Английский - 2курс_3семестр_physics

UNIT 4

Home-reading

Nobel Prize in Physics

Wilhelm Rontgen (1845 - 1923) was the first person to receive the Nobel Prize in Physics for his discovery of x-rays.

The Nobel Prize in Physics is awarded once a year by the Royal Swedish Academy of Sciences. It is one of the five Nobel Prizes established by the will of Alfred Nobel in 1895, awarded for outstanding contributions in physics, chemistry, literature, peace, and physiology or medicine since 1901. The first Nobel Prize in Physics was awarded to Wilhelm Conrad Rontgen, a German, ―in recognition of the extraordinary services he has rendered by the discovery of the remarkable rays (or x-rays).‖ This award is administered by the Nobel Foundation and widely regarded as the most prestigious award that a scientist can receive in Physics. It is presented in Stockholm at an annual ceremony on December 10, the anniversary of Nobel‘s death. In 2007 the Nobel Prize in Physics was awarded to Albert Fert (of France) and Peter Grunberg (of Germany) for the discovery of giant magneto resistance; they shared the prize amount of 10,000,000 SEK (slightly more than €1 million, or US$ 1.6 million).

In 2008 the Nobel Prize was awarded with one half to Yoichiro Nambu (USA)

―for the discovery of the mechanism of spontaneous broken symmetry in subatomic physics‖; and the other half jointly to Makoto Kobayashi (Japan) and

Toshihide Maskawa (Japan) ―for the discovery of the origin of the broken symmetry which predicts the existence of at least three families of quarks in nature‖.

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Nomination and selection

A maximum of three Nobel Laureates and two different works may be selected for the Nobel Prize in Physics. Compared with some other Nobel Prizes, the nomination and selection process for the Nobel Prize in Physics is long and rigorous. This is a key reason why these Nobel Prizes have grown in importance over the years to become the most important prizes in Physics.

These Nobel Laureates are selected by a committee that consists of five members elected by The Royal Swedish Academy of Sciences. In its first stage, several thousand people are asked to nominate candidates. These names are scrutinized and discussed by experts until only the winners remain. This slow and thorough process, insisted upon by Alfred Nobel, is arguably what gives the prize its importance.

Forms, which amount to a personal and exclusive invitation, are sent to about three thousand selected individuals to invite them to submit nominations. The names of the nominees are never publicly announced, and neither are they told that they have been considered for the Prize. Nomination records are sealed for fifty years. In practice some nominees do become known. It is also common for publicists to make such a claim, founded or not.

The nominations are screened by committee, and a list is produced of approximately two hundred preliminary candidates. This list is forwarded to selected experts in the field. They remove all but approximately fifteen names. The committee submits a report with recommendations to the appropriate institution.

While posthumous nominations are not permitted, awards can occur if the individual died in the months between the nomination and the decision of the prize committee.

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The Nobel Prize in Physics requires that the significance of achievements being recognized is ―tested by time.‖ In practice it means that the lag between the discovery and the award is typically on the order of 20 years and can be much longer. For example, half of the 1983 Nobel Prize in Physics was awarded to Subrahmanyan Chandrasekhar for his work on stellar structure and evolution that was done during the 1930s. As a downside of this approach, not all scientists live long enough for their work to be recognized.

Some important scientific discoveries are never considered for a Prize, as the discoverers may have died by the time the impact of their work is realized. The Nobel Award Ceremony

The committee and institution serving as the selection board for the prize typically announce the names of the laureates in October. The prize is then awarded at formal ceremonies held annually on December 10, the anniversary of

Alfred Nobel‘s death. ―The highlight of the Nobel Prize Award Ceremony in Stockholm is when each Nobel Laureate steps forward to receive the prize from the hands of His Majesty the King of Sweden. ... Under the eyes of a watching world, the Nobel Laureate receives three things: a diploma, a medal and a document confirming the prize amount‖ ("What the Nobel Laureates Receive").

The Nobel Banquet is the banquet that is held every year in Stockholm City Hall in connection with the Nobel Prize.

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PROBLEM SOLVING

1. Correct use of a calculator: (a) Calculate on a calculator. [Self-check: The most common mistake results in 97555.40.]

(b) Which would be more like the price of a TV, and which would be more like the price of a house, $3.5 × 105 or $3.55?

2.Compute the following things. If they don‘t make sense because of units, say so. (a) 3 cm + 5 cm; (b) 1.11 m + 22 cm; (c) 120 miles + 2.0 hours; (d) 120 miles / 2.0 hours

3.Your backyard has brick walls on both ends. You measure a distance of 23.4 m from the inside of one wall to the inside of the other. Each wall is 29.4 cm thick. How far is it from the outside of one wall to the outside of the other? Pay attention to the significant figures.

4.The speed of light is 3.0 × 108 m/s. Convert this to furlongs per fortnight. A furlong is 220 yards, and a fortnight is 14 days. An inch is 2.54 cm.

5.Express each of the following quantities in micrograms:

(a) 10 mg, (b) 104 g, (c) 10 kg, (d) 100 × 103 g, (e) 1000 ng.

6.Convert 134 mg to units of kg, writing your answer in scientific notation.

7.In the last century, the average age of the onset of puberty for girls has decreased by several years. Urban folklore has it that this is because of hormones fed to beef cattle, but it is more likely to be because modern girls have more body fat on the average and possibly because of estrogen-mimicking chemicals in the environment from the breakdown of pesticides. A hamburger from a hormone-implanted steer has about 0.2 ng of estrogen (about double the amount of natural beef). A serving of peas contains about 300 ng of estrogen. An adult woman produces about 0.5 mg of estrogen per day (note the different unit!). (a) How many hamburgers would a girl have to eat in one day to consume as much estrogen as an adult woman‘s daily production? (b) How many servings of peas?

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CHAPTER I. FORCE AND MOTION

UNIT 5

Force and Motion

Read the text and find the difference between Newton’s and Aristotle’s ideas.

If I have seen farther than others, it is because I have stood on the shoulders of giants.

Newton, referring to Galileo

Even as great and skeptical genius as Galileo was unable to make much progress on the causes of motion. It was not until a generation later that Isaac Newton (1642-1727) was able to attack the problem successfully. Newton discovered the relationship between force and motion and revolutionized our view of the universe by showing that the same physical laws applied to all matter, whether living or nonliving, on or off of our planet‘s surface. His book on force and motion, the Mathematical Principles of Natural Philosophy, was uncontradicted by experiment for 200 years.

Aristotle‘s ideas about the causes of motion were completely wrong, just like all his other ideas about physical science, but it will be instructive to start with them.

We need only explain changes in motion, not motion itself.

Aristotle thought he needed to explain both why motion occurs and why motion might change. Newton inherited from Galileo the important counterAristotelian idea that motion needs no explanation, that it is only changes in motion that require a physical cause. Aristotle‘s needlessly complex system

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gave three reasons for motion: 1) Natural motion, such as falling, came from the tendency of objects to go to their ―natural‖ place, on the ground, and come to rest; 2) Voluntary motion was the type of motion exhibited by animals, which moved because they chose to; 3) Forced motion occurred when an object was acted on by some other object that made it move.

Motion changes due to an interaction between two objects.

In the Aristotelian theory, natural motion and voluntary motion are onesided phenomena: the object causes its own motion. Forced motion is supposed to be a two-sided phenomenon, because one object imposes its ―commands‖ on another. Where Aristotle conceived of some of the phenomena of motion as onesided and others as two-sided, Newton realized that a change in motion was always a two-sided relationship of a force acting between two physical objects.

Forces can all be measured on the same numerical scale.

In the Aristotelian-scholastic tradition, the description of motion as natural, voluntary, or forced was only the broadest level of classification, like splitting animals into birds, reptiles, mammals, and amphibians. There might be thousands of types of motion, each of which would follow its own rules.

Newton‘s realization that all changes in motion were caused by two-sided interactions made it seem that the phenomena might have more in common than had been apparent. In the Newtonian description, there is only one cause for a change in motion, which we call force. Forces may be of different types, but they all produce changes in motion according to the same rules. Any acceleration that can be produced by a magnetic force can equally well be produced by an appropriately controlled stream of water. We can speak of two forces as being equal if they produce the same change in motion when applied in the same situation, which means that they pushed or pulled equally hard in the same direction.

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More than one force on an object.

Aristotle conceived of forced motion as a relationship in which one object was the boss and the other ―followed orders.‖ It therefore would only make sense for an object to experience one force at a time, because an object couldn‘t follow orders from two sources at once. In the Newtonian theory, forces are numbers, not orders, and if more than one force acts on an object at once, the result is found by adding up all the forces.

Objects can exert forces on each other at a distance.

Aristotle declared that forces could only act between objects that were touching, probably because he wished to avoid the type of occult speculation that attributed physical phenomena to the influence of a distant and invisible pantheon of gods. He was wrong, however, as you can observe when a magnet leaps onto your refrigerator or when the planet earth exerts gravitational forces on objects that are in the air. Some types of forces, such as friction, only operate between objects in contact, and are called contact forces. Magnetism, on the other hand, is an example of a noncontact force. Although the magnetic force gets stronger when the magnet is closer to your refrigerator, touching is not required.

Weight

In physics, an object‘s weight, FW, is defined as the earth‘s gravitational force on it. The SI unit of weight is therefore the Newton. People commonly refer to the kilogram as a unit of weight, but the kilogram is a unit of mass, not weight. Note that an object‘s weight is not a fixed property of that object.

Objects weigh more in some places than in others, depending on the local strength of gravity. It is their mass that always stays the same. A baseball pitcher who can throw a 90-mile-hour fastball on earth would not be able to throw any faster on the moon, because the ball‘s inertia would still be the same.

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Answer the following questions:

1)How did Newton revolutionize our view of the universe?

2)What did Newton inherit from Galileo?

3)What are three reasons for motion according to Aristotle?

4)What do you know about natural, voluntary and forced motion?

5)What types of motion can you name?

6)How did Aristotle conceive of forced motion?

7)Can forces only act between objects that are touching?

8)What is FW?

9)How many causes for a change in motion are there according to Newton?

10)What is the difference between terms ‗weight‘ and ‗mass‘?

Make a plan to the text and try to speak on the topic using this plan.

Write a short summary.

Look through the text and fill in the blanks with the proper information.

1)Aristotle‘s ideas about the causes of motion were completely … , just like all his other ideas about physical science, but it will be … to start with them.

2)In the Aristotelian theory, … motion and … motion are one-sided phenomena.

3)Any … that can be produced by a magnetic force can equally well be produced by an appropriately controlled stream of water.

4)In the Newtonian theory, forces are …, not orders, and if more than one

force acts on an object at once, the result is found by adding up all the … .

5)… is an example of a noncontact force.

6)The SI unit of weight is therefore the … .

7)Object‘s weight is not a fixed … of that object.

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You/We/They

Interrogative

I

you/we/they

Negative

I

He/She/It will not won‟t phone. You/We/They

Time Expressions

Time expressions used with the future indefinite include: tomorrow, the day after tomorrow, next week/month/year, tonight, soon, in a week/month/year, etc.

We use the future indefinite:

for future actions which may or may not happen.

We‟ll visit Disney World one day.

for predictions about future.

Life will be better fifty years from now.

for threats or warnings.

Stop or I‟ll shoot.

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for promises or on-the-spot decisions.

I‟ll help you with your homework.

with verbs hope, think, believe, expect, etc., the expressions I’m sure, I’m afraid, etc. and the adverbs probably, perhaps, etc.

I think he will support me.

He will probably go to work.

NOTE:

We do not use the future indefinite after: while, before, until, as soon as, after, if, and when. We use the present indefinite instead.

I‘ll make a phone call while I wait for you.

“When” can be followed by the future indefinite if it is used as a question word.

When will you return?

I don‘t know when Helen will be back.

“When” is followed by the present indefinite if it is used as a time word.

Please phone me when you finish work.

Will/Shall

We use:

Will you …? to ask someone to do something for us (request). Will you post these letters for me, please?

(= Can you post these letters for me, please?)

Shall I …? when we offer to do something for someone else. Shall I help you clean your room?

(= Do you want me to help you clean your room?)

Shall we …? to make a suggestion.

Shall we go to the theatre tonight?

(= Why don‘t we go to the theatre tonight?)

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