest…will stay at rest…unless a force acts unless a force acts on them. The ball on them. The ball will stay at rest will stay at rest (not move) unless (not move) unless the dog moves it.the dog moves it.

MomentumMomentum

MomentumMomentum = = (mass)(velocity) (mass)(velocity)

P = (M)(V)P = (M)(V)

(The bus has a lot of (The bus has a lot of

mass so if it moving, mass so if it moving, the momentum will the momentum will be large. If it is not be large. If it is not moving then it has no moving then it has no momentum)momentum)

Law of Conservation of Law of Conservation of MomentumMomentum - -

For a collision For a collision occurring between occurring between object 1 and object 2 object 1 and object 2 in an in an isolated systemisolated system, , the total momentum the total momentum of the two objects of the two objects before the collision is before the collision is equal to the total equal to the total momentum of the momentum of the two objects after the two objects after the collision collision

MV = MVMV = MV

FrequencyFrequency

Higher frequency = high sound Higher frequency = high sound = More waves = shorter = More waves = shorter wavelengthwavelength

Low frequency = Low sound Low frequency = Low sound =Less waves= longer =Less waves= longer wavelengthwavelength

Period of a WavePeriod of a Wave

The The periodperiod is the is the durationduration of of one one cyclecycle in a repeating event. in a repeating event.

FrequencyFrequency is a is a measuremeasure of the of the number of occurrences of a number of occurrences of a repeating event per unit repeating event per unit timetime. .

VibrationsVibrations Sound is caused by vibrationsSound is caused by vibrations

Sound requires a medium (does Sound requires a medium (does not happen in outer space since it not happen in outer space since it is a vacuum.)is a vacuum.)

Sound will travel through water at Sound will travel through water at 20 degrees Celsius slower than 20 degrees Celsius slower than water at 80 degrees Celsius. water at 80 degrees Celsius.

EnergyEnergyThe amount of energy a wave The amount of energy a wave

has determines it’s has determines it’s amplitude.amplitude.

SoundSound

The unit used to measure sound The unit used to measure sound intensity is the decibel.intensity is the decibel.

Pitch is how high or low a sound Pitch is how high or low a sound seems to be.seems to be.

When a person moves toward a When a person moves toward a sound, the compressions of the sound, the compressions of the wave are pushed together.wave are pushed together.

FrequencyFrequency

The frequency at which a The frequency at which a string vibrates is its natural string vibrates is its natural frequencyfrequency

The frequencies of an The frequencies of an instrument’s tone that are instrument’s tone that are multiples of the fundamental multiples of the fundamental frequency are overtones.frequency are overtones.

InstrumentsInstrumentsBrass and wind instruments Brass and wind instruments

make sounds by vibrating a make sounds by vibrating a column of air.column of air.

Beats are produced by 2 Beats are produced by 2 sound with different sound with different frequenciesfrequencies

FMFM

FM broadcastingFM broadcasting is a is a broadcastbroadcast technologytechnology invented by invented by Edwin Howard ArmstrongEdwin Howard Armstrong

FM carrier wave frequencies vary FM carrier wave frequencies vary from 88 Mhz to 108 Mhzfrom 88 Mhz to 108 Mhz

FM = Frequency ModulationFM = Frequency Modulation

RadioRadio

Each radio station broadcasts on Each radio station broadcasts on one frequency called a carrier one frequency called a carrier wave.wave.

Information can be added to a Information can be added to a radio carrier wave by frequency radio carrier wave by frequency modulation and amplitude modulation and amplitude modulation.modulation.

SoundSound

Violins, harps, and guitars Violins, harps, and guitars produce sound by vibrating produce sound by vibrating strings.strings.

A flute player changes the length A flute player changes the length of a column of air by opening of a column of air by opening and closing holes which helps and closing holes which helps make each different sound.make each different sound.

FormulasFormulas

Formula PracticeFormula Practice The frequency is 30. What is the The frequency is 30. What is the

period of the wave.period of the wave.

1/301/30

The period is 10, what is the The period is 10, what is the frequency of the wave?frequency of the wave?

1/101/10

ProblemProblem

If the velocity If the velocity of the wave is of the wave is 76 m/s and the 76 m/s and the frequency is 4. frequency is 4. What is the What is the wavelength?wavelength?

76 = (4)( x)76 = (4)( x)

76 = (4)(x)76 = (4)(x)

44

19 = x19 = x

Problem Problem

If the If the frequency is 4 frequency is 4 Hz and the Hz and the wavelength is wavelength is 11 m. What is 11 m. What is the velocity?the velocity?

x = ( 4)(11)x = ( 4)(11)

x = 44 m/sx = 44 m/s

ProblemProblem

If the velocity If the velocity is 60 m/s and is 60 m/s and the the wavelength is wavelength is 15 m. What is 15 m. What is the frequency?the frequency?

60 = (x)60 = (x)(15)(15)

60 = (x)60 = (x)(15)(15)

1515

4 = x4 = x

Non-RenewableNon-Renewable

Non-renewable Non-renewable means it can not means it can not be replaced in a be replaced in a timely manner.timely manner.

Fossil fuels are Fossil fuels are non-renewable as non-renewable as is nuclear energy.is nuclear energy.

Fossil FuelsFossil Fuels

Fossil fuels include petroleum, oil, Fossil fuels include petroleum, oil, natural gas, and coal.natural gas, and coal.

Fossil fuels are formed from the buried Fossil fuels are formed from the buried remains of dead plants and animals.remains of dead plants and animals.

It can takes millions of years to It can takes millions of years to replace them.replace them.

Petroleum (Oil)Petroleum (Oil)

PetroleumPetroleum is formed is formed from the preserved from the preserved remains of remains of prehistoricprehistoric zooplanktonzooplankton and and algaealgae which have been which have been settled to the sea (or settled to the sea (or lake) bottom in large lake) bottom in large quantities under quantities under anoxic conditionsanoxic conditions

Natural GasNatural Gas Natural gasNatural gas is a is a gaseousgaseous

fossil fuel consisting fossil fuel consisting primarily of methane but primarily of methane but including significant including significant quantities of ethane, quantities of ethane, propane, butane, and propane, butane, and pentane—pentane—

CoalCoal Land plants tend to Land plants tend to

make coal.make coal.

It takes millions of It takes millions of years and a great years and a great deal of pressure to deal of pressure to generally make generally make coal.coal.

Nuclear EnergyNuclear Energy Nuclear energy is made when a Nuclear energy is made when a

nuclear reactor uses the energy from nuclear reactor uses the energy from a controlled nuclear chain reaction a controlled nuclear chain reaction (the rods) control the chain reaction (the rods) control the chain reaction since they absorb neutrons. It takes since they absorb neutrons. It takes a lot of money to make and maintain a lot of money to make and maintain nuclear power plants.nuclear power plants.

Nuclear WasteNuclear Waste

Nuclear Waste is an unwanted Nuclear Waste is an unwanted product of nuclear energy.product of nuclear energy.

Do you want nuclear waste stored in Do you want nuclear waste stored in your neighborhood? Why or why your neighborhood? Why or why not?not?

ChernobylChernobyl There was a nuclear There was a nuclear

meltdown in Russia at meltdown in Russia at Chernobyl.Chernobyl.

PeoplePeople were badly were badly contaminated, resulting in contaminated, resulting in the evacuation and the evacuation and resettlement of over resettlement of over 336,000 people. Soviet 336,000 people. Soviet authorities later forbade authorities later forbade doctors to cite "radiation" doctors to cite "radiation" on death certificates.on death certificates.[2][2]

Oil (Petroleum)Oil (Petroleum)

CoalCoal

Nuclear PowerNuclear Power

Natural GasNatural Gas

HydroelectricityHydroelectricity

GeothermalGeothermal

Wind energyWind energy

Solar Solar

Tidal energyTidal energy

ColorColor

An object’s color An object’s color depends on the depends on the wavelength of wavelength of light it reflects.light it reflects.

Color = what Color = what wavelength of wavelength of light the object light the object reflects.reflects.

You see a red You see a red apple…..because it apple…..because it reflects red light reflects red light back to your back to your eyes……(also eyes……(also absorbs all other absorbs all other colors….)colors….)

You see red since You see red since red is reflected.red is reflected.

BlackBlack

You see black You see black because objects because objects absorb all colors absorb all colors and reflect and reflect either very small either very small amount or amount or nothing.nothing.

WhiteWhite Objects that look Objects that look

white, look like white, look like that since they that since they reflects back all reflects back all the colors..the colors..

White light is White light is made up of all made up of all the three primary the three primary colors of light.colors of light.

White fence = White fence = reflects all the reflects all the colors back.colors back.

FiltersFilters

If your sunglasses If your sunglasses have yellow lenses, have yellow lenses, things look yellow.things look yellow.

When the lenses When the lenses are red, things look are red, things look red.red.

Your sunglass Your sunglass lenses are filters .lenses are filters .

Filters are Filters are transparent materials transparent materials that transmit one or that transmit one or more colors of light more colors of light but absorbs all but absorbs all others.others.

The color of a filter, The color of a filter, is the color of the is the color of the light that it light that it transmits.transmits.

RodsRods Rods are 1 type Rods are 1 type

of nerve cell that of nerve cell that makes up a makes up a retina.retina.

Rods are thinner Rods are thinner than cones.than cones.

Rods are sensitive Rods are sensitive to dim light.to dim light.

Rods are located Rods are located in the peripheral in the peripheral areas of a retina. areas of a retina.

Rods are most Rods are most useful for night useful for night vision.vision.

ConesCones One type of cell One type of cell

in the retina that in the retina that allows you to allows you to distinguish distinguish colors and colors and detailed shapes detailed shapes of objects.of objects.

Cones are very Cones are very important in the important in the daytime.daytime.

Cones are located Cones are located near the center of near the center of the retina.the retina.

Color BlindnessColor Blindness About 8 % of men About 8 % of men

and about a half a and about a half a percent of percent of females, are color females, are color blind.blind.

Usually people Usually people that are color blind that are color blind can not distinguish can not distinguish reds and greens.reds and greens.

It is a inherited It is a inherited sex-linked sex-linked condition in condition in which certain which certain cones do not cones do not function function properly.properly.

PigmentPigment

A pigment is a A pigment is a colored materials colored materials that results from that results from the different the different wavelengths of wavelengths of light that the light that the pigment reflects. pigment reflects.

ColorsColors The 3 primary The 3 primary

colors of light is colors of light is red, green, and red, green, and blue.blue.

When the 3 When the 3 primary colors of primary colors of light are mixed in light are mixed in equal amounts, equal amounts, they produce they produce white.white.

The color of a The color of a pigment results pigment results from the from the different different wavelengths of wavelengths of light that the light that the pigment reflects.pigment reflects.

Paint PigmentsPaint Pigments

Paints are made with Paints are made with pigments.pigments.

Pigments usually are Pigments usually are made from chemical made from chemical compounds such as compounds such as titanium oxide titanium oxide (bright white (bright white pigment), and lead pigment), and lead chromate (bright chromate (bright yellow highway yellow highway paint).paint).

The three primary The three primary pigments are pigments are magenta (bluish magenta (bluish red), cyan (greenish red), cyan (greenish blue), and yellow.blue), and yellow.

A primary pigment’s A primary pigment’s color depends on color depends on the color of light it the color of light it reflects.reflects.

Mixing pigmentsMixing pigments The color of a The color of a

mixture of two mixture of two primary pigments is primary pigments is determined by the determined by the primary colors of primary colors of light that both light that both pigments reflect.pigments reflect.

The three primary The three primary colors of pigment colors of pigment appear to be black appear to be black when they are when they are mixed.mixed.

Because black Because black results from the results from the absence of color, absence of color, the primary the primary pigments are called pigments are called subtractive colors.subtractive colors.

ExtensionExtension Why do our pupils Why do our pupils

appear black?appear black?

Almost all the light that Almost all the light that enters our eyes enters our eyes through the pupils is through the pupils is absorbed by the retina.absorbed by the retina.

What is the difference What is the difference between primary between primary colors of light and colors of light and primary colors of primary colors of pigment?pigment?

Primary colors of light Primary colors of light are red green and are red green and blue.blue.

Primary colors of Primary colors of pigment are magenta. pigment are magenta. Cyan, and yellow. Cyan, and yellow.

Primary colors of light Primary colors of light transmit the color you transmit the color you see, while primary see, while primary colors of pigment, colors of pigment, reflect the color you reflect the color you see.see.

LightLight Objects can Objects can

absorb light, absorb light, reflect light, and reflect light, and allow light to pass allow light to pass through them.through them.

The type of matter The type of matter in an object in an object determines the determines the amount of light it amount of light it absorbs, reflects, absorbs, reflects, and transmits.and transmits.

OpaqueOpaque

Objects that are Objects that are opaque only opaque only absorbs and absorbs and reflects light – reflects light – no light passes no light passes through it.through it.

My walls are My walls are opaque as is this opaque as is this beehive.beehive.

TransparentTransparent Translucent Translucent

materials materials transmit almost transmit almost all of the light all of the light that strikes them.that strikes them.

TranslucentTranslucent

Translucent Translucent objects allow some objects allow some light to pass light to pass through them but through them but you can not see you can not see through them through them perfectly.perfectly.

Curtains and Curtains and frosted glass are frosted glass are translucent.translucent.

Law of ReflectionLaw of Reflection

The Law of The Law of Reflection states Reflection states that whatever that whatever angle the light angle the light wave strikes a wave strikes a surface, the light surface, the light wave will be wave will be reflected at that reflected at that same angle.same angle.

QuestionQuestion Why can you Why can you

see your see your reflection on a reflection on a smooth marble smooth marble floor and not a floor and not a brick building?brick building?

AnswerAnswer Rough surfaces like Rough surfaces like

brick walls…..cause brick walls…..cause diffuse reflection diffuse reflection which is when the which is when the uneven surface uneven surface causes incoming causes incoming parallel light waves parallel light waves to be reflected in to be reflected in many different many different directions.directions.

RefractionRefraction

Refraction is Refraction is caused by a caused by a change in the change in the speed of the speed of the wave when it wave when it passes from one passes from one material material (medium) to (medium) to another.another.

Index of RefractionIndex of Refraction A property of the A property of the

material that material that indicates how much it indicates how much it reduces the speed of reduces the speed of light (how much it light (how much it makes the light makes the light bend).bend).

If Index of Refraction If Index of Refraction is a big number, the is a big number, the more the light is more the light is slowed down…slowed down…

Eyeglasses, Eyeglasses, binoculars, binoculars, cameras, and cameras, and microscopes microscopes use refraction.use refraction.

PrismsPrisms

The triangular The triangular prism refracts the prism refracts the light twice (once light twice (once when it enters when it enters and again when it and again when it leaves the prism.)leaves the prism.)

Because the longer Because the longer wavelengths of wavelengths of light are refracted light are refracted less than the less than the shorter shorter wavelengths, red wavelengths, red light is bent the light is bent the least and the least and the colors seem to colors seem to separate out.separate out.

RainbowsRainbows Rain drops also refract Rain drops also refract

light just like prisms. light just like prisms.

The refraction of the The refraction of the different wavelengths different wavelengths can cause white light can cause white light from the sun to from the sun to separate into different separate into different colors (red, orange, colors (red, orange, yellow, green, blue, yellow, green, blue, indigo, and violet.)indigo, and violet.)

MiragesMirages

A mirage is an A mirage is an image of a image of a distant object distant object produced by the produced by the refraction of refraction of light through air light through air layers of layers of different different densities.densities.

First Class LeverFirst Class Lever

EF is between fulcrum and RF Does not multiply force Resistance moves farther than Effort. Multiplies the distance the effort force travels

Second Class leverSecond Class lever

RF is between fulcrum and EF Effort moves farther than Resistance. Multiplies EF, but does not change its direction

Third Class LeverThird Class Lever

Fulcrum is between EF and RF Effort moves farther than Resistance. Multiplies EF and changes its direction

HINTHINT

Remember the letters FRERemember the letters FRE The The first letter (for 1st class) is "F"  first letter (for 1st class) is "F"  and "F" for Fulcrum in the middleand "F" for Fulcrum in the middle

The second letter (for 2nd class) The second letter (for 2nd class) is "R" and Resistance is in the is "R" and Resistance is in the middlemiddle

The third letter (for 3rd class) is The third letter (for 3rd class) is "E" and Effort is in the middle"E" and Effort is in the middle