6. Переведите на английский язык

Британская тепловая единица, фунт на фут, лошадиная сила, нуль градусов, международная система измерения, Цельсий, кило - калория, шкала, скрытое тепло, явное тепло, удельное тепло (теплоемкость).

7. Ответьте на вопросы

1. What is temperature?

2. What is absolute temperature?

3. What is heat?

4. What is the latent heat?

5. What is sensible heat?

6. What is specific heat?

Text 4.VAPOR PRESSURE

1. Прочитайте текст, обращая внимание на незнакомые слова и выражения

Every liquid produces a vapor as the molecules near its surface free themselves from the attraction of their neighbors and fly off into space. This vapor exerts pressure on any containing vessel and the amount of pressure exerted by the vapor of any particular liquid depends solely on the temperature of the liquid surface; the higher the temperature, the greater the pressure. For any liquid a graph can be drawn showing the relationship between this vapor pressure and the temperature of the liquid surface.

How can gas be liquefied? When heat is removed from a gas its temperature is lowered until it reaches a value corresponding to the pressure (see above) after which further removal of heat liquefies the gas. Alternatively, an increase in pressure combined with removal of heat makes it possible to liquefy the gas without reducing its temperature.

What is superheated vapor? It is vapor removed from contact with its liquid and at a temperature higher than that which corresponds to its pressure as indicated by

the temperature-pressure-vapor relationship for that particular substance.

What is saturated vapor? It is vapor whose temperature and pressure are in accordance

with the temperature-vapor-pressure relationship for the particular substance. Vapor in contact with its liquid is saturated.

What is the numerical relationship between heat units and units of mechanical work? This can be expressed as follows:

1 Btu = 778 lbft. Thus, for example, the energy given up by a weight of 77.8 lb in falling 10 ft is sufficient to heat 1 lb of water through 1F. Again, since a horsepower (hp) is the rate of production of energy of an engine doing 33,000 lbft of work per minute, 1 hp =

33.000/778 or 42.4 Btu/min and therefore 2,545 Btu/h. The kilowatt (kw), (not kilowatt hour) is another unit of power and 1 kW = 1.34 hp or 3.410 Btu/h. Further, 1 kcal = 4.18 J, and 1 J/s = 1 W.

2. Прочитайте и переведите слова

Vapor, attraction, space, exert, contain, vessel, particular, graph, relationship, remove, correspond, alternatively, indicate, saturate, rate, power, pressure, kilowatt.

3. Прочитайте однокоренные слова и объясните способ их образования

Vapor – vaporize – vaporization

Attract – attractive – attraction

Contain – container – containment

Correspond – correspondence – correspondent

Indicate – indicator – indication

Saturate – saturator – saturation

Power – powerful – powerless

4. От существительных образуйте глаголы и переведите их на английский язык

Пар, притяжение, показание, насыщение, давление, соответствие, связь, сила.

5. Заполните пропуски необходимыми по смыслу словами

1. Every liquid produces ... (vapor, gas, fog).

2. For any liquid a ... can be drawn (table, picture, graph).

3. The higher the temperature of a liquid surface, the greater the ... (power, pressure, speed).

4. Vapor in contact with its liquid is ... (disappeared, saturated, overheated).

5. The rate of production of energy is ... (voltage, resistance, horsepower).

6. The kilowatt is another unit of ... (weight, velocity, power).