Part b.

Exercise 1. Read and translate the text.

Heat and Temperature.

As we have just noted, there was a time when heat was supposed to be a sort of substance or fluid which flowed from a body of high temperature to one of lower temperature. That substance was given the name "caloric". At present, we know heat to be a form of energy and to be capable of performing work. Heat may be converted into mechanical energy and heat, in its turn, is generated when mechanical motion is destroyed by friction.

An object is said to be hot if its temperature is higher than that of our body, or cold if its temperature is much lower. If a hot body is brought into contact with a cold one, the hot body will cool and the cold body will become warmer. We explain it by the fact that the hot body has transferred some amount of heat to the cold one. If two bodies A and B are brought into contact and heat is transferred from A to B, we say that A is at a higher temperature than B, or that A is hotter than B.

Hot and cold are not very definite terms, nor are our temperature sensations very accurate. A room may seem to be warm when one enters it after being out in the cold. On the other hand it may seem to be cold after one has been near a hot furnace.

Our temperature sensations are found to be neither accurate nor reliable and the differences of temperature are generally defined by other means.

To measure temperature it is necessary to choose some kind of temperature scale. This may be done by means of some substance which changes with temperature changes. For example, a liquid such as mercury is known to expand when it is heated. Therefore, its change of volume due to heating is often used to measure the change of temperature (this is the principle the mercury thermometer is based upon).

Exercise 2. Read and translate the following words. Make up sentences using these words.

Amount, accurate, furnace, unreliable, liquid, mercury, thermometer, notice, different, measure, therefore, finger, definite, show, sensations, substance, know.

Exercise 3. Answer the following questions.

1. What does this article deal with?

2. What is heat?

3. Is heat capable of performing work?

4. When can you say that a body is hot?

5. Is heat a form of motion?

6. What happens when a hot body is brought into contact with a cold one?

7. Are out temperature sensations accurate?

8. Does mercury expand when heated?

9. What instrument is used for measuring temperature?

10. What principle is the mercury thermometer based upon?

Exercise 4. Translate the following sentence.

1. Відомо, що речовина складається з молекул.

2. Вважали, що теплород переходить від більш гарячого тіла до більш холодного.

3. Ми знаємо, що тепло це форма енергії.

4. Здається, температура води піднімається до 80⁰ С.

5. Відомо, що Ломоносов установив молекулярно-кінетичну теорію газів.

Exercise 5. Give equivalents of the words.

тепло, час, потік, тіло, речовина, форма, рух, руйнувати, тертя, пояснити, вищий, чашка, ртуть, читати.

Exercise 6. Form as many words as possible from the given below.

differ, accurate, worm, measure, high, object, transfer, place, rely.

Exercise 7. Annotate the text using the phrases.

The subject of this text is … ; The author described … ; The purpose of this article is … ; It is pointed out that … ; The author tells us about … ; The text also discusses … ; The next part of the text is devoted to … ; Further the author describes … etc.