20.1 Observations: Pulses and

• The wave motion is disturbed by a vibration.

• Our everyday experience shows that when an object vibrates, it also disturbs the Cylinder.

• Push down on the cylin and let it go.
• Waves are sent across the tub by the vibrating cylinder.

• The source of the pulse is your hand pull.
• The rope is the medium in which the pulse travels.
• The rope itself is marked with a ribbon.
• The pulse goes up and down.

• Time is needed for the pulse to travel to the other end of the rope.

• The ball is the source of the pulse and the foam on the surface is the water in the swimming pool.
• The ball should be pushed up the pool.

• The foam pieces bob up as the foam pieces on the water surface and down, but do not travel across.
• It takes a while to get to the pool.

• The pulse should reach the far sides of the pool.

• In the two experiments, we saw that a vibrating source created a moving commotion.

• The material moved at an observable speed.

• The particles of the medium did not travel.

• This by a single beach ball vibration and hump falls back toward its equilibrium level and overshoots, pushing water wave fronts produced by repetitive slightly farther away upward into a hump.
• The beach ball is vibrated by this disturbance.

• The top view interactions of the neighboring sections result in a coordinated down and up.

• When you shake the end of a rope, it will move.
• In this case, the rope is the medium and the source is you.
• Wave motion is caused by a vibrating object.

• The wave front has the same displacement at the same time.

• There are many wave fronts that have a circular shape moving outward on the sur face of the water.

• The top view creates wave fronts.

• Another example of wave mo tion is the stretchy toy called a Slinky.
• If we push or pull the end coil of a stretched Slinky several times, it will pull the coil attached to it.
• That coil pulls the next coil, which in turn pulls the next coil.
• There is a stretching pattern moving along the Slinky toy.

• In a different way, we can disturb a Slinky.

• The water lay ers move in an elliptical path which makes the wave more complicated.

• The propagation and vibration directions are different for a wave.

• The A pulse moving toward the fixed end of a rope is an important property of waves.

• If we want to study simple wave motion and not worry about reflected waves, we need a long medium.

• We've considered mechanical waves in ropes, Slinkies, and water.
• A tuning fork is a simple source of sound waves.

• The pulse is reflected off the fixed end.

• If you touch the prongs, they will vibrate.
• The sound stops when you touch them.
• Waves on the surface of the water are caused by air pressure changes caused by a vibrating tuning fork.

• We call this wave sound.
• A tuning fork disturbs the sound of a longitudinal wave because of the vibrating prongs of nal compressions and decompressions.
• Waves are caused by sound in water.

• If a tuning fork vibrates in a vacuum, there will be no way for the fork to vibrate against each other.
• Sound cannot come out of a vacuum.
• Sound waves will be studied later in the chapter.

• A wave is produced on a rope using physical quantities to find relationships between physical objects.

• The wave travels along the rope at a specific speed.
• There are four quantities that describe the wave started by this vibrating source.
• The motion of a vibrating object is described in the first three.
• The fourth quantity is new.

• The source's mechanical energy is not converted to the medium's internal energy.
• The amplitude of the vibration is the same at all points.

• The vibrating source has a number attached to it.
• According to Eq.

• This expression can be replaced for wavelength.

• There are two repetitive processes in a wave.
• At any clock reading, points a and b have the same phase.

• If we write something.

• The displacements of 2 people are the same.

• The wave equation is compared with the given equa tion.

• 0.10 m is the cosc 2pa bd's value.

• A Slinky vibrates with a 15 cm 10.70 s2 value.

• The speed of a wave and the speed of a vibrating object can be compared and contrasted.

• The speed of a wave is the distance that a disturbance travels in the medium during a time interval divided by that time interval.
• The definition of speed does not explain why a wave has a certain speed.
• In this section, we want to find out what determines the wave speed.

• Two people are holding a toy.
• A pulse on the Slinky starts if the speed of a pulse is the same as the left.
• They vary the pulse is and pull it at a time.

• The speed of the pulse does not depend on the amplitude of the pulse or on its Frequency, as we found in Table 20.2.

• The wave speed is increased by pulling harder on the end of the Slinky.
• As we stretch the Slinky, the coil spread farther apart, with its mass per unit length.
• The speed of a pulse or wave on the Slinky seems to be affected by the force pul ing on the Slinky and its linear density.

• The wave speed is proportional to the square root of the force pulling on the end of the spring if we do similar experiments with stiff springs that stretch less than a Slinky.
• This applies to strings as well.

• The pulling force that one part of the me dium exerts on a neighboring part is indicated by the subscripts M and M. The result makes sense because the more you pull on the spring, the more strongly adjacent parts interact with each other.

• Experiments show that speed is affected by the mass per unit length of vibrating particles.

• This symbol is used in other contexts to indicate the coefficient of friction.
• The depen dence on mass makes sense.
• The time needed to move the next part depends on the mass of the medium.

• The units are correct.
• We take a rope of mass and length, attach one end to a wal, and pul the other end with a spring scale, to exert a known force.
• We will send a pulse after plucking the rope.
• The above expression is used to predict the time interval for a pulse to travel from one end to the other.

• Testing the expression for wave speed.

• We measure end and back again and conduct the experiment from one end of the rope to the other.

• We will get 20 N within this interval.

• 215.0 m2>113 m>s2 is 0.77 s.

• We think the trips will take 7.7 s.

• The outcome is in line with the prediction.
• The speed of a wave depends on the medium.

• The first expression is an operational definition of speed, while the second is a cause-effect relationship.

• The speed of waves in a medium in which no mechanical energy is converted into internal energy depends on the properties of the medium.
• The wavelength of the wave depends on the frequencies of the source and the speed of the wave through the medium.
• If the wave speed is high, the crest of the wave will travel further away from the source.

• The wave speed can be determined by the type of wave.
• The waves travel more slowly in the same me dium.
• The difference is due to the types of medium that occur when the waves are propagating.
• The longitudinal waves require compressions and decompressions, while the layers of the medium slide across each other.

• The wave must travel at the speed of 128 m/s.

• The peg at the end of the violin exerts on the string because it exerts on adjacent parts.

• Waves that travel in a one-dimensional me dium have been investigated.
• If there is no damping of the waves as they prop agates, the amplitude of the vibration at any point in the one-dimensional medium is the same as that of the source.

• Wave crests can be seen on the surface of water.

• A beach bal bobs up and down in the water, creating waves that travel across the water surface in all directions.
• The peaks of the waves are represented by shaded circles.

• As the waves move far from the source, the amplitude of the crests decreases.

• If the wave source uses 10 J of energy every second to produce a pulse, then all of that energy is transferred to the pulse in one pulse per second.

• The total energy of the vibrating particles in the pulse cannot be greater than 10 J.
• Since there are more vibrating particles, the energy per particle will have to decrease.

• Let's do a quantitative analysis.

• The distance from the source decreases the energy per unit circumference length.

• The second ring is half the size of the first ring.
• The Snapshot of wave crests at one instant in time ence length is related to the distance from the source.

• The investi have different sizes.

• You jump off a high board into a pool.

• The water wave is a two-dimensional wave.

• If there is no con version of mechanical energy into internal energy, then the changing amplitude is due to in- reasonable.

• There is no form of distance from the source.

• The Slinky is a one and they are the same.

• Consider a medium that is three-dimensional.
• A fire alarm goes off.

• 10 J>s is the energy output of the source.

• The area of the second sphere is four times larger than the first.

• The energy per unit time per unit area is proportional to the distance from the source.
• The conclusion is consistent with our experience, that we know that the farther we are from the alarm, the quieter the sound becomes.

• The power is spread over the area.

• The intensity of a wave is determined by the energy per unit area per unit time interval that crosses the medium through which it travels.

• Watt per square meter is the unit of intensity since J/s is a watt.

• The energy of a vibrating system depends on the amount of vibration.

• If the energy on the left side of the above decreases by one-fourth when the distance from the point decreases, the wave will travel from the thin rope to the source.

• Until now, we've considered waves moving through a medium with the same properties everywhere.

• Imagine holding a thin rope that is attached to a thicker rope on the right.
• Snapshots of the reflection inverted pulse (oriented like the pulse reflected off the fixed end) returns to your and transmission of a pulse at an interface hand and a partial y transmitted upright pulse travels in the thicker rope.

• The thicker rope is harder to accelerate upward than a thin rope in the first experiment.
• The thick rope has a pulse in it.

• The inverted pulse reflected back toward the left in the thin rope.

• The rope restrains itself.

• Understanding the patterns that occur when waves travel from one medium to another allows us to better transmit information and protect ourselves from unwanted signals.
• Less energy was transmitted forward from the thicker medium in the first experiment.
• The energy from sound waves travels through the air.
• The structure of the ear makes it possible for some of the energy to reach the inner ear.

• The pattern of waves in different media allows geologists to see under the surface.
• Radio waves from the bottom of the ice sheet are indicative of an ice-rock interface.
• The ice sheet rests on rocks.
• There is a sharp, distinctive boundary between the Earth's mantle and its outer core that is determined by the pattern of motion of seismic waves.

• The medium moves with respect to each other when a wave travels through it.
• The elastic property is re lated to the interactions between particles in the medium.
• The density of the medium is characterized by the inertial property.

• A wave traveling in one medium is partially reflected and partially transmitted at the boundary between the media if they have different elastic and insturment properties.
• Waves move from one medium to the other as if there is no change if the elastic and insturment properties of the two media are the same.
• Most of the wave energy is reflected back into the first medium and does not travel into the second medium if the impedances of the two media are very different.

• It's difficult to transmit the sound from the air to the tissue in the side of the body.
• The air has an impedance similar to that of tissue.
• The air-body interface is where most of the ultrasound energy is reflected.
• To overcome this problem, the area of the body to be scanned is covered with a gel that matches the impedance between the emitter and the body surface.
• The gel covered area is held against the emitter.
• The matching allows the wave to travel into the body instead of being reflected off the body's surface.

• One part of a seismometer has the same impedance as the Earth and vibrates during an earthquake.

• The devices are so sensitive that a man can jump on the ground 1 km from the seismometer.

• Many animals are capable of detecting signals.
• Elephants have dense fat in their feet, which matches the impedance of Earth's surface.
• Elephants tend to lean forward on their front feet in order to detect the sound of the ground around them.
• Reports describe Asian 748 Chapter 20 Mechanical Waves elephants trumpeting at the ap proach of an earthquake before humans feel it.

• Waves are not reflected at the boundary between the two media.

• Some of a wave's energy can be absorbed at the boundary between two media or in any part of a medium through which the wave travels.
• Random kinetic energy is turned into thermal energy by the coordinated tions of the atoms in the medium.
• The rate of conversion can be very high or very low.
• A pil ow over your ears absorbs sound.
• Two pillows absorb more.

• A me dium me dium me dium me dium me dium me dium me dium me dium me dium me dium me dium me dium me dium me dium me dium me dium me dium me dium me dium A violin's sound is a combination of almost 20 waves, each of different frequencies and amplitude.

• Adding two pulse through a medium.

• One meet is pulled up by the pulse traveling left from the right side and down by the pulse rope.

• There are three upright pulse that travel from one part of the rope to the other.

• The upright pulse add.

• The sum of the two is what the result is.

• Let's see if this is a good position for waves.

• They send waves.

• The waves will cause the vibrations at these points to be twice as loud.

• The sum of the individual waves is called the sum.

• The A wave pushes point D up while the B wave pushes it down.

• The net displacement is very low.
• If one wave has to travel a distance of one-half, three-halves, or five-halves, then this situation will happen.

• The two waves at D are out of phase.

• The two waves almost cancel each other, so there will be little vibration.

• Let's do a test.
• Take two speakers at different places and predict where our ears will hear the least amount of sound.

• Two sound speakers separated by 100 m face each other and vibrate in unison.
• Determine three places on the line where you can't hear anything.

• Take a picture of the situation.
• All known quantities should be labeled.

• When the waves arrive you should make sure they are equal.

• The waves are represented by the displacement-versus-position graph.

• If ematical relationships between physical quantities are present, you should not hear a sound.

• There are places where we don't hear sound and you have to figure out the equation in the last step.

• The first place is 51 m from the left speaker and 49 m from the right.
• The next place is 53 m - 47 m. The answers seem reasonable.

• We hear almost no sound when we conduct the experiment.

• At positions 50 m, 52 m, 54 m, this condition is satisfied.

• With greater confidence, we can assert the superposition principle.

• Waves move outward when a beach ball bobs up and down in the water.

• The superposition principle can be used to explain the formation of the waves.

• A new wave front can be determined if one adds the disturbances due to all wavelets.

• The pins in the water will be vibrated by shaking the card a straight board.

• A straight wave front is what we predict.

• The cardboard and water wavelet shake the board.

• The path of the plane waves will have a circular opening.

• The results of the testing experiments match the predictions.
• These experiments give us more confidence in the principle.

• It is not possible for two waves to arrive at the same point at the same time, according to your friend.

• Low can sense sound.

• Equal-amplitude 20.7 Sound 753 sound waves of different frequencies will not have the same perceived loudness to humans.
• A wave at 2000hertz will seem louder than a wave at 15000hertz.

• Sound waves are moving.
• The normal atmospheric pres is 1.0.
• The threshold for a young person's ear is less than a billionth of atmospheric pressure.
• The inner ear and the auditory nerves are damaged by sound that is more than this threshold.
• The intensity of the sound is measured by the energy per unit area per unit time interval, rather than the sound's pressure.

• A construction site has an intensity of sound of 0.10 W>m2.

• This looks like a small number to us.
• The total energy is not related to the power per unit area.

• The sound energy is half the size.

• The time interval needs to be vert into seconds and the area into m2.

• The decibel is a unit associated with intensity level.
• A 10-fold increase in intensity is equivalent to an increase of 10 dB.
• The radian is a reminder of one way of quantifying angles, similar to the unit that serves as a reminder of what we are quantifying.

• The sound in an average classroom is 50 decibels.

• A 60-dB sound has 10 times the intensity of a 50-dB sound, which has 10 times the intensity of a 40-dB sound, and so on.

• A subjective impression is what pitch is.
• It doesn't have any units.

• There is more to sound than what is heard.

• Let's use a microphone and a computer to look at a pressure-versus time graph of a sound wave produced by playing one note on a piano.

• The wave is not sinusoidal.
• One or two tuning forks are to blame.

• To answer this question, we need to use two tuning forks with the second fork vibrating twice as much as the first fork.

• The waves must be from the tuning forks.
• Wave 2 is produced by sound.

• The component frequencies are broken down into a complex waveform.

• The height of the line is determined by the wave's amplitude.
• Waves produced by both than those of wave 1.

• A lot of the sounds we hear are complex waves.

• We don't associate a pitch with noise.

• Two tuning forks produce a spectrum of frequencies.

• The violin's com Wave 1 plex wave has a richer tone than the less complex piano sound.

• Only one wave source is playing at a time.

• Waves cause tive pressure caused by the Frequency.
• There is no sound at the time.
• The sound is loud because both waves have a maximum negative pressure varia tion.

• The two wave pressure variations cancel each other, causing a zero pressure disturbance and no sound.

• The two wave frequencies have the same amplification, but it's just 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 800-211-2519 If the beat Frequency is less than a few Frequency, this is easy to hear.

• In precise frequencies, beats are useful.
• If a piano string and a number of tuning forks are sounded at the same time, the piano's middle C string can be set to 262 hertz.
• The piano string needs to be vibrating at either 259 or 265 revolutions per second from the sound source.

• To get the wave, we add the above two waves.

• Understanding how musical instru ments produce sound is based on the position of waves.
• Let's look at stringed instruments first.

• You hold one end in your hand.

• The first wave was produced.

• A pulse moves to the right.

• Each time a pulse returns, you must shake the rope upward.
• The rope has a lot of noise traveling along it.

• Waves are on a string.

• Between the dashed lines, the rope vibrates.

• One half of the wavelength of the wave that has this fundamental Frequency is equal to the length of the rope.

• We think that the fundamental force on its end should be 60.0-N.

• The agreement is very good.
• We have confidence in the expression.

• The second wave of the standing wave on the rope is twice the fundamental vibration.
• The new pulse adds to the pulse that was started earlier.

• We can see a pattern.

• A new pulse after completing a trip up the string.
• Waves moving in opposite directions cause standing waves.

• The phase of the wave is different at different locations.

• The shape of the rope is represented by each line.

• The points vibrate in phase when they reach their maximum displacement.
• When you play a musical instrument, you cause waves.
• When you bow a violin string, you simultaneously wave a wave.

An expression of

• The wave on the string is independent of where the finger is.

• The A string of a violin has a fundamental frequency.
• We can't solve the A string immediately.

• This idea can be used to create an expression for the speed of number multiples of the fundamental: 880, 1320, and so forth.

• A motor attached to the other end of the string exerts a constant horizontal force.

• When the motor is turned on, it vibrates the end of the string at frequencies that increase slowly from zero to a high.

• Blow across the top of the bottle after partially filling it with water.

• The amount of water in the bot tle affects the pitch of the sound.
• The same phenomenon underlies how sound is made in musical instruments made of pipes or tubes.

• The open-open pipe has a pressure pulse at the end.

• When a pressure pulse reaches a closed end, this phase change doesn't happen.

• As air rushes in, the pulse becomes a high-pressure pulse.
• The reflected pulse can be interfered with by a new high-pres sure pulse at this time.

• The open-open pipe has 5 standing wave vibration in it.

• The time interval needed for a pulse to travel down the pipe and back again depends on the standing wave vibrations in the pipes.

• The pipe can vibrate with large amplitude if excited by air pressure pulse at whole number of fundamental frequencies.

• A high-pressure pulse can be felt near the closed end of the pipe.
• A low-pressure pulse returns to the closed end of the pipe after reflection.
• Before a high-pressure pulse returns to the reed, the pulse has to make another trip in the pipe.

• The fundamental Frequency of an open closed pipe clarinet is half that of an open open pipe flute.
• The open-closed pipe's standing wave frequencies are not the same as the fundamental's, but instead are odd whole number multiples, which can cause waves in the open-closed pipe that interfere destructively.

• We can use our understanding of standing waves in pipes to explain how wind instruments produce sounds.
• The reeds are the main sources of sound in clari nets and saxophones.
• The sources of sound in trumpets, trombones, and French horns are the vibrating lips and mouth.
• The pressure pulse that comes from the reeds and mouth pieces is not pure tones, but rather a different type of pulse.
• The input frequencies of the instruments are only reinforced by the pipes attached to the reeds.

• One or more valves or keys can be used to change the resonance of an instrument.
• The open end of the pipe is served by a hole that is opened by the valve.
• The length of the air column in the pipe is changed.
• The sound from the instrument is made up of multiple frequencies because there is usually more than one frequency excited at a time.

• One's voice would have a lower pitch.
• During the experiment, the chamber does not change.
• This experiment is three times higher because of the danger of inhaling this gas.
• This exercise is only theoretical.

• The wavelength of a wave depends on the frequencies of the waves and the speed of the waves in the medium.

• When you hear the horn of a passing car, its pitch is noticeably higher than normal as it approaches and is noticeably lower as it moves away.
• The Dop pler effect occurs when a source of sound and an observer move with respect to each other and the medium in which the sound travels.

• A spectrum analyzer is a device that measures the frequencies of sound.
• Put each in a cart that can move away from the other.
• The air in which the sound travels is at rest with Earth.

• The signal can move towards or away from each other.

• The observed and emitted frequencies are the same.

• The patterns were observed in Table 20.9.

• The waves created by a water beetle bobbing up and down on the water can be used to explain the Doppler effect.
• The crests are moving at a constant speed.

• The distance between adjacent crests is the same as the distance between observer A and observer B.
• Both ob server's frequencies of waves are the same.

• The beetle moves to the right at a slower pace than the wave.
• Each new wave is produced from a point further to the right.

• The beetle hops to the right.

• A and B detect the same things.

• The separation of crests in front of the beetle is used to derive an equation.
• The wave source is the beetle's speed.

• The source Frequency is 1>T.

• The wave travels between hops in line with the patterns found in Table 20.9.

• If the observer moves with respect to the medium and the source is stationary, the observed and source frequencies are different.
• If she had remained stationary, the fronts would have encountered O and the observer more fre quently.
• The fronts are less frequent with O and she.

• We arrive at a general equation for the effect.

• You can use the signs that you have chosen.

• The speed of blood flow is measured using the Doppler effect.

• The waves are reflected by red blood cells.
• The speed of the blood flow and the speed of the blood cell are indicated by S.

• The result shows us how to measure the speed of blood.

• We use it.

• A friend with a ball attached to a string stands on the find an expression for the ratio of the Frequency when the floor swings it in a horizontal circle.
• The ball has a buzzer that is moving towards you.
• When the ball moves away from you.
• The ratio can be rear on one side.
• When ranged to get an expression for the speed of the source, the ball moves away on the other side of the circle.
• The speed of the ball can be determined.

• Draw a picture of the situation.

• The source's speed is S.

• The bal was moving in the correct direction.

• The sound in the air moves in a constant and is equal to 340 m/s.
• There is no shift in the direction of the air.

• An ambulance sirens blares continuously as it approaches you.

• The points in a traveling wave have different phases.

• The new wave front has a superposition of all wavelets because of the previous wave front.

• There are two smal spheres on the surface of a 1.

• What physics ideas were needed to make it work.

How do you know the wavelength of a wave is calcu?

• An explanation for the difference in the wave's speeds is needed.

• The wave has a period of 4.1 m.

• There are conditions needed to create a wave in a storm.

• A wave of a differ 6 is needed.

• Only everyday items can be used.

• If you want to graph the pattern of a wave in dry air at the same pressure and temperature.

• The choices explain why sound travels.

• Two speakers hang from a field.
• The density of water is greater than the density of air.

• Two sound waves are sent down a long distance.

How can you show that an object can produce sound?

• There are 20 mechanical waves.

• A child is on a merry-go-round.

• A boat is moving up and down in the ocean.
• The problem is not a specific answer.

• A large goose lands in a lake and bobs up and down.
• The first wave was created by difficult.

• Assume that the speed of sound in air is 340 m/s for all of these tion of pressure at different positions and times.

• The graph shows the motion of your end.

• People can hear sounds from the points on the rope in different frequencies.
• Determine the wavelength of the clock readings.

What assumptions do you have? If these assumptions are not correct, how fast your tudinal or transverse pulse can go on a Slinky?

• What assumptions do you make when determining the 12?
• A dolphin has a system that emits sound.
• Every decision will be affected by certainties.

• Imagine standing in a pool with a dolphin in the water.

• You push the ball up and down.

thunder came from the same location

• Clarify any assumptions you make in your calculations.

20 m>s 15

• The pulse on rope 1 is very fast.

• A telephone lineman is told to stretch the ment-versus-position graph for a piece of wire between two poles so the poles exert an 800-N force on the Slinky.

• The speed on the G string is 128 m/s.

• Determine the ratio of mass per unit length of the strings.

• You can use whatever you need for your experiments.

• A 20 m long rope is woven to a 16 m long rope.
• The ropes are taut and pulse started in 20.
• The intensity one is reflected at their interface is shown using a sketch and mathematics.
• Draw a picture of a two-dimensional wave that is proportional to the pens just after the pulse reaches the interface between the ropes.

• There are three examples that explain 32.

• The data from the pre vious problem can be used to estimate the energy coming to Earth.
• The case where the Sun pulse each second should be repeated.
• The Earth is about 6400 km in diameter.

• You should state your assumptions.

• You can compare the intensity of a 100W lightbulb while they are traveling through the same medium.

• We can hear the sound of airplanes.

• Understand waves to explain echoes.

• A bat gets a sound wave from another at a speed of 10 m/s.

Would you expect the wave at times of 0.10 s, 0.20 s, 0 1 2 3 4 5 6 7 8 reflected wave pulse to be out of phase with the incident and 0.30 s?

• The vibrating in a swimming pool can be determined.

• The mechanical waves were 38.
• A banjo D string has fun jects that vibrate in the pool.
• The pool damental Frequency is Resolved.

• There are two vibrating objects in a pool.

• They are 6.0 m away from each other.
• How far from the end of the banjo string is the wave speed.
• The vibrating in the previous problem must be a fret.

• A violin string has a mass of 0.89 g.

• The peg exerts force on it.

• A person secures a rope of mass 0.40 kilograms.
• An experiment to convince a friend that ends and puls on the rope exerts a 120-N force.
• The rope sounds like a wave.

• The speed of sound in an ideal gas is determined by the relationship ment.

• The rope is pul ed by two poles, each of which exerts a large amount of force on it.
• The mass per unit length is 0.10.
• What g is a characteristic of the gas.
• The average molar mass for dry air is 28.97 g/ mol, and the line must be vibrated in order to get it.

• Why is the gas nu- 55?
• Estimate the fundamental frequencies of the merator and the mass of the gas in the denominator.

How did you arrive at your answer?

• The speed 56 is calculated using the information from problem 41.
• The sound in the air is the same as the wires on the piano.

By how much is the answer Frequency and the assumptions that you made

• It's hard to hear the sounds of the pool when it's 58.

• One of the thermal energy for heating his building is collected by the owner and converted to the tunnel.
• That is the world's longest underwater vehicular tunnels.

• A wooden flute is open at both ends.

• If you want to run a 40-W light sound that is four-thirds of the amount of energy collected, you need to place a finger hole far from one end.
• You need to justify how you arrive at your answer.

• The lowest wave was 47.
• A very soft sound called "pianississimo" can be heard in music.

• The intensities should be converted to intensitylev on a pipe of the same length but of the other type.

• Two sounds are the same.
• What is the difference between 62 and 62?

• The pitcher throws a vibrating bal.

• The resonant is 105 decibels.

• The water waves show that a plane wave hit the barrier travel of the tube.
• To determine the speed of the wave front, use this informa ing at an angle relative to a line that is parallel to the barrier tion.

• When a plane wave traveling in one me when filled with air hits a border with another, you can use a wave front representation of the dium hitting the border with your vocal tract.
• When the vocal tract wave changes its direction of propagation, the idea of the kinetic theory is used to estimate the vibrating frequencies.

• Take a picture.

• The waves are reflected by red blood cells as they move toward the source.

• The receiver next yells at her to catch a bal.
• Estimate how long it will take to get to the source.
• The sound in the blood is 1500 m/s.

• De travel as a nerve impulse to the brain, be processed, and then travel at a speed of 20 m/s and a stationary observer hears a signal for muscle action back to an arm.

• If the car is not moving, what is heard by an ob about 120 m/s in humans.
• You have to make reasonable server approaching the car at 20 m/s and by observer assumptions about quantities not stated in the problem.

• You record a thunderclap while camping.
• A car drives at a speed of 25 m/s along a road.
• After a flash of paral el, the clap reaches 3.0 s. The train is traveling at 15 m/s.
• Estimate the total power generated by the horn.
• Say what assumptions you made.

• There is a sound of sound that enters away from each other and a sound of sound in the blood.

• If you say "hello" near a vertical 69.
• An echo "hello" comes back after a short delay after a bat emits short sounds at a canyon wall.
• If it was recognizable of .
• As the bat swoops toward a flat wall turns in 2.0 s and sound travels through air at 340 m/s, then at speed 30 m/s, this sound is reflected from the wal back to total distance.
• Bats travel and find food at night.

• A hungry student working in a cafeteria next to a bat.
• The size of the prey belt is indicated by the reflected wave as the plates of food pass on a conveyor.
• The plates are separated by 3.0 m and the belt moves a large animal.
• He moves with the belt at a speed of 6.0 m/min.
• The bat has sound sensors in its ears that can be used to determine the location of the prey.

• A bat-like echolocation system on your car emits a 20,000-hertz sound that returns to the car in 0.18 seconds after being reflected by another car.

• The fluid inside the cochlea of the 81 is affected by the increased pressure against the window.
• You can compare your answers to Problems 78 and 80.
• If you want to hear something.
• The object's distance from you is more accurately measured by nerve cells along the basilar membrane.
• Nerves farthest from the window for the sound to get from you to the object and back to you must consider the distance you travel during the time delay high-frequency sounds.

• The 30% ear can distinguish sounds that are different in frequencies, even though the basilar is only 3 cm long.

• While your car is stationary, you emit a 20,000-hertz signal and get a 22,000-hertz signal back from a re-enactment.

• The human ear can detect sound waves that are stationary.

It is moving towards you, where should you be?

• There is a mechanism that allows the ear to distinguish between sounds.

• The pressure varia causes the eardrum to vibrate.
• The three smal bones in the 87 transmit b and c tional energy.

• The threshold for a barely audible sound is known as the oval window.
• The pressure increase is possible for two.
• The answer is close to reasons.

• The difference in areas increases the pressure by a factor of 15 to 30.

• A magician places broken glass in a beaker full of oil after breaking it with a hammer.
• You should be able to explain what happened.

• You draw a wave front in this chapter.

• The model of light we develop in this chapter is just one example of how the remaining chapters involve using and improving the model of light.

• Humans were thought to emit invisible rays from their eyes.
• The rays were wrapped around the objects to collect information.
• The rays came back to the person's eyes.
• Humans should be able to see in darkness if the model is correct.
• A simple experiment disproves the model.
• If you sit for a while in a room with no light sources, you will not see anything.
• There must be something else to explain how we see things.

• If you want to see the light travel to the wall, shine a laser pointer in a dark room.

• The light bounces back to the wall.
• Put your sees light in the bright spot.

• You can see the path because light reflects off the laser pointer on the wall.

• You can see the path of light reflected from the laser to the wall.

• Dust can be seen illuminated by light.

• To see something, we need a source of light and an ob ject off which the light bounces, and then reaches the eyes of the observer.

• Light travels in a straight-line path between the source of the light and the object reflecting it, then in another straight line between that object and our eyes.

• The first question is illuminated by a lightbulb.

• A laser pointer is useful for studying light propagation.
• Most light sources do not emit light as a single beam.
• The bulb sends light in different directions.
• The wal s, floor, and ceiling are affected by these ideas.
• There are two possible models of how extended sources emit light.

• The rays are sent in different directions.

• The experiments are done in a dark room.

• We predict a dark shadow behind the lightbulb and a pencil behind the rays that don't reach the wall.

• There is a dark shadow on the wall.

• In experiment 1, we predict a light shadow with a fuzzy shaded lightbulb and place a pencil on the wall.

• We predict a shadow illuminated screen with a hint of a shadow.

• The fuzzy, light shadow is not as dark as in experiment 1.

• The wall will be dark.

• The bulb is facing the wal.

• The wall will have a bulb on it.

• The wall is dark.
• The result remains the same if we cover the first hole and poke a hole in a different place.

• Both models predicted the outcome of the experiment.

• Light sources, light propagation, and shadows are sent by each point.

• Each point of the laser light and the sun send one ray.

• The points send rays.

• Parallel rays are the only rays that reach Earth.

• There are multiple rays diverging from that point.

• The hole traveled in different directions.
• Light from a point-like light source must be represented using multiple rays, with the exception of laser light, which can be represented using one ray.

• There was a new phenomenon revealed in the experiments.

• There is no light behind the object.
• There was no dark shadow on the wal in the second experiment.
• A semi-shadow is a region with some light but not all of it.
• It is a fuzzy shadow.

• The sun can be represented as a collection of parallel rays.
• We can represent the laser's narrow beam of light with one ray.

• On a sunny day, a streetlight pole casts a shadow on the ground.
• When held vertically, the meter stick casts a 0.70 m shadow.
• This can be used to determine the height of the pole.

• We sketch the situation first.
• The sun is represented as paral el rays hitting Earth's surface.
• The stick has a shadow of 0.70 m.

• The magnitude is reasonable and the unit is correct.

• The shadow was cast by the stick.
• The pole height is still 13.7 m, but the gles are equal.

• If you hold a candle flame from a blank wall, you don't see the flame on the wal.
• The wall is illumi nated by light coming from the points on the candle flame since each point emits light in all directions.

• We can use a piece of cardboard with a small hole in it to make a projection of the flame on a wal in a dark room.
• Conceptual Ex ercise 21.2 explains how this projection is formed.

• From the bottom ing experiment, ray 1 can see.

• We predict that a piece of stiff paper with a smal hole in it will show an upside-down projection of the flame on the wal because of candle.

• The candle flame is upside down on the wall when you perform the ex periment.

• We have a sketch of the situation.
• The ray diagram can be used to predict the light source.
• If you move the candle closer to the hole, the light from the candle will reach the wall.

• The light from the candle flame can be seen in all directions.
• They should be represented away from the wall.

• Most of the rays are bigger than the others.

• A lightproof box with a side world on a wall is what this camera is.
• A small hole in one wall and a photographic plate or film inside the box ings are projected upside down.

• Pinhole cameras were used to make photographs before the invention of modern cameras.
• You would shine intense light on the person for a long time to photograph them.
• The light reflected off the person would travel through the hole and form a projection of the person on the film.

• A light source in front of a screen with a smal hole in it will be projected upside down on a wal behind the screen.

• Light reflects along straight lines in this section.
• A mirror is used with the represent to reflect a single ray.
• The reflected laser light light emitted from a source and traveling beam is shown.

• The ror is the angle between the incident beam AO and the normal line CO.
• The table shows that the tion came out of the page.

• The top view is always equal to the other.

• They form atractor with the mirror surface.

• This result can be used to predict the outcome of the experiment.

• The table shows the relative directions of light beams from a mirror.

• Two mirrors stand on a table with their faces facing the same direction.

• 1i mirror 2 passes over the target.

• The first figure shows the situation.
• Laser orientations and posi tions will work.
• The beam will pass over the target if we work backward.
• Start by drawing the beam backwards from the target to mirror 2, then to mirror 1 and finally to an appropriate position for the laser pointer.

• The figure is below.
• The process in steps is represented by mirror 1 and then mirror 2 by the incident ray.
• The target is shown in the figure below because the ray that hits mirror 2 is equal to 2u.
• The sum of the angles in a triangle equals 180 degrees and the orientation of the normal line in the figure and the normal lines to the mirrors makes a 90 degree angle with each equal angle of incidence and reflection.
• The reflection on the other side of the mirror is shown above.
• The angle between the incident and the reflected ray incident and reflected angles relative to mirror 1's nor- is 21u mal line are the same.
• We know how to direct the laser.

• The law of reflection can now be applied to a relationship.

• Everyone in the room can see the bright oriented at different angles when we shine a laser beam on a wal.
• The law of reflection states that the light beam should reflect at a par- incident light.

• A light beam shining on a smooth mirror can be represented by a single light ray.

• The reflected laser light is not a single ray.
• The light from the laser hits the parts of the surface that are oriented in different ways, and the light is reflected in many directions.
• The wall was parallel to the incident.
• If we had a clean mirror instead of the wall, the dust rays wouldn't stay parallel after reflection.

• The parallel rays differed after reflection.

• cal ed can see the reflected light when it is reflected by a "bumpy" surface.

• Different parts of a light beam strike different parts of the surface at different angles with respect to the incident light.

• The reflected rays go in different directions on the smooth surface.

• The path of the laser beam in the ex periments is explained in Table 21.1.

• Many people can see the path of light.

• Sunlight coming through the church windows reflects off the dust in the air.

• In the next example, we use both diffuse and specular reflection.

• When light reaches the transparent sur, most of it passes into the room and off, the uncovered windows look almost black but then reflects diffusely many times inside so that little the outside walls do not.

• If the windows are black, they are on the next page.
• If you aren't in the one correct lo, you won't see much sunlight to your eyes.
• You see very little light to explain why, our goal is to see that reflected light.

• When the light shines on the rough, it reflects back at the sun in the window, which is why the walls of the house are bright.

• The reflection from the window does not reach the eye.

• The hole in the eye is similar to a win dow.
• The pupil looks dark when the incident light enters.

• The red eye effect is common at night or with low background lighting.
• Light reflects from the red blood vessels in the back of the eye when the iris is open.
• The reflected light makes thepupil appear red.

• The sun reflects off the water's surface at the shore.
• You can also see sea plants under the surface.
• To see them, light must have entered the water, reflected off the rocks and plants, and then traveled from the surface to your eyes.
• It is not easy to touch a rock under the surface of a pond or lake with a stick.
• You missed the stick.

• The baby's eyes in the photo show red circles in the dust.
• The dome of a church has light from the flash.

• Light rays are drawn from the red spots by shining a laser beam through the air.

• We don't draw rays from the spots to our eyes for simplicity.

• Light can leave through the bottom of the container.
• There are red spots on the ceiling and floor of the 2 1 room and on the bottom of the container.

• The path of the ray changes as it moves through the water.

• When light shines at the air-water boundary at the top surface, the incident light beam is reflected back at the same angle as the angle of incidence.

• Similar things happen to the light beam.
• There are differences.
• When ray 3 reaches the bottom water-air interface it is possible for it to partially reflect at the same angle as the angle of incidence, and for it to partially pass from the water into the air below the container.

• When the incident light is represented by rays 1 and 3, it reflects back along the same line (rays 2 and 4) and passes into the second medium without Chapter 21 reflection.
• The light bends and travels in a different direction if it is not in a straight line.

• We could do an experiment similar to the one we did when studying the incident to measure mal line.

• We could record the angles of the Normal line of incidence and refraction at the air-water and air-glass interface.

• The pattern for al materials is different.

• In 1621 the Dutch scientist Wil ebrord Snel found a pattern.

• The number 1 to 2 is dependent on the two materials the light is traveling through.

• Table 21.6 shows the ratio of the sines of the incident and refraction angles.

• The glass used in Tables 21.5 and 21.6 will bend toward the normal, 1.53 if we define the index of air as 1.00.
• The glass is more dense than water, and it reflects the light more toward the but light going from a higher to normal line.

• As the blood's glu- is narrow, the Refractive index of blood increases.

• Snel's law for this situa water is the blood.
• The air of blood can help determine the concentration of blood sugar.

• A small sample of blood is held by theDividing both sides of Snel's law.

• The light leaves the blood and passes through the air to a row, which is higher than the normal index of refraction of tiny light detectors at the top.

• The index of the blood is higher with pure blood.

• The situation of the patient's blood is 1.37 instead of 1.43 as we sketch.

• The incident angle is 40.0.
• The angle is 61.7.

• 2 air is equal to 1.00.

• The difficulty in touching an object under water with a stick was discussed at the beginning of the section.
• Refraction can help us understand why.
• You can see the example.

• The air is shown below.
• You can see the coin because sunlight enters your eye.

• 2 air is equal to 1.00.

• The light rays in the water make a 42.1 incident angle relative to the normal line at the water-air interface.

• The location of the coin is shown.

• Suppose you light a coin with a laser light and send it to your eye.

• Determine the angle of the light in the water.

• When drawing diagrams, remember: a.
• Most objects do not emit light.
• We draw them as light-emitting objects because they are just sources of reflected light.

• We draw the ones that are most convenient for describing the situation.

• Light reaching our eyes is what makes us see objects.
• Think of the rays that will reach the eyes of the observer.

• Imagine placing a piece of glass in the water.
• If the light reflects off the glass and reaches your eye, you will see it.
• Light hitting the angle when traveling in water.

• A good example is vegetable oil.

• Part is reflected.

• The magic trick described in the opening story is explained here.

• In order for us to see things, they have to either reflect or emit light.

• The reflecting object is different from the material around it.

• Light traveled from water to air in two examples in the last section.

• This behavior can be used to transmit light by optical fibers.

• You perform a series of experiments in which an incident ray under water hits a water-air interface at an increasingly larger angle relative to the normal No refracted light.

• The angle in the air between the reacted ray and the normal line gets bigger as the incident angle gets bigger.

• The light is reflected back into the water at incident angles larger than the critical angle.

• Remember that sin is 90.

• If the incident angle is greater than uc, there is no solution to Snell's law, as sin u2 would be greater than 1.00.
• The light is reflected back into the water.
• There isn't a refracted ray.

• Light travels from a me dium to a medium with a lowerRefractive index.

• The Refractive index is a fundamental physical property of a substance and can be used to identify an unknown substance, confirm its purity, or measure its concentration.
• Medical and industrial applications exist for refractometers.
• In addition to detecting drug tampering in racehorses, veterinarians use portable refrac tometers to measure the total cholesterol in blood and urine.

• As you move the light source apparatus, we have a sketch of the cal block.

• The light ray 1 is what we assume.
• The source of Ray 3 is always oriented in the same way as the curved 90deg in the blood.
• The incident angle is the surface on the bottom and the point cal angle.
• The glass-blood interface has a greater incident angle than Ray 4.
• The critical angle is reflected back into the blood layer.
• We drew a diagram for four lower blocks.

• When the incident angle is larger than the critical angle, the detectors on the top surface stop detecting light.

• We can use it.

• The angle is equal to 0.850 and it is partially reflected.
• When the blood was drawn from the incident.
• The detectors on the top hemi blood bend back toward the normal line when the light reaches this angle.
• As long as the incident into the hemispherical glass block above is small, the detectors on the top of reflected at the second interface are not shown.
• Light will be detected by the net.
• The critical angle is parallel to ray 1 in the top block and thus the apparatus is zero--ray 1 in the lower lows.
• The first glass-blood inter- concentration has a greater incident angle than the index of refraction of the blood.

• You don't see light at angles of and partial y reflected for a different sample of blood.

• ray diagrams can be used to help solve light problems.
• You can use the diagrams to evaluate the final answer.
• If you want to understand how to interpret the mathematical description of light phenomena, be sure to use a ruler.

• An observer at a lower elevation than she wants to see.

• The first mirror reflects downward.
• If you want to see around the second mirror, you have to travel through the tube ner of the Pentagon.
• If the mirror is outside.

• One mirror is pointing down.
• The side of the building with the lower mirror will do.

• A leaf has blown onto the lake.

• The situation is sketched below.

• All the known and unknown quantities are indicated.

• We want to know what size leaf is needed so that any light reflected from the fish and reaching the water surface does not leave the water.
• The leaf is hit by a light incident at a smaler angle.

• The fish is a shining point particle and the leaf is circular.

• Light rays from the object reach the observer.

• Use the sketch and diagram to help.

• We find that sin uc is 1.00 and it is unknown.
• The angle with the greatest sin is quantities.

• Evaluate the results to see if they are true.

• The fish is not safe.

• The equation could be used to solve the word problem.
• The problem-solving procedure is changed.

• A physical process is described in the equation.
• The equation would provide a thick glass bottom of an aquarium and hit an inter solution if a narrow beam of light moved up through the vent.

• The aquarium is surrounded by air.
• The amount of the glass and water is unknown.

• Determine the angle of the light in the water.

• The equation appears to be based on a law.

• 2 sin 90 is the incident angle.

• There is an incident on a different medium.
• The light is not straight.
• The critical angle is 48.

• In this section we look at several applications of reflection, including fiber optics, mirages, and the color of the sky.

• In telecommunications, fibers are used to transmit high-speed data and in medicine to see inside the human body during surgery.
• Understanding the physics behind fiber optics will be helped by the example.

• Imagine that you have a long glass block with a glass-air interface.

• If the incident angle of light in the glass is greater than the critical angle, the light is reflected at the glass-air in terface.
• It hits the bottom of the block at the same angle when it reaches the opposite side.

• The situation is sketched.

• Light travels from glass into the air.
• The critical angle is greater than the incident angle for total internal total internal reflection.
• The light is reflection and total.

• The tom surfaces of the block are parallel to the top and bot.

• The light is hitting the top of the glass.
• The light leaves the block, the light travels the length of the block, or both.

• If the light hits the top light, it will reflect back into the block.

• For 45 incidence, total internal reflection occurs.

• The intensity of light within the block can be reduced by some light coming out of the top and bottom of the incidence.

• During surgery, fiber optics are used.
• A small bundle of glass fibers was used to look inside the body.

• There is a tiny tool that can be inserted along with the fibers.
• The amount of trauma to the joint and surrounding tissue can be reduced with only a smal incision.

• The beam illuminated a piece of furniture.
• The band was wider than the original beam, with violet light on the bottom and red on top.
• The colored band disappeared from the wall after he put an identical prism after the first one.

• Reflecting on things.

• There are several reasons why mirrors are better for reflection.

• 90 relative to the object, 90 relative to the mirror, and 180 relative to the prism, produce an image oriented at 180 relative internal reflection.

• The reflective ability of spires is retained.

• An object viewed through binoculars will appear inverted due to a 90 inversion.

• The forma object the image is one of the consequences of the light's refraction.

• Hot air can be seen just above the pavement on a hot day.

• The hot air has a lower index of refraction than the cooler air above it.
• The path of light when it passes through air with a gradu ally changing is gradual.

• We will only consider one ray from point A in the sky.
• We will assume for simplicity that it passes through several layers of different Refractive index when the light slants downward.
• Its path changes according to the law.
• On a dry day, we see wet layers of lower Refractive index bend away from the normal line and angle pavement.

• At some point, the incident angle becomes so large that the ray starts going up.
• After passing through several layers it enters the eye of the observer, who can see the rays as they travel along a straight line.

• The observer would see more rays coming from a section of the sky in the vicinity of B.
• The location looks blue and shimmers because of the air above the road surface.
• The result looks like water on the road, though it is actually light from the sky.

• The source of light is not the pavement, but the sky.

• Ray bends at the boundary of two layers of air.

• Light coming from point B is what the observer sees.

• Light from the sky creates a blue region that is perceived as water.

• Light reaching Earth from the Sun is a beam of parallel rays.
• Sunlight has all the visible colors.

• The sky is blue.
• The path of light from the Sun to Earth is blue and reflects sunlight in all directions.
• In the first experiment of this chapter, light chalk dust reflecting laser light.
• The other colors are not scattered as much.

• The sky is mostly blue because the atmosphere reflects it.
• Blue light is more efficient than other colors due to their size.

• All colors pass through the atmosphere without changing the direction of the light.
• The blue light reflects in different directions.

• This explanation is supported by probes sent to other planets, where the atmospheres have different chemical and physical compositions than ours.
• The skies of Venus and Mars are not the same as on Earth.

• If our atmosphere reflected 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 888-739-5110 The colors of the clouds reflect the water droplets.

• A ray model of light describes how it behaves.

• Light particles are affected by Earth's gravity and move like projectiles, but since they move very quickly, they aren't noticeable.

• Imagine a shadow light source such as a bulb sending small particles of light from one point to another.
• If we imagine that the bullets bounce off the surface, we can explain the reflection of light.

• The law of reflection is consistent with this.

• Scientists prefer explanations that are easy to understand.
• There is a model of light that does not require interaction.

• Christiaan Huygens was constructing a wave model of light at the same time as the particle model of light was being developed.
• Observations that light reflects tion using the particle model could be the explanation of light refrac tion for the model.

• The wave propagation ideas of Huygens involved the creation of a circular wavelet by each point on a wave front.

• Light bends from the six dots on the wave front.

• There are places where the wavelets add together to form bigger waves.
• The wave front will move a short distance up the page.

• The wave front is reflected by the line of the ray.

• Waves travel at different speeds depending on the medium.

• A new wave front is produced by wavelets.

• There are points on the old wave front.

• The wavelets that come from the left side have smaller radii than those that come from the right side.
• There are new wave crests at places where wavelets add together to form a bigger wave than there is caused by a single wave let.
• The wave's approximate path is shown by a ray that is perpendicular to the new wave front.
• The wave moves more slowly in the region where it bends.
• When the wave travels in a medium with different wave speeds, it changes direction.

• We can use the wave model of light to draw wave fronts for this wave.

• The old wave front is horizontal and the new wave front is not, as the wave travels at different speeds on the right and left side of the figure.

• Wave speed is increasing.

• The front wave speed is slower.

• The principle that was left from the right edge of the wave front explains why the wave changes directions between medium 1 and medium 2.
• The wavelet left from the lower left.

• The propagation direction of the wave becomes closer to normal.

• The light bends away from the normal.
• Light travels more slowly in water than it does in air if the wave model is correct.

• The wave model of light suggests that the speed of light should be lower in water than in the air.

• Measure the speed of light in water to answer the question.
• This experiment is difficult.

• There are different predictions about its speed in water.

• Due to the difficulty in measuring the speed of light in different media, 1 existed in physics for a long time.
• The wave travels farther on the right side in the ments of the speed of light than it does on the left side because of overwhelming experimental support for less dense medium 1.

• The wave model is discussed in more detail in the later chap ter.

• We haven't answered Medium 1.
• We don't know why different media bend light is different.
• We don't know if light propagation is faster or slower in wa ter and other media.
• We don't know how objects light up.
• We don't know which model of light is better--the particle model or the wave model.

• The questions will be investigated in the coming chapters.

• Medium 2 is less dense than medium 1, which causes the wave to bend out.

• Light from these sources illuminates other objects.
• The light reflected off of the object reaches our eyes.

• The incident light is reflected in many different directions if it is on an irregular surface.

As it moves between the media

• A light beam travels through the air and through a thin along the laser beam.
• It leaves paral el to the original di blocking the light.

• One ray is sent by each point of a light-emitting object.
• There is a base with a right triangular prism on it.
• Two rays are sent by a narrow light beam.

• The model mentioned in Question 2 can only be tested on one side of the prism and the other side of the back side.

• A physical law with air submerged in the water is represented by a narrow light beam from a laser that travels through water and is vented by physicists to represent the direction of travel.

• There are 11 semi-shadows of objects on Earth.

• You are at the side of the road.

• The bottom of the river 13 can be seen by standing beside it.

What do you need to do to create different shadows on the river?

• Your head looks fuzzy when you see a beam of light.

• You can only see a semi-shadow of an object if you include drawings.

• When you move away from a light, it does your shadow.
• Sometimes a highway looks wet on a hot sunny day.

• If you are 32, you can't see a pencil on the wall.

• The Moon and the Sun have diameters that are close to 33.

If the Moon were in the same line, what should you see?

• You have to make a drawing or graph as part of your solution if you draw a sketch showing the wal.

• A total solar eclipse can only be seen by people in a very narrow region on Earth.
• You are standing under a tree.
• There is a can to see stars.
• During a total solar eclipse, the shadow of the tree is 34 m long and is twice the size of the Sun, the Moon, and Earth.

• The summer ecology research job involves 2.
• An experimental site has a shadow from a surgeon's hand documenting the growth of trees.
• One obstructs her view.
• Suggestions for a day you don't use your tree-height-measuring instrument.
• There is an alternative light source that avoids this difficulty.
• Provide some sketches for your plan.

• There is a lunar eclipse when the Moon is 8.
• The shadow of Earth was left by you.
• You can deter your house at 7 a.m. and then drive to the site in 2.0 hours.
• How to get the shape of Earth.
• Can you build a sundial so that you can leave the site at a certain time?

• To describe his reasoning, draw a picture.

• The shadows of your hands on the wall look fuzzy.
• There is a small mirror.
• You can see the shadow of a glass while holding the mirror.
• There is a light spot on the wall that is the same height as the mirror.

• To answer the question, draw a ray diagram.
• The candle is an extended light source.

• You wonder if there is water in the well.
• What direction does the light go?
• To answer the question, draw a ray diagram.

• The mirror should show the interface between the media, the normal line, the middle and the reflected and refracted rays.

• A beam of light will travel in the opposite direction after it reflects cyclohexane at an angle of 48 degrees.
• Even if you change the direction of the mirror, the angle off it is the same.
• The index of refraction is what the pointer is pointing at.

• Two mirrors are facing the same direction.
• An aquarium open at the top has struck the horizontal mirror at an angle of 65 degrees.
• You hit the mirror by shining a laser pointer into the top of it.
• The angle of incidence at the vertical mirror and the direction angle relative to the vertical should be determined so that it is incident on the air-water interface.
• You can see a bright spot after leaving the mirror.
• A sketch beam hits the bottom of the aquarium.

• The inverted bird in beam goes straight through and makes a spot on the wall when you shine the Sun on the back.

If you fill the container with where the observer is, what will happen to this spot?

• A few apartment buildings draw a ray diagram for each situation if you indicate any assumptions used.

• Careful drawing three different light beams leaves the bulb that reflects from the bowl mirror to move away.

• A light beam hits the interface between air and an unknown material at an angle of 43 degrees.

• The water has an angle of 42.0 degrees.
• Determine the angle of the incident ray.

• The eye's lens is behind the vitreous 18.
• A flat mirror has an axis in the plane of humor that occupies most of the eyebal.

• A narrow beam of light traveling in the lens problems comes to the interface with the humor at a 23 degree angle.

• You have a block of glass with a sketch of the experiment and a diagram of the experiment that is shaped with air inside.
• Figure P21.37b shows the path of a light.

• There is a crab in the aquarium.
• Indicate any assumptions you made.

• The light leaves the top surface of the cube.

• You swim under water at night and shine a laser pointer so that it hits the water-air interface at an incident angle of 52 degrees.

• There is a light on the boundary between the two media.

• There is a light on the boundary between the two media.
• Determine the angle of 34.
• What is the critical angle of tourmaline if the light makes an angle of 47?

• There is an acorn on the bot tom of the pool.

• A swimming pool is long and deep.

• Refer to the stone's mass density and Refractive index.

• The short side is oriented in a certain direction.
• The slanted side of the prism has a horizontal ray hitting it.

• The experiment was formed by Euclid.
• A coin was placed at the bot tom of a mug.

• He added water to the equation because he wanted to do a process without changing his eyes.

• The experiment and 43 should be repeated.
• You can explain how the process works.

• You have a candle and a piece of paper.
• The candle flame cut in it is slightly larger than the lar hole.
• The paper between the candle and the wal is described by an equation.
• The 1.00 sin 53 is shown in the draw diagrams.

• The in dle is halfway between the candle and wal and the wal is near the wal.

• The two devices used to measure the Refractive index of an unknown media are known.

• A light beam in the liquid is turned into a material.
• There is a liquid made by the incident ray.
• The incident beam is adjusted for total inter 58.0 angle with the normal as it enters the glass and a 36.4 nal reflection, and the equation for the angle of total internal angle with the normal in the gelatin.

• The Sun is 25 feet above the horizon.
• You place a point-like source of light at the bottom of a raft and want to orient a mirror so that sunlight reflects off the tainer filled with vegetable oil.
• Do you need to place a 0.30 cm tive index 1.33 if the mirror travels at an angle of 45 in the water of refrac height from the light source?

• There is a small pond with a light pole on it.

• You can see the water at the top of the pole in Figure P21.36.
• A ray diagram can be used to calculate the Refractive index.
• Determine the minimum value of the help to find a point on the surface of the water from where the Refractive index for the prism is.
• Determine the expression for ternal y.

• Imagine that you are in Rome and admiring the famous pipe.
• You think about getting a face out of the pipe.

• Your height is 1.6 m above the water level and the fountain's depth is 0.40 m.

• A piece of glass has a light ray on it.
• Determine how far the ray travels in the glass.
• The angle will interface at the calculated angle.

• There is a mirror at the bottom of the pool.
• An observer on the ground laser beam enters the water at 30 relative to the normal, hits sees only one color of light from each rain the mirror reflects, and comes back out of the water.

• The drops that send red and violet are far away from the water entry point.

• A diagram of a ray.

• Behind the observer is a scuba diver at the bottom of a lake.

• There is violet from this drop.

• The index of refraction of a medium is different for 61. rainbows are only seen when you are between the Sun different colors

• After reflecting off the back surface of the drop, the light needs to move back and forth between the front and back surfaces as it leaves the front surface.

• The colors of light are separated by drops.
• You need to observe the light coming from the Sun.

• She could see violet light coming from a 62.
• The red light from the drop in the sky that entered one side is not reflected by the water droplets in the other side.
• She sees red light when the light reflects off the back surface and then goes back out line of view to see the beam of sunlight on the same side as it entered.
• When the angle is 40 degrees, what is the closest angle to the light?

• There is a rainbow in 63.
• Raindrops reflect different colors of light.

• The color violet is more colored than red.

• Only the violet light is the problem.

• The Refractive index of water for violet light is greater than that for red light.

• The greenhouse effect is caused by the emission rate of radiation from nomenon.
• Most of Earth would have a climate similar to that of the Sun without the greenhouse.

• Earth's cross section would be greatly reduced if the Sun continued to irradiate our upper atmosphere.

• To be absorbed by the surface area of Earth that is exposed to the Sun.

• Earth's average surface has to equal its absorption energy rate from the Sun.

• The mean surface temperature is much warmer than the greenhouse gases in the atmosphere.
• The gases absorb the radiation.
• The increased temperature of Earth's surface reflects some of it back to Earth.
• Due to the greenhouse effect, Earth emits less energy into space than it would without it.
• Why hasn't gases been used?

• The carbon dioxide concentration in the atmo is correct.