Муниципальное общеобразовательное учреждение «Гимназия № 1» г. Белгорода
For Physicists
Спецкурс по физике
для учащихся 11 классов
физико–математического профиля
Составитель: Л.П. Черкашина
учитель английского языка
Предисловие
Как общеобразовательный предмет иностранный язык помогает развитию школьника, его профессиональной ориентации.
Большую актуальность приобретает формирование кругозора старших школьников средствами иностранного языка. Это возможно в условиях профильно-ориентированного обучения иностранному языку.
Цель спецкурса – способствовать воспитанию осознанного отношения к выбору профессии, потребности в практическом использовании английского языка в будущей профессиональной деятельности.
Данный спецкурс «Для физиков» рассчитан на учащихся классов физико-математического профиля, который даёт им возможность осваивать английский язык под углом зрения своих профессиональных интересов.
Курс построен на основе знаний, навыков и умений, приобретенных учащимися не только в базовом образовании по иностранному языку, но и по физике.
Данное пособие включает материалы, соответствующие основным разделами курса физики: «Механика», «Молекулярная физика и термодинамика», «Электричество», «Оптика», «Колебания и волны», «Строение атома и атомного ядра», а также приложение. Приложение содержит познавательный материал из области физики.
Изучение физико-математического курса по иностранному языку формирует у школьников потребность в физических знаниях, приучает их к учёту и анализу физических понятий на английском языке.
Таким образом, профильная дифференциация может стать одним из действенных средств повышения эффективности обучения иностранному языку в школе.
Text 1
1. It has long been known that when experiments are to be performed, one cannot rely too much upon the human senses of touch, sight, hearing, etc., to make accurate observations. Methods of measurement that rely upon the senses entirely are called subjective methods. Methods that make use of scientific instruments are generally called subjective methods.
2. In the early history of science, laws were frequently discovered by the use of subjective methods. Progress was slow, however, until such methods were replaced by objective methods using measuring instruments devised to give greater and greater precision.
3. It is true that many scientific discoveries have been made in the past with what we now would call the crudest of apparatus and equipment. It is the development of precision instruments and apparatus, however, that has led, particularly within the last several decades, to discoveries that are far-reaching in their theoretical implications and are of extreme practical importance to the advancement of civilization.
Words to be Learnt
advancement n measurement n
development n method n
discover v perform v
equipment n precision n
experiment n rely v
law n replace v
Answer the Questions
1. What has long been known concerning the human senses? 2.Why is that the human senses of touch, sight and hearing cannot be relied upon? 3. What methods are called subjective? 4. What methods are called objective? 5. What methods were used in the early history of science? 6. Why was the progress of science slow in the early history? 7. What did the objective methods give to science? 8. What has the development of precision instruments led to?
What can you say on the following
1. Methods of measurement that rely upon the senses entirely are called subjective methods. Why?
2. Methods that make use of scientific instruments are generally called objective methods. Why?
Text 2
SOURCES OF POWER
The industrial progress of mankind is based on power: power for industrial plants, machines, heating and lighting systems, transport, and communication. In fact, one can hardly find a sphere where power is not required.
At present most of the power required is obtained mainly from two sources. One is from the burning of fossil fuels, i. e.1 coal, natural gas and oil, for producing heat that will operate internal- and external-combustion engines. Many of these engines will actuate generators, which produce electricity. The second way of producing electricity is by means of generators that get their power from steam or water turbines. Electricity so produced then flows through transmission lines to houses, industrial plats, enterprises, etc.
It should be noted, however, that the generation of electricity by these conventional processes is highly uneconomic. Actually, only about 40 per cent of heat in the fuel is converted into electricity. Besides, the world resources of fossil fuels are not ever-lasting. On the other hand,2 the power produced by able to provide for only a small fraction of the power required in the near future.
Therefore much effort and thought is being given to other means of generating electricity.
One is the energy of hot waters. Not long ago we began utilizing hot underground water for heating and hot water supply, and in some cases, for the generation of electric power.
Another promising field for the production of electricity is the use of ocean tides. Our engineers are engaged in designing tidal power stations of various capacities. The first station utilizing this principle began operating in the Soviet Union on the Barents Sea not long ago.
The energy of the Sun, which is being used in various ways, represents a practically unlimited source.
Using atomic fuel for the production of electricity is highly promising. It is a well-known fact, that one pound of uranium contains as much energy as three million pounds of coal, so cheap power can be provided wherever it is required. However, the efficiency reached in generating power from atomic fuel is not high, namely 40 per cent.
No wonder, therefore, that scientist all over the world are doing their best3 to find mere efficient ways of generating electricity directly from the fuel (without using intermediate cycles). They already succeeded in developing some processes whiсh are much more efficient, as high as 80 per cent, and in creating a number of devices capable of giving a higher efficiency.
Scientists are hard at work4 trying to solve all these and many other problems.
Notes on the Text
i. e. (лат. id est) = that is – то есть
On the other hand – с другой стороны; on the one hand — с одной стороны
to do one’s best – делать всё от себя зависящее
hard at work – упорно работают (трудятся)
Words to be Learnt
actuate v efficiency n namely adv
besides prp engine n per cent n
burn (burnt) v external a promising a
capable a however adv reach v
capacity n i. e. = id est represent v
case n internal a source n
combustion n mainly adv tide n
contain wherever adv conventional a
directly adv
Answer the Questions
1. What is the industrial progress of mankind based on? 2. Which is the first widely applied method of producing electricity at present? 3. Which is the second way of generating power? 4. What (how high) is the efficiency of these two methods? 5. What do we use the energy of hot waters for? 6. When and where did the first power station using ocean tides begin operating in the USSR? 7. What can you promising for the production of electricity? 9. Is the efficiency of generating power from atomic fuel high or not? 11. How high may the efficiency of devices converting electricity directly from the fuel be?
What can you say on the following
1. One of the promising fields for the production of electricity is the use of ocean tides. How?
2. Using atomic fuel for the production of electricity is highly promising. Why?
Text 3
WORK, POWER AND ENERGY
A man does work when he climbs a hill by lifting himself against the pull of gravity; steam engine and move it by pressure against a resistance; the electric current does work by means of a motion when it drives the air compressor in an electric car and forces air into the compression tank. Whenever an agent exerts force on a body and causes the point of application to move in the direction of the force, the agent does mechanical work. Unless the point of application of the force has a component of motion in the direction, in which the force acts, no work in physical sense is done.
The three units of work that are in common use are known to every student. They are the foot-pound used among some English-speaking countries, the kilogram-meter used in the metric system and the erg used in the c.g.s. system.1
The units of power are horse power, the watt and the kilowatt. One horse power equals 746 watts, or 0.746 kilowatts. The power capacity of dynamo electric generators and electric motors is now universally expressed in kilowatts.
The energy a body possesses represents its capacity to do work. It is, therefore, measured in the same units as work. The energy a body has due to motion is known as kinetic energy. A weight which has been lifted from the floor to the top of the table has had work on it; if we allow the weight to fall back again to the floor, it will get velocity and, therefore, kinetic energy. This energy was simply “stored up” in the weight when it was at rest on the table, it had energy due to its position on the table; and we call this energy potential. In other words, potential energy is the energy of a mass due to its position.
The well-known law is that any matter possesses energy. Hot steam is able to do work; and we may say heat is a form of energy. The burning of coal generates heat; and in burning the coal undergoes a chemical change; such a change is called chemical action. It is a form of energy. The well known law is that energy can never be created or destroyed but it can, however, be changed into some other form and exists in a variety of forms.
Note on the Text
c.g.s. system = centimeter-gram(me)-second system
Words to be Learnt
act v destroy v horse power
allow v drive (drove, driven) v make v
car n enable v move v
cause v exert v permit v
climb v floor n piston n
common a force v, n rest n
current n sense n
store v store v
undergo (underwent, undergone) v
velocity n
whenever cj
Answer the Questions
1. When does an agent do mechanical work? 2. What units of work are in common use? 3. What is power? 4. What units of power do you know? 5. What is one horse power equal to? 6. In what units is the power capacity of a dynamo electric generator universally expressed? 7. What is energy? 8. In what units is it expressed? 9. What is kinetic energy? 10. What energy do we call potential? 11. What forms of energy do you know?
What can you say on the following
1. Hot steam is able to do work; and we may say heat is a form of energy. Why?
2. Energy can never be created or destroyed. Why?
Text 4
ELECTRICAL CONDUCTION IN GASES
1. For a long time gases were supposed to be perfect insulators. Dry air and other gases seemed to offer a high resistance to the flow of electric current. About 1900 the scientists performed experiments which showed gaseous ions to serve as carriers for the electric current.
2. The conduction of electric current in gases is not easily predictable since it depends on many variables. The resulting conduction may vary with the gas employed, the gas pressure, the potential between electrodes, the electrode material, the shape of electrodes, the distance between electrodes, the shape of the1 enclosing medium and other factors. Conduction in cases may be attained with either hot or cold cathodes, the action being different in each case. All this proves to be in contrast with the theory of conduction of electricity in solids.
Kinetic Theory of Gases
3. The molecules of a gas are in a constant state of motion similar to that of molecules in liquids and solids. These in gases enjoy a greater freedom of movement so that what is termed gas pressure is certainly the result of multiple impacts of gas molecules upon the walls of the enclosure. The simple kinetic theory of gases assumes the molecules to be small spheres which collide with each other in the course of their constant motion. The distance a molecule moves before it collides with another is called its free path. Obviously the lengths of paths vary greatly, some being relatively short and others long. A study of the distribution of these paths will give a mean length of free path or average path which is of importance in the theory of electrical conduction in gases. The mean length of free path depends on the gas pressure and rises in magnitude as the pressure falls and the molecules are farther apart. The mean length of free path will also depend upon the dimension of the molecules. Mean length of free path of gaseous molecules is of the order of (1) 0.02 to 0.22 mm3 for the pressure of 1 mm of mercury.
4. An electron projected in a gas will likewise collide with the molecules present. After its first collision it will bounce off in a new direction until it experiences a second collision and then in a new direction for a third collision, and so on. In this manner4 it will travel in a zigzag path through the gas. The distance between collisions is the length of free path for the electron. Since the electron has a smaller mass and a smaller diminution dimension than the molecules of gas, it will experience fewer collisions and will have a longer length of free path (approximately six times5 that of the molecule).
5. Thus a gas atom is capable of receiving, transporting, and releasing energy through rapid changes in its atomic structure. This property combined with its kinetic energy plays a very important part in electrical conduction in gases.
Notes on the Text
Of the order of – примерно
0.02 – point no ought two (нуль целого числа может не читаться)
mm – millimeter [ ] – миллиметр
In this manner – таким образом
Слово times означает раза, например, three times – три раза
Words to be Learnt
assume v length n
attain v magnitude n
carrier n multiple a
case n resistance n
collision n path n
dimension n sphere n
distribution n variable n
Answer the Question
1. What is gas? 2. What did the scientists’ experiments show? 3. What does the simple kinetic theory of gases assume? 4. Why does the mean length of free path depend on the gas pressure? 5. What is mean length of free path of gaseous molecules? 6. What property plays a very important part in electrical conduction in gases?
What can you say on the following
1. The conduction of electric current in gases is not easily predictable since it depends on many variables what variables do you know?
2. The lengths of paths vary greatly, some being relatively short and others long. Do you agree with it? Why?
Text 5
ELECTRICITY
1. Electricity has been known since the days of the ancient Greeks. The word “electricity” comes from the Greek word for amber. The Greeks discovered that, if a piece of amber was rubbed with fur, it would pick up bits of straw or other light-weight materials. Later scientists discovered that other materials would act like amber. They could be given charges of electricity. Charges of this kind are called charges of frictional, or static, electricity. They are not very useful.
2. In 1800 an Italian scientist named Volta found a way of getting an electric current. He invented an electric cell. But electricity became truly useful after Michael Faraday invented a machine to push electrons on their way. A machine which furnishes a current of electricity is called a generator. Today we use both cells and generators.
3. A battery is made up of two or more electric cells joined together. We use batteries in such things as portable radios, flash-lights, electric games, and automobiles. The current which comes to our houses, stores and offices and lights our streets comes from generators.
4. In buying and using electrical appliances there are some terms everyone needs to know. “Volt is one”. “Ampere” is another. “Watt” is the third. The push that forces a current through a circuit is measured in volts. A volt is a measure of electrical force. Most household appliances are built for a voltage of either 127 or 220.
5. An ampere is a measure of the strength of a current. Electric lamp bulbs are marked in watts. A watt is a measure of electrical power. A kilowatt is 1,000 watts.
Words to be Learnt
amber n frictional electricity
ampere n furnish v
appliance n static a
built v volt n
cell n watt n
charge n
circuit n
Answer the Questions
1. Since when has electricity been known? 2. What did the Greeks discover? 3. Who found a way of getting an electric current? 4. What did M. Faraday invent? 5. What terms does everyone need to know in buying and using electrical appliances? 6. What is an ampere? 7. What is a measure of electrical power?
What can you say on the following
1. The word “electricity” comes from the Greek word for amber. What do you know about it?
2. In buying and using electrical appliances there are some terms (“Volt”, “Ampere” and “Watt”) everyone needs to know. Why?
Text 6
ELECTRICITY + AND –
1. When two different substances are rubbed together and then separated, both are found to be electrified one with one kind of electricity and the other with another. To illustrate this, one end of a rubber rod is charged by rubbing with fur and is then suspended in a small wire stirrup.
2. When the electrified end of a similarly charged rod is brought close by, the suspended rod turns away, showing repulsion. If the fur is brought close by, in place of the rubber, the suspended rod is attracted and turns toward the fur. When a glass rod, previously rubbed with silk, is brought close by, there is attraction, and when the silk is brought up there is repulsion.
3. Since the fur, as well as the glass, attracts the electrified rubber rod, they each have the same kind of electrification: they are said to be positively charged. By similar notation the rubber and silk by their actions are said to be negatively charged. Positive charges are designated by a (+) sign and negative charges by a (-) sign.
4. The above experiments indicate the existence of two kinds of electrification; they also demonstrate a rule concerning the action of one kind of electrification on another. Two negative charges repel each other. Positive and negative charges attract each other. Two positive charges repel each other. The general law can therefore be stated like that.
Words to be Learnt
action n positive a
attract v rub v
charge v rule n
electricity n repel v
existence n sign n
negative a substance n
Answer the Questions
1. When are two different substances found to be electrified? 2. With what kinds of electricity are they found to be electrified? 3. In what way is it illustrated? 4. In what way is the repulsion and the attraction shown? 5. Under what conditions are rubber and silk said to be negatively charged? 6. In what way is the rule of the action of one kind of electricity on another demonstrated? 7. What does the general law state?
What can you say on the following
Two negative charges repel each other. Why?
Positive and negative charges attract each other. Why?
Text 7
WHAT IS AN ELECTRIC CURRENT?
The question is often asked: “What is an electric current?” If we could examine the inside of a copper wire while a current is flowing, we should see an electron, leaving one copper atom, moving over to the next copper atom and so on.1 This stream of electrons moving along from atom to atom is called an electric current. The practical unit of current is called the ampere.
No one has ever seen an electric current. We only know of the existence of a current owing to its effects. A current can heat a conductor, it can have a chemical action when passing through a solution, or it can produce a magnetic effect. We can measure currents by observing their heating, chemical or magnetic effects.
Two things are necessary to cause an electric current to flow: first – a complete circuit, and second – a driving force2 called the electromotive force (e.m.f.).
If we were to put free electrons on an insulated copper ball, what would they do? In this case they would try to repel each other.
In case we connected this charged ball to another ball of equal size by a copper wire, what would be the result? The electrons would move along the copper wire until the number of electromotive force causing a current to flow.
A battery has a surplus of electrons on one its two plates; so we say that a battery furnishes an e.m.f.
If a copper wire is run from one plate to the other, a current flow in the complete circuit thus made. If a small bulb is placed in the complete circuit thus made. If a small bulb is placed in the circuit, it will light up, giving evidence to a current flow.
If the battery was disconnected and a generator substituted for it, we should have a typical lighting system. Both batteries and generators are the most common sources of electromotive force. The practical unit of e.m.f. is the volt.
Current will flow more readily in some substances than in others, that is, various substances offer lesser or greater resistance to the flow of current. The practical unit of resistance is the ohm. An application of Ohm’s 3 law tells us that an e.m.f. of l volt will produce a current of l ampere in a wire which has a resistance of l ohm.
Symbolically, Ohm’s law is often written
V potential difference4 R= — — or resistance = ————————-
I current
Such substances as porcelain, ebonite, rubber, glass and the like5 having extremely high resistance are known as insulators.
Substances whose properties lie between those of conductors and insulators are called semiconductors. Let us name but a few most widely used at present, they are germanium, silicon, selenium and copper oxide. The importance of semiconductors in our life cannot be overestimated. But for these tiny “workhorses” electronic industry would not have achieved such a great progress.
Notes on the Text
and so on – и так далее
driving force – движущая сила
Georg Ohm (1787-1854) – немецкий физик
V
R=— — resistance is equal to potential difference di-
I
vided by current
and the like – и другие подобные (вещества)
Words to be Leart
attract v side adv, prp repel v
bulb n insulate v semiconductor n
charge n, v like a silicon n
circuit n oxide n stream n
complete a plate n thus adv
evidence n readily adv typical a
examine v
and so on
and the like
that is = i.e. то есть
Answer the Questions
1. What is an electric current? 2. What is the unit of current? 3. What can an electric current do? 4. What is necessary to cause an electric current to flow? 5. What are the most common sources of electromotive force? 6. How does current flow in various substances? 7. What is the unit of resistance? 8. What substances do we call insulators? 9. What semiconductors do you know?
What can you say on the following
The practical unit of current is called the ampere. Why?
2. Two things are necessary to cause an electric current to flow. Can you call them?
Problems
1). A copper wire is 3 mm in diameter and 8 km long. What is its resistance? (Ans. 19.5).
2). A positive charge of + 12 х 10 is located 6 cm from a negative charge – 8 x 10. Calculate the force in N exerted by either charge upon the other.
Text 8
CONDUCTORS AND INSULATORS
1. Not all substances are good conductors of electricity. As a general rule, metals are good conductors whereas nonmetals are poor conductors. The poorest of conductors are commonly called insulators, or nonconductors.
2. The property of electrical conduction can be illustrated by an experiment. One end of a long thin copper wire is connected to an electroscope and the other end to a small brass knob mounted on a glass pedestal. When a charged rubber rod is touched to the knob, the gold leaf of the distant electroscope rises immediately. Electrons have been conducted along the wire. If a positively charged rod contacts the knob, electrons flow away from the electroscope, leaving the gold leaf with a positive charge.
3. If the copper wire in the above experiment is replaced by a nonconductor like a silk thread, the electroscope cannot be charged by the rod contacting the distant knob. Poor conductors, such as glass and amber, are used to support metal parts of electrical apparatuses for them to be insulated from unnecessary losses of electricity. For an electroscope to retain its electric charge the gold leaf and stem are insulated from the electroscope case with amber.
4. The difference between a conductor and insulator, or dielectric, is that in a conductor there are free electrons, whereas in an insulator all of the electrons are tightly bound to their respective atoms. In an uncharged body, there are an equal number of positive and negative charges. In metals a few of the electrons are free to move from atom to atom, so that when a negatively charged rod is brought to the end of a conductor, it repels nearby free electrons in the conductor and causes them to move. They in turn repel free electrons in front of them and give rise to a flow of electrons all along the conductor. Hence it is not necessarily the electrons from the charged rubber rod that reach the electroscope leaf, but rather the electrons from the end of the wire where it touches the electroscope knob.
5. There are a large number of substances that are neither good conductors of electricity nor good insulators. These substances are called semiconductors. In them, electrons can move only with some difficulty, i. e., with considerable force.
Words to be Learnt
conductor n insulator n
connect n knob n
considerable a move v
copper n property n
dielectric n rod n
electroscope n semiconductor n
insulate v wire n
Answer the Questions
1. Metals are good conductors, aren’t they? 2. What substances are called insulators? 3. What poor conductors do you know? 4. What is the difference between a conductor and insulator? 5. What substances are called semiconductors?
What can you say on the following
1. Not all substances are good conductors of electricity. Why? 2. The property of illustrated by an experiment? Do you know this experiment?
Text 9
PROPERTIES OF LIGHT
1. Light and its various phenomena present some of the most interesting studies in the whole realm of physics. They are interesting because the results of many experiments are revealed through the sense of vision as color phenomena. Equally important and every bit as interesting is the historical development and discovery of the various principles, concepts, and properties of light which give rise to these phenomena.
2. All of the various known properties of light are conveniently` described in terms of the experiments by which they were discovered and the many and varied experiments by which they are now continually demonstrated. Numerous as they are, these experiments may be grouped together and classified under one of the three following heads: 1) geometrical optics, 2) physical optics, and 3) quantum optics. Each of these may be subdivided as follows: geometrical optics: rectilinear propagation, finite velocity, reflection, refraction; physical optics: diffraction, interference, polarization, double refraction; quantum optics: diffraction, interference, polarization, double refraction; quantum optics: photoelectric effect, Compton effect, atomic excitation, pair production.
The Rectilinear Propagation of Light
3. The rectilinear propagation of light is another way of saying that “light travels in straight lines”. The fact that objects may be made to cast fairly sharp shadows is an experimental demonstration of this principle. Another illustration is the image formation of an object produced by light passing through a small opening. An object can be an ordinary incandescent light bulb. In order to see how an image is formed, consider the rays of light emanating from a single point a near the top of the bulb. Of the many rays of light radiating in all directions, the ray that travels in the direction of the hole passes through to the point a near the bottom of the bulb and passing through the hole will arrive at b near the top of the image screen. Thus it may be seen that an inverted image is formed.
4. If the image screen is moved closer to the pinhole screen, the image will be proportionately smaller, whereas if it were moved farther away the image would be proportionately larger. The same thing happens when either the object or the pinhole is moved. Excellent photographs can be made with this arrangement by making a pinhole in one end of a small box and placing a photographic film or plate at the other. Such an arrangement is called a pinhole camera. For good, sharp photographs the hole must be very small, because its size determines the amount of blurring produced.
Words to be Learnt
arrangement n light n
color n optic n
discover v property n
effect n refraction n
experiment n reflection n
image a result n
hole n screen n
Answer the Questions
1. How may be classified the experiments of light? 2. What is another way of saying that “light travels in straight lines”? 3. How can be made excellent photographs? 4. What arrangement is called a pinhole camera?
What can you say on the following
Light presents some of the most interesting studies in the whole realm of physics. Why? 2. For good, sharp photographs the hole must be very small. Why?
Text 10
REFRACTION
THE SPEED OF LIGHT
IN STATIONARY MATTER
1. History tells us that Galileo once tried to measure the speed of light, but without success. Galileo stationed himself on a hilltop with one lamp and an assistant on another hilltop with a similar lamp. Galileo would first uncover his lamp for an instant, sending a short flash of light to the assistant. As soon as the assistant saw this light he uncovered his own lamp, sending a flash back to Galileo, who noted the total time elapsed. After numerous repetitions of this experiment at greater and greater distances between observers, Galileo came to the conclusion that they could not uncover their lamps fast enough and that light probably travels with an infinite speed. Knowing as we do now that light travels with the amazing speed of 183,300 mi/s, it is natural that Galileo’s experiment should have failed.
2. In 1850, Foucault completed and published the results of an experiment in which he had measured the speed of light in water. This was a crucial experiment, for it settled a long existing controversy concerning the nature of light. According to Newton and his followers, light was believed to be made up of small particles or corpuscles emanating from a source. Huygens, on the other hand, regarded light as being composed of waves, similar in nature perhaps to water or sound waves. Now, Newton’s corpuscular theory required light to travel faster in a dense medium like air, whereas Huygens’ wave theory required it to travel slower. By sending light back and forth through a long tube of water, Foucault found its speed to be less than that in air. This was a strong confirmation of Huygens’ wave theory.
3. Years later, Michelson also measured the speed of light in water and found a value of 225,000 km/s. This is just 3/4 the speed in a vacuum. In common glass, the speed is still lower, being about 2/3 the speed in vacuum, or 2000,000 km/s. In air, the speed is very little less than the speed in a vacuum, differing only by about 70 km/s at sea level and less at higher altitudes where the air is less dense. For most practical cases this difference can be the same as in a vacuum.
Words to be Learnt
refraction n
experiment n speed n
flash n theory n
hilltop n vacuum n
level n value n
measure v wave n
particle n
Answer the Questions
1. Who tried to measure the speed of light? 2. Do you know how did Galileo do hic experiment? What was his result? 3. Who measured the speed of light in water? What were their results? 4. What is the speed of light?
What can you say on the following
1. Galileo’s experiment should have failed. Why?
The speed light in air is the same as in a vacuum. Is it so? Why?
Text 11
THE RAINBOW
1. The rainbow is nature’s most spectacular display of the spectrum of white light. The required conditions for the appearance of the phenomenon are that the sun is shining in one part of the sky and the rain be falling in the opposite part of the sky. Turning one’s back to the sun, the bright primary bow and sometimes the fainter secondary bow, with colors reversed, are seen as the arcs of circles. From a high point or an airplane, these bows may form complete circles whose common center lies in the direction of the observer’s shadow.
2. The elementary theory of the rainbow was first given by Antonius de Demini in the year 1611 and later developed more exactly by Descartes. The general characteristics of the primary and secondary bows are satisfactorily accounted for by considering only the reflection and refraction of light by spherical raindrops. To understand how the phenomenon arises, we first confine our attention to an individual raindrop. A ray of sunlight is shown entering a single raindrop at a point A near the top. At this point some of the light is reflected (not shown), and the remainder is refracted into the liquid sphere. At this first refraction the light is dispersed into its spectrum colors, violet being deviated the most and red the least.
3. Arriving at the opposite side of the drop, each color is partly refracted out into the air and partly reflected back into the liquid. Reaching the surface at the lower boundary, each color is again reflected and refracted. This second refraction is quite similar to that of a prism, where refraction at the second surface increases the dispersion already produced at the first. This is the path of the light in thousands of drops giving rise to the bright primary rainbow.
Words to be Learnt
appearance n path n
bow n primary a
circle n prism n
deviate v rainbow n
display n reflect v
drop n refract v
fall (fell, fallen) v spectrum n
liquid n
Answer the Questions
1. What is the rainbow? 2. What are the required conditions for the appearance of the phenomenon? 3. Who gave the elementary theory of the rainbow in 1611? 4. What are the general characteristics of the primary and secondary bows? 5. How does the rainbow arise? 6. How many colours has the rainbow got? Name them.
What can you say on the following
1. The rainbow is nature’s most spectacular display of the spectrum of white light? Do you agree with it? Why?
Text 12
THE ELECTRON
1) J.J. Thomson, who identified the cathode rays as streams of electrons, was Professor of Physics at the Cavendish Laboratory, in Cambridge. In this Laboratory Thomson began a study of cathode rays. He designed an improved discharge tube with which he could measure some of the fundamental characteristics of the stream of electrical particles that formed the cathode rays.
2) Thomson allowed the rays to flow past metal plates charged with electricity, and noted how the rays were deflected from their normal course. By careful measurement of the amount of the deflection he was able to work out exactly how much electricity was associated with a definite weight of cathode-ray particles. He estimated that the electric particle was about one-thousandth as heavy as the atom of hydrogen, which is the lightest of all atoms.
3) Thomson was convinced that he had made a fundamental discovery; he had proved that the cathode rays consisted of a stream of particles, and each particle carried a definite electric charge, which ha characteristics associated with matter. This idea of a particle of electricity was not new. But Thomson characterized the particle and gave it a definite personality.
Words to be Learnt
cathode n electron n
charge n estimate v
consist of v particle n
definite a ray n
deflect v stream n
tube n
Answer the Questions
1. In what way did Thomson identify the cathode rays? 2. What did he design and he improved discharge tube for? 3. In what way did Thomson allow the rays to flow? 4. What did he note concerning the direction of rays? 5. What was he able to do by measurement of the amount of the deflection? 6. How heavy was the electric particle? 7. What did Thomson prove? 8. What characteristics did the particle have? 9. What did J.J. Thomson discover?
What can you say on the following
1. Thomson had proved that the cathode rays consisted of a stream of particles. In what way?
His idea of a particle of еelectricity was not new. Why?
Text 13
PEACEFUL ATOMS
Achievements in studying atom structure have opened up new, practically unlimited possibilities to humanity for further mastering of nature’s forces. The discovery of atomic energy provides as profound effect for the benefit of civilization1 as the discovery of fire and electricity.
After having recovered from the shock of unimaginable horror of the explosion of the atomic bomb over Hiroshima people asked scientists how soon they would be able to apply the immense power of fashioned nucleus to peaceful purposes. Many problems had to be solved: the main one was that of “braking” the released neutrons efficiently so that the chain reaction could be controlled.
The “classical” solution of this question is conducting the heat generated by the fission process out of the reactor, making it boil water and forcing the resulting steam to drive turbines which, in their turn2, drive electric generators. It is a way which works well although it is still rather expensive.
It is to be noted that the first atomic power station fed by atomic fuels started working in the Soviet Union in 1945. Its capacity was 5, 000 kilowatts. The capacity of Novovoronezhskaya atomic power station built ten years later was already 210, 000 kilowatts. For generating 210, 000 kilowatts of electricity it took only 800 grammas of uranium 235 a day. By the 1-st of January 1970 the second section of this station had been put into operation and its capacity was 375, 000 kilowatts.
At the same time with large atomic stations smaller mobile electricity producing units have been created based on the discovery of radio-active sources — isotopes. A mobile atomic power station which weighs only 350 tons has been operating for some years in Obninsk near Moscow. It has a capacity of 1, 500 kilowatts and is operated only by three or four men during a shift. Mobile nuclear installations may be carried by rail and then by transporters to the out-of-the-way regions 3 even in areas having no roads. Such a station according to estimates can operate without being recharged for two years.
Nuclear power is still in roughly4 the same early phase as steam was at the beginning of the 19th century. Scientists are looking for new more efficient nuclear processes of producing energy. But it was only lately that the physicists understood that the process of producing tremendous energy by stars, including our Sun, was the very process they were looking for. Today we know that this thermonuclear process is called fusion and it takes place at fantastically high temperatures. It can be done only by imitating on the Earth the process that makes the Sun shine.
There are many difficult problems to overcome before thermonuclear power stations based on this process can become a reality, but the problem of fuel supply is the least of them: the oceans of the Earth are practically an inexhaustible source of deuterium which plays the decisive part in the fusion process and its extraction from sea water is neither complicated nor expensive.
In short, 5 peaceful uses of atomic energy are vast – but we must stop using it on weapons of mass annihilation.
Notes on the Text
provides as profound effect for the benefit of the civilization – оказывает такое же глубокое влияние на развитие цивилизации
in the turn – в свою очередь
out-of-the-way regions – отдаленные районы
roughly – грубо говоря
In the short – короче говоря
Words to Be Learnt
although adj feed (fed) v profound a
beginning n fission n, v purpose n
brake v fusion n rather adv
decisive a humanity n recharge v
efficiently adv (in)exhaustible a recover v
explosion n lately adv region n
extraction n possibility n release v
road n shine (shone) v supply n
according to turn n
In one’s turn
To take place
Answer the Questions
1. What possibilities have the achievements in the study of atom structure opened up? 2. What question did people ask scientist after the explosion of the first atomic bomb? 3. What was the main problem in applying the immense power of fashioned nucleus to peaceful purposes? 4. When and where did the first atomic power station start working? 5. What was its capacity? 6. When were the first and the second sections of Novovoronezhskaya atomic power station put into operation? 9. What kind of atomic station has been operating for several years in Obninsk? 10. Why are mobile nuclear installations convenient? 11. How long can they operate without being recharged? 12. What thermonuclear process takes place at fantastically high temperatures? 13. What element plays the decisive part in fusion process? 14. What can this element be extracted from?
What can you say on the following
1. We know that the thermonuclear process is called fusion and it takes place at fantastically high temperatures. Why?
2. We must stop using atomic energy on weapons of mass annihilation. Why?
Text 14
SOLAR ENERGY
1. Ever since it became apparent that the supply of coal, oil and natural gas would soon become inadequate for our needs, scientists have intensified their search for other sources of energy. It is natural, then, that the investigators should turn to the Sun which has been providing the Earth with enormous quantities of energy in the form of light and heat ever since it was created.
2. The Sun is the most important body in the Universe for mankind, for it gives us heat without which the Earth would be a frozen world in which no life can exist. The Sun is our closest star. Of course, you never should look directly at the Sun on a clear day. Although it is 93, 000, 000 miles away, it is so bright that it would damage your eyes.
3. The Sun is really a huge globe with a diameter of about 865, 000 miles. It would take over 100 Earths, side by side, to reach across the Sun at the equator. It the Sun were a hollow ball, you could pack more than 1, 300, 000 Earths inside it.
4. It was natural for early men to regard the Sun as a god. Indeed, it would have been strange if they had not done so, since we depend entirely upon the Sun for our light and heat, and without it no life on Earth could ever have developed.
5. A better idea of the Sun’s size will be gained if we describe a simple though impossible experiment. Suppose, that we could take an airplane to the Sun, and fly once round the solar equator, moving at a steady speed of 500 m. p. h.; it would take us 230 days. For almost eight months we would fly at this tremendous rate before arriving back at our starting point. Yet to go round the Earth at same speed would take us only a little more than 50 hours.
6. The Sun’s mass is over 330, 000 times that of the Earth, and the gravitational pull is extremely strong. If a man could stand on the solar surface, he would seem to weigh 2 ½ tons, so that he would be crushed under his own weight. However, we can hardly hope to visit the Sun, where the surface temperature is almost 6, 000 degrees Centigrade.
7. Until it became possible to form some ideas of the size of the Universe, men were inclined to think that the solar system was really important – just as a man who has lived all his life in a remote country village may think that the scattered houses which make up his own village are far more important than distant London. Nowadays, we know the solar system to be merely our “village in space”.
Words to be Learnt
adequate a indeed adv
apparent a intense a
crush v intensify v
exception n pull n
faint a regard n
fusion n scatter v
gain v strange a
hollow a surprise n
incline v
Answer the Questions
1. What sources of energy do you know?
2. Why is the Sun the most important body in the Universe for mankind?
3. What is our closest star?
4. What is a distance between our planet and the Sun?
5. What is a diameter of the Sun?
6. Which mass is bigger? (the Sun’s mass or the Earth’s mass)
7. What is the surface temperature of the Sun?
What can you say on the following
1. It became apparent that the supply of coal, oil and natural gas would soon become inadequate for our needs. Why?
2. Without the Sun no life on Earth could ever have developed. Why?
Text 15
1. The term laser derives its name from the description, Light Amplification by Stimulated Emission and Radiation. In principle the laser is a device that produces an intense, concentrated, and highly parallel beam of light. So parallel would be the beam from a visible light laser 1 ft in diameter that at the moon the beam would be no more than a mile wide.
2. Lasers are of three general kinds, those using solids, those using liquids, and those using gases. For the case of liquid or gas lasers, a Fabry – Perot interferometer, with silvered end plates is filled with a fluid. In the solid laser, the ends of a crystal are polished and silvered. Since the first successful laser was made with a large single crystal of ruby, this device will be explained as representative of solid state lasers.
3. The atomic lattice structure of a ruby crystal has the properties of absorbing light of absorbing light of certain frequencies and, of holding this absorbed energy for a period of time. Then by bouncing light of a different frequency back and forth between the silvered ends, the excited atoms may be stimulated to emit their stored energy as light of the same frequency and in exact phase with the original light waves. As these intensified waves bounce back and forth, they stimulate others, thus amplifying the original beam intensity.
4. Because the light waves emerging from the end of the laser are all in phase, the beam is said to be coherent, and the angular spread of the light is given by the relation
2. 44
Q = ———- where Q is in radians, is the wavelength of light,
d
and d is the diameter of the emergent beam. This equation arises from the treatment of the emergent beam. This equation arises from the treatment of the diffraction of light by a circular aperture.
Words to be Learnt
absorb v frequency n
amplification n liquid n
aperture n relation n
beam n ruby a
cohere v solid n
derive n structure n
diffraction n term n
emission treatment n
equation n wavelength n
Answer the Questions
1. What does the laser produce?
2. Are lasers of three general kinds? What are they?
3. What do know about liquid lasers?
4. What properties do the atomic lattice structures of a ruby crystal have?
2, 44
5. What does it mean Q = ——— ?
d
1. A ruby laser produces a beam of red light of wavelength 69 43 A, with a circular cross section 1/8 in. in diameter. Find the diameter of this beam at a distance of 100 mi.
2. A ruby laser produces a beam of red light of wavelength 69 43 A, with a circular cross section 1 cm, in diameter. Find the diameter of this beam at a distance of 1000 km. (Ans. 169 m).
Scientists of different countries are successfully developing quantum generators, called lasers1, and are looking for practical uses for a new kind of ray which is millions of times brighter than the Sun.
Atoms emit rays of different length which prevents the forming of an intense beam of light. The laser forces its atoms to emit rays having the same length and traveling in the same direction. The result is a narrow, extremely intense beam of light that spreads out very little and is therefore able to travel very great distances.
Lasers being employed in the metal-working industries, in medicine, in the study of space are of various sizes, big and small, the latter2 demonstrating their power and numerous applications in many industries.
For instance, in two-millionths of a second a laser beam can cut a hole through a laser beam can cut a hole through a diamond, the hardest of all known minerals. With great speed and precision it burns holes in thick steel girders and instantly welds together pieces of metal, etc.
The first laser having been built in 1960, scientists developed several types of lasers which make use of luminescent crystals, luminescent glass, a mixture of various gases and finally semiconductors.
Having been developed at the Lebedev Institute of Physics in 1962, semiconductor quantum generators occupy a special place among the optical generators. While the size of a ruby crystal laser comes to tens of centimeters and that of a gas generator is about a meter long, a semiconductor laser is a few tens of a millimeter long, the density of its radiation being hundreds of thousands of times greater than that of the best ruby lasers.
But the most interesting thing about semiconductor lasers is that they are able to transform electric energy directly into light wave energy. They perform it with an efficiency approaching 100 per cent as compared with a maximum of about I per cent of other lasers, this property of semiconductor lasers opening up new possibilities of producing extremely economical sources of light.
But it is in the field of communications that the laser will find its most extensive application in future. Scientists foresee the day when a single laser beam will be employed to carry simultaneously millions of telephone conversations or a thousand of television programmers. It will serve for fast communications across continents, under the sea, between the Earth and spaceships and between men traveling in space.
The potential importance of these applications continues to stimulate new developments in the laser field.
1. laser – слово лазер состоит из начальных букв фразы, описывающей функцию прибора: light amplification by stimulated emission of radiation – усиление света посредством стимулирования эмиссии излучений
2. the latter – последний (из двух названных); ср.: the former – первый (из двух названных)
conversation n foresee (foresaw, foreseen) v
describe v girder n
diamond n hole n
finally adv narrow a
perform v
prevent v
the former … simultaneously adv
the latter … single a
spread (spread) v
travel v
weld n,v
1. What is a laser? 2. What is the function of a laser? 3. What beam of light does a laser produce? 4. Where are lasers employed? 5. What can it do? 6. When was the first laser built? 7. What types of quantum generators did scientists develop after 1960? 8. What is the most interesting type of lasers? 9. Where will a laser find the most extensive applications in future?
1. A semiconductor laser is a few tens of a millimeter long, the density of its radiation being hundreds of thousands of times greater than that of the best ruby lasers. Why?
2. The laser will find its most extensive application in future. Why?
SUPPLEMENT 1
MATHEMATICAL EXPRESSIONS
Addition: 3 + 5 = 8 + plus
Subtraction: 10 – 7 = 3 — minus
Ten minus seven are (или is; is equal to) three.
3 is the difference.
Multiplication: 4 x 6 = 24 x times
Four times (или multiplied by) six is twenty-four.
24 is the product.
Division: 21: 3 = 7 : divided by
Twenty-one divided by three is seven.
7 is the quotient.
1 (1/2) – a half или one half 3 (3/5) – three fifths
2 5
5 1 — five and a (one) half
(2/3) – two thirds 2
3
Decimal Fractions
zero – point – three
eleven – point – zero – five
nineteen – point – twelve
zero – point – eight – three – five
SUPPLEMENT 2
DO YOU KNOW THAT…
| Meaning | Example | |
| micro | 0.000001 or 10-6 | microwatt, microfarad |
| milli | 0.001 or 10-3 | millimetre, milliampere |
| centi | 0.01 | centimetre, centigrade |
| deci | 0.1 | decimetre, decimal |
| hecto | 100 | hectowatt |
| kilo | 1,000 or 103 | kilowatt, kilocycle |
| mega | 1,000,000 or 106 | megacycle, megohm |
… the Moon is the Earth’s natural satellite and is the nearest to in space?
… the Moon’s nearest distance to the Earth is 221, 463 miles?
… it is 2,163 miles in diameter; its mass is 1/81 that of the Earth?
… the flights of Soviet space rockets to the Moon began on January 2, 1959?
… the first man-made Moon satellite was Luna 10 (April, 1966)?
… the first people landed on the Moon on July 20, 1969? They were three American cosmonauts form the spaceship Apollo 11.
… most of metals are silvery white or grey in colour? Copper is the only red metal, and gold is the only yellow one.
… the critical temperature of steel is the temperature above or below which the molecular structure changes?
… the critical temperature of a gas is the temperature above which it cannot be liquefied by pressure?
… the critical pressure is the pressure at which gas can be liquefied?
… M. V. Lomonosov (1711-1765) was the first in Russia to make experiments with atmospheric electricity and to equip a laboratory for investigating electrical phenomena?
… V. V. Petrov (1761-1834) discovered the electric arc and indicated the possibilities of its utilization as a source of heat and light?
… P. N. Yablochkov (1847-1894) invented the “Russian candle” (known abroad as “Russian light”) which was the first source of electric light?
… F. N. Lodygin (1847-1923) is the inventor of the incandescent lamp, the most common source of electric light?
… it was A. S. Popov (1859-1906) who invented the radio in 1895? His work laid the foundation for further inventions and improvements in the field of radiotelegraphy, broadcasting, television, radiolocation and so on.
… only about 200 of the brighter stars have been given individual names?
… people began to give name to the stars about 2,000 years ago?
… the Sun is the star nearest the Earth, the mean distance from the Sun to the Earth is 93 million miles?
… on a clear night man can see with a naked eye about 4,000 stars?
… a star’s brightness depends upon three factors: its distance from us, its temperature and its size? The nearer the star, the brighter it looks. From stars of the same size and at the same distance, the hotter stars will be the brighter.
… there are stars of different colours-red, orange, yellow, white and blue? More seldom we can see violet and green stars.
… the hottest stars have a surface temperature about 80,000 Fahrenheit, the coolest visible stars are about 3,000 Fahrenheit at their surface?
SUPPLEMENT 3
“How new inventions that change the face of the world are made?” somebody asked Einstein. “Quite simply,” answered Einstein. “Everybody knows that something is impossible. Then guide by chance 1 there happens an ignorant man who does not know it and he makes the invention.”
During his visit to an observatory Einstein got interested in the gigantic telescope with a mirror of 2.5 meters in diameter.
“What do you need such a big instrument for?” asked Einstein’s wife.
“We use it to study the structure of the universe,” answered the director of the observatory.
“Really?” said the lady. “My husband usually does it on the inside of an old envelope.
Notes on the Text
by chance – случайно
got interested — заинтересовался
Richard: Daddy, is it true that the law of gravity keeps us on the earth?
Father: Yes, that’s true.
Richard: What did we do before that law was discovered?
SCIENCE AND PROFIT 1
Faraday’s discoveries in the field of electromagnetism attracted much attention but their importance was little understood. One day a member of parliament visited Faraday and asked him to some of his experiments. Faraday demonstrated the phenomenon of induced currents.2 “What’s the use of it?” asked the visitor.
“Soon you will be able to tax it,”3 was the scientist’s answer.
____________
profit – прибыль
induced currents – возбужденный ток
to tax – облагать налогом
The famous English scientist Rutherford (1871-1937), the discoverer of the atomic nucleus, came to his laboratory ate in the evening. One of the pupils was still busy with the instruments.
“What are you doing here at such late time?” Rutherford asked the young scientist.
“I am working,” came the proud answer.
“And what do you do by day?”
“Work, of course.”
“And do you work early in the morning?”
“Yes, professor, I work early in the morning as well,” the pupil answered proudly.
Rutherford looked at him with some pity and asked: “And when do you think?”
Используемая литература
1. Андрианова Л.Н., Багрова Н.Ю., Ершова Э.В. Учебник английского языка для заочных технических вузов. 3-е изд., испр.- М.: Высш. Школа, 1980.- 480с.
2. Книга для чтения по физике на английском языке /Сост. Е.А. Хомутов, В.Л. Метлицкая.-М.: Изд-во Моск. ун-та, 1980.-114с.
3. Учебник английского языка для заочных технических вузов.- М.: Высш. Школа, 1974.-304с.
4. Хомутов Е.В. Интенсивный курс английского языка для физиков.-М.: Изд-во Моск. ун-та, 1983.-216с.
Introduction ……………………………………………….. 2
Text 1 PHYSICS AS AN OBJECTIVE METHOD ……… 3
Text 2 SOURCES OF POWER …………………………… 4
Text 3 WORK, POWER AND ENERGY………………… 6
Text 4 ELECTRICAL CONDUCTION IN GASES……… 8
Text 5 ELECTRICITY……………………………………. 10
Text 6 ELECTRICITY + AND – ………………………… 12
Text 7 WHAT IS AN ELECTRIC CURRENT? ………….. 13
Text 8 ONDUCTORS AND INSULATORS …………… 16
Text 9 PROPERTIES OF LIGHT ……………………….. 18
Text 10 REERACTIONTHE SPEEP OF
LIGHT IN STATIONARY MATTER …………. 20
Text 11 THE RAINBOW ………………………………… 21
Text 12 THE ELECTRON ……………………………….. 23
Text 13 PEACEFUL ATOMS …………………………… 24
Text 14 SOLAR ENERGY ……………………………… 27
Supplement 1 MATHEMATICAL EXPRESSION …….. 33
Supplement 2 DO YOU KNOW THAT… ………………. 34
Literature …………………………………………………. 37
43
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