III. Reading.

Exercise 1. Read and translate the text:

Text A.

Energy

In the language of science energy is the ability to do work. There are various forms of energy, such as heat, mechanical, electrical, chemical, atomic and so on. One might also mention the two kinds of mechanical energy—potential and kinetic, potential energy is the energy of position while kinetic energy is the energy of motion.

It is well known that one form of energy can be changed into another. A waterfall may serve as an example. When water fall from its raised position, energy changes from potential to kinetic energy. The energy of falling water is generally used to turn the turbines of hydroelectric stations. The turbines in their turn drive the electric generators, the latter producing electric energy. Thus, the mechanical energy of falling water is turned into electric energy. The electric energy, in its turn, may be transformed into any other necessary form.

When an object loses its potential energy, that energy is turned into kinetic energy. Thus, in the above-mentioned example when water is falling from its raised position, it certainly loses its potential energy, that energy change into kinetic energy.

We have already seen that energy of some kind must be employed to generate the electric current. Generally speaking, the sources of energy usually employed to produce current are either chemical, as in the battery, or mechanical, as in the electromagnetic generator.

The rising standards of modern civilization and growing industrial application of the electric current result in an increasing need of energy. Every year we need more and more energy. We need it to do a lot of useful things that are done by electricity. However, the energy sources of the world are decreasing while the energy needs of the world are increasing. These needs will continue to grow as more motors and melted metals are used in industry and more electric current is employed in everyday life. As a result, it is necessary to find new sources of energy.

The sun is an unlimited source of energy. However, at present, only a little part of solar energy is being used directly. How can we employ solar energy directly to produce useful energy? This is a question which has interested scientists and inventors for a long time. Lavoisier and other great scientists of the past melted metals with the help of solar furnaces. Today, solar furnaces illustrate just onem of the numerous ways to harness the sun. Using semiconductors, scientists, for example, have transformed solar energy into electric energy.

IV. Language.

Exercise 1. Find the correspondence:

1. to transform 1. служити

2. device 2. грати роль

3. application 3. пристрій, прилад

4. chemical 4. напівпровідник

5. potential 5. використовувати

6. source 6. джерело

7. station 7. що стосується

8. to produce 8. потенційний

9. to drive 9. застосування

10. to serve 10. перетворювати

11. to do without 11. станція

12. to make use of 12. виробляти

13. as for 13. хімічний

14. to play a part 14. обходитись без чого–небудь

15. semiconductor 15. приводити в дію

Exercise 2. Find the correct term out of the three given below:

1. The motor changes electrical energy into …

a) heat energy; b) chemical energy; c) mechanical energy.

2. The generator changes mechanical energy into …

a) chemical energy; b) electrical energy; c) light energy

3. The battery changes chemical energy into …

a) solar energy; b) heat energy; c) electric energy

4. The electric furnace changes electric energy into …

a) heat energy; b) mechanical energy; c) solar energy.

5. The vacuum cleaner changes electrical energy into …

a) light energy; b) mechanical energy; c) solar energy