CHAPTER 17&18 NOTES

KONICHEK

I. WAVE- A rhythmic disturbance I. WAVE- A rhythmic disturbance through matter or spacethrough matter or space

A. Medium- any matter through A. Medium- any matter through which the wave travels throughwhich the wave travels through

B. Mechanical wave- waves B. Mechanical wave- waves which require a mediumwhich require a medium

II. Light wavesII. Light waves A. Travel through empty spaceA. Travel through empty space B. Travel at 3x10B. Travel at 3x1088m/sm/s c. Called electromagnetic wavesc. Called electromagnetic waves 1. Visible light, others1. Visible light, others 2.Combination of 2 forces, the 2.Combination of 2 forces, the

electrical and magnetic forces vibrating at electrical and magnetic forces vibrating at right angles to each otherright angles to each other

III. WAVES TRANSFER ENERGYIII. WAVES TRANSFER ENERGY A. Waves have the ability to do work.A. Waves have the ability to do work. 1. Sound on eardrum1. Sound on eardrum 2. Tsunami/Tidal waves2. Tsunami/Tidal waves

IV. ENERGY SPREADS OUT AS A WAVE IV. ENERGY SPREADS OUT AS A WAVE TRAVELSTRAVELS

A. As distance increases a sound wave A. As distance increases a sound wave loses some of itloses some of it’’s energys energy

1. Energy spreads out over distance, 1. Energy spreads out over distance,

V. VIBRATIONS AND WAVESV. VIBRATIONS AND WAVES A. Waves are related to vibrations.A. Waves are related to vibrations. 1. Vibrations are created by energy1. Vibrations are created by energy B. Vibrating objects produce wavesB. Vibrating objects produce waves C. Vibrations involve transformation of C. Vibrations involve transformation of

energy.energy. 1. Oscillating spring1. Oscillating spring D. Waves can pass through a series of D. Waves can pass through a series of

vibrating objects.vibrating objects. 1. The Ke of the wave can pass through 1. The Ke of the wave can pass through

Harmonic motionHarmonic motion

VIBRATIONS CAUSE WAVESVIBRATIONS CAUSE WAVES

VI. Transverse and Longitudinal VI. Transverse and Longitudinal waveswaves

A. Transverse wave- A wave which A. Transverse wave- A wave which vibrates at right angles to the direction vibrates at right angles to the direction it movesit moves

1. Water wave, light waves1. Water wave, light waves B. Longitudinal waves- waves which B. Longitudinal waves- waves which

vibrate in the same direction as they vibrate in the same direction as they movemove

1. Sound wave1. Sound wave

TRANSVERSE WAVETRANSVERSE WAVE

SOUND WAVE- LONGITUDINAL WAVE

VII. Surface wave-occurs on the boundary area between different mediums

A. Move both perpendicular and parallel ( water waves)

VIII. CHARACTERISTICS OF WAVES

A. wave properties

1. All transverse waves look about the same

a. Sine curve- S shaped

1. Sine wave- Waves which are made up of Sine curves.

2. Crest- highest point if a wave2. Crest- highest point if a wave

3. Trough- the lowest point of a wave3. Trough- the lowest point of a wave

4. Amplitude- This is the height of a wave 4. Amplitude- This is the height of a wave from a fixed point( normal)from a fixed point( normal)

a. Determines the amount of energy a. Determines the amount of energy in a wave.in a wave.

5. Wavelength- the distance from one 5. Wavelength- the distance from one point on a wave to the same point on the point on a wave to the same point on the next wave next wave

a, Units are cm, angstroms, a, Units are cm, angstroms, nanometersnanometers

AMPLITUDE – THIS IS THE AMPLITUDE – THIS IS THE HEIGHT- DETERMINES ENERGYHEIGHT- DETERMINES ENERGY

WAVELENGTH

WAVELENGTH WAVELENGTH DETERMINATIONDETERMINATION

6. frequency- The number of waves past a point in one second

a. Units Hertz( Hz) b. Wave Speed= wavelength x frequency 1. Depends on the medium a. Sound waves

B Kinetic theory- the structure of the matter will determine the speed

a. solids, liquids, gases-- examples

C. Speed of light is finite 3x108m/s 1. 7 ½ times around the Earth in 1

second

D. Doppler effect- The apparent change in frequency of the wave caused by the motion of the source or the observer

1. Towards the source - wavelength is shorter( blue, higher pitch)

2. Away from the source- wavelength is longer( red or lower pitch)

DOPPLER EFFECTDOPPLER EFFECT

IX. wave interactionsIX. wave interactions A. Reflection- The bouncing of a wave off a barrier.A. Reflection- The bouncing of a wave off a barrier. 1. Incident wave-source to barrier1. Incident wave-source to barrier 2. Reflective wave-barrier to detector2. Reflective wave-barrier to detector 3. Angle of incidence-angle formed from the 3. Angle of incidence-angle formed from the

normal to sourcenormal to source 4. Angle of reflection-angle formed from the normal 4. Angle of reflection-angle formed from the normal

to detectorto detector 5. Law of Reflection- the angle of incidence equals 5. Law of Reflection- the angle of incidence equals

the angle of reflection the angle of reflection

B. Diffraction-The bending of a wave around B. Diffraction-The bending of a wave around a barrier.a barrier.

1. Diffraction gratings- pieces of 1. Diffraction gratings- pieces of glass or plastic with many parallel slitsglass or plastic with many parallel slits

a, Spreads out white light into the a, Spreads out white light into the spectrumspectrum

b used to determine the b used to determine the composition of celestial objectscomposition of celestial objects

REFLECTION

REFLECTION OF SOUND-ECHO

C. Refraction- The bending of light as it C. Refraction- The bending of light as it passes from one medium to anotherpasses from one medium to another

1. Change in the speed of the 1. Change in the speed of the wavewave

REFRACTION OF LIGHTREFRACTION OF LIGHT

REFRACTION IN WATERREFRACTION IN WATER

SEPERATION OF WHITE LIGHTSEPERATION OF WHITE LIGHT

• D. Interference- The result of when waves collide• 1. Constructive- crest meets crest and troughs

meet troughs• a. Waves reinforce each other• 2. Destructive- crest meets trough• a. Cancel each other out. • 3.standing waves-The reflected wave have the

same amplitude, speed and frequency.• a. Don’t move through the medium- cause the

medium to vibrate •

Constructive Interference

DESTRUCTIVE INTEREFRENCEDESTRUCTIVE INTEREFRENCE

X SOUND WAVESX SOUND WAVES A. PRODUCING SOUNDSA. PRODUCING SOUNDS 1. VIBRATION -Needs energy- The back and forth motion of 1. VIBRATION -Needs energy- The back and forth motion of

mattermatter B Sound wave- a longitudinal wave produced by a vibration in a B Sound wave- a longitudinal wave produced by a vibration in a

mediummedium C. SPEED OF SOUND- Depends upon the medium, itC. SPEED OF SOUND- Depends upon the medium, it’’s traveling s traveling

through, and the temperature of the mediumthrough, and the temperature of the medium 1. in air at 20 degrees Celsius 340m/s1. in air at 20 degrees Celsius 340m/s 2. in solids 15 times faster2. in solids 15 times faster 3. in liquids 4 times faster3. in liquids 4 times faster D. The speed of sound changes as the temperature of the medium D. The speed of sound changes as the temperature of the medium

changeschanges 1.speed increases or decreases .6m/s for each degree 1.speed increases or decreases .6m/s for each degree

CelsiusCelsius

XI. INTENSITY AND LOUDNESSXI. INTENSITY AND LOUDNESS A. Loudness is the perception of the rate at A. Loudness is the perception of the rate at which sound energy enters the ear.which sound energy enters the ear. B. Intensity- The actual measurement of the B. Intensity- The actual measurement of the rat-. high intensity waves produce large rat-. high intensity waves produce large amplitude and this produces a loud sound.amplitude and this produces a loud sound. C. Intensity level- measured by comparing C. Intensity level- measured by comparing sounds to the lowest possible sound heard by sounds to the lowest possible sound heard by humanshumans 1. measured in decibels( dB)1. measured in decibels( dB) a. breathing =10 dB, chain saw a. breathing =10 dB, chain saw =115dB =115dB

XII. DANGERS OF SOUND

A. intensity levels over 90dB cause permanent ear damage

B. a single exposure over 150 dB can break the eardrum.

1, ear protection in places which are extremely loud

C. Noise- bothersome, harsh, unappealing sounds.

1. noise pollution- an excess of unwanted sounds

 

XII FREQUENCY AND PITCH A. Pitch- the ears perception of frequency 1. high frequency= high pitch 2, low frequency= low pitch B. Ranges of frequency 1. humans- 20 to 20,000 hz 2. dogs- 15 to 50,000 3. bats 1000 to 120000 C ultrasonics- sounds above the human

range of hearing.

XIV. SOUND WAVE BEHAVIOR A. echoes- the reflected sound wave is an

echo 1. echoes can’t be detected if the

time between the sound and the echo is at least .05 seconds.

B. Sonar- Uses the reflection of sound waves as an information gathering process. SOUND NAVIGATION AND RANGING

C. DIFFRACTION OF SOUND

C. DIFFRACTION OF SOUND 1. sounds bend around corners

rather easily because of their long wavelength D. Refraction of sound waves- Sound

traveling through differnt densities of air. 1. during the day sounds don’t

travel as far because of the warm air refracting the sounds upward,

2. at night the warm air above refracts the sounds downward so the sounds seem like thet travel farther

XIII. HEARING A. regions of the ear- outer, middle and inner 1. outer ear is fleshy and funnels sounds into the eardrum a. eardrum- a tympanic membrane which vibrates

when struck by sounds 2. Middle ear- 3 bones composition a. hammer( malleus) b. anvil( incus) c. stirrup( stapes) 3. Inner ear- Cochlea and semicircular canels a. changes the mechanical sound wave into the

electrical impulse which is sent to the brain.

The ear-whoThe ear-who’’s listening?s listening?

VI. MUSIC

A. Regular patterns of sound

B. Musical inturments- produce sounds by vibrating strings or columns of air, or vibrating membranes

1. rely on standing waves.

 

C, Classification of instruments

1. strings- Use a vibrating string and a resonating cavity

a. pitch depends on the diameter and the length of the string

2. Woodwinds- Use a vibrating reed, and pitch is changed by changing the length of the column of air

 

 

 

 

3.BRASS- The lips vibrate and the pitch is changed by using a slide or keys which change the lengt of the air column

4. drums- they keep a beat

a. Tympany- able to change the pitch by regulating te tightness of the membrane

D. Resonance-The vibrating of the body of the insturment at the same frequency as the nusical notes being played.

VIII. ULTRASOUND AND SONAR

A. SONAR- SOUND NAVIGATION AND RANGING

1. used to determine the depth of waters, and schools of fish

2. distance calculations from time.

a. D=VT, V is the velocity of sound in water, T is the time it takes for the return wave.

IX. ULTRASOUNDS IN MEDICINE

a. In pregnancies to detect any defects

b. Echogram of the heart to see if the muscle is fully functioning

c. Advantages- does subject tissue to x-ray radiation which may cause tissue damage

d. High frequency waves can pass through soft tissue very easily

CHAPTER 18 NOTESCHAPTER 18 NOTES

XIV. NATURE OF LIGHTXIV. NATURE OF LIGHT A. Theories on the composition of lightA. Theories on the composition of light '' 1. Wave model-Light travels in waves1. Wave model-Light travels in waves

a. interference patterns like a wave- Young a. interference patterns like a wave- Young’’s s observationobservation b. transverse wave-electromagnetic in nature b. transverse wave-electromagnetic in nature

c. electric and magnetic waves vibrating at 90 c. electric and magnetic waves vibrating at 90 degrees to each other degrees to each other

d. Einstein's photoelectric effect- won the noble prize d. Einstein's photoelectric effect- won the noble prize for the discovery ( EARLY QUANTUM THEORY) for the discovery ( EARLY QUANTUM THEORY)

1. Problem- why do electrons fly off metal when 1. Problem- why do electrons fly off metal when struck by high energy lightstruck by high energy light

2. Particle theory of light- Light occurs in nature as discreet little bundles of energy

a. photon-a packet of radiant energy. b. No mass c. Energy of the photon is dependant

on the wavelength of light 2. Light is weird- sometimes it acts like a

wave, other times acts like a particle.

B. Energy of light is proportional to the frequency B. Energy of light is proportional to the frequency of the light.of the light.

1. high frequency short wavelength high 1. high frequency short wavelength high energy- Blue light.energy- Blue light.

C. Speed of light depends on the medium-3xlOC. Speed of light depends on the medium-3xlO88 m/s in space.m/s in space.

1. according to most scientists is the speed 1. according to most scientists is the speed limit of the universe- special relativity.limit of the universe- special relativity.

2. E=mc2. E=mc22

D.Light intensity- the quantity which measures D.Light intensity- the quantity which measures the amount of light illuminating a surfacethe amount of light illuminating a surface

1. obeys the inverse square law. I=1/d1. obeys the inverse square law. I=1/d22

XV.ELECTROMAGANETIC SPECTRUM- XV.ELECTROMAGANETIC SPECTRUM- a listing of all the possible kinds of light a listing of all the possible kinds of light energy from short to long wavelength.energy from short to long wavelength. A.Cosmic rays-energy photons produced A.Cosmic rays-energy photons produced by the reactions of high energy nuclear by the reactions of high energy nuclear transformations-such as the creation of the transformations-such as the creation of the universe.universe. 1. studying- the structure and 1. studying- the structure and formation of matter.formation of matter. 2.Big bang- the event which 2.Big bang- the event which supposedly created the universe.supposedly created the universe.

B.Gamma rays- High energy photons 1. produced by the decay of a neutron a.Ne- + e+ + protons + neutrinos 2.Used in cancer therapy. 3. Gamma ray burst- These are stars

near the end of their life which explode in huge burst of gamma rays- if they were close enough would destroy the life on earth

C.X-Ray- Caused by bombarding tungsten C.X-Ray- Caused by bombarding tungsten with fast moving electrons.with fast moving electrons.

1. Used to examine inside the body1. Used to examine inside the body

2. Given off when a black hole sucks in 2. Given off when a black hole sucks in matter from a binary starmatter from a binary star

D. UltravioletD. Ultraviolet 1. responsible for suntan, sunburn, 1. responsible for suntan, sunburn,

skin cancerskin cancer 2. 2. earth is protected by the Ozone earth is protected by the Ozone

layer- filters out UVlayer- filters out UV '' 3. Used in surgery to sterilize the 3. Used in surgery to sterilize the

surgical equipment. surgical equipment.

HERE YA GO SUN BATHERSHERE YA GO SUN BATHERS

Cancerous growth- SUNBATHERS!Cancerous growth- SUNBATHERS!

E. Visible light- Detected by living organisms E. Visible light- Detected by living organisms with their eyesightwith their eyesight

1. Composed of R.O.Y. G. B.I.V. this is 1. Composed of R.O.Y. G. B.I.V. this is from long to short wavelength.from long to short wavelength.

2. Red light is bent the least and blue light 2. Red light is bent the least and blue light is bent the most in a rainbowis bent the most in a rainbow

a. Blue has shorter wavelengths, red a. Blue has shorter wavelengths, red has longerhas longer

Visible spectrum- ROY G BIVVisible spectrum- ROY G BIV

• F. Infra Red- This is the radiation given off by warm objects.

• 1. Pit Vipers detect warm blooded prey

• 2. night time photography

G. Microwave- short wave radio G. Microwave- short wave radio

1 Used in communications1 Used in communications

2.cooking- water must be present- 2.cooking- water must be present- the water molecule resonates at the the water molecule resonates at the same frequency, so it causes objects same frequency, so it causes objects to warm..to warm..

• H. Radio waves- Used in communicationsH. Radio waves- Used in communications• 1. AM- amplitude modulations- The 1. AM- amplitude modulations- The

height of the wave is being changed, height of the wave is being changed, a.news, sports types of programming b. a.news, sports types of programming b. Travels a longer distance- bounces off the Travels a longer distance- bounces off the ionosphere.ionosphere.

• 2. FM- the frequency of the wave 2. FM- the frequency of the wave changes a. Usually musical changes a. Usually musical programming.programming.

U. Television- The combination of an audio and visual signal

1 .High definition TV - combines the technology of computers and TV to get more pixels on the screen, hence the picture is so much better.

• XVI Polarized light- This is light of only one plane.

• A. Polarized filters- This allows light of only 1 plane to pass.

• 1. Reduces glare- That’s why they are good to wear when you’re in a boat or in snow covered areas.