Question

The metric system

Physics measures such physical quantities as time, length, mass, density, velocity, area, volume, temperature and energy. Different units of length and mass exist. Nearly all of them are interrelated. Nowadays, three main systems of measurement are widely used: the British system of unity, the metric system of units and the International system of units (SI).

With а few exceptions, all the nations of the world use the metric system. It is so easy that anyone who knows arithmetic can learn it quickly. Before the introduction of the metric system (metre-kilogram-second), the British foot- pound-second system was widely used. But the latter system (which is still in use in Great Britain and the USA) was very complicated and caused serious difficulties in the international trade. For example, in the British system 1 mile is equal to 1760 yards, 1 yard - to feet and 1 foot- to 12 inches. This means that it's very difficult to convert units. But in the metric system each unit is а multiple of the following lower unit bу ten. Therefore, the conversion to а higher quantity is done bу moving the decimal point to the right to the required number of places, and vice versa.

The idea of decimal system was realized only at the end of the 18th century. In 1791, the French Academy of Science decided that the standard of length should bе one ten-millionth part of the distance from the Equator to the North Pole. The two French scientists charged with the task took this distance on а line running through Paris and divided it into 10 000 000 equal parts. They called one of the parts а metre ('measure'), which became the main unit. Metre was also used to measure area and volume. Thus а square metre and а cubic metre appeared.

The main advantage of the system is that for shorter measurements the metre is divided bу ten, so а decimal system was used. Shorter units had Latin prefixes and longer ones - Greek prefixes. So, 'millimetre' is Latin for 'а thousandth part of а metre' and 'kilometre' is Greek for 'а thousand metres'.

As for the unit of mass, it was defined as the mass of а cubic centimetre of water at the temperature of 4 degrees (the temperature of its maximum density). As we know, the name of this unit is gramme.

The SI units is derived from the metric system and was internationally accepted in 1960. Besides metre (m), kilogram (kg) and second (s), its basic units are Kelwin (К), ampere (а), mole (mol), and candle (cd). This system was introduced in our country in the 1960s and every day we measure things bу the units from this system.

ВО Аrе most of them

interrelated?

2. How many systems of measurement are widely used nowadays?

3. All the nations of the world use the metric system, don't they?

4. What was used before the metric system? Did the earlier system

have any drawbacks?

5. When was the idea of decimal system realized?

6. What is the main unit of the metric system? How was it measured?

7. Were the units of area and volume defined as well?

8. Do shorter units have Greek or Latin prefixes?

9. What is а unit of mass?

10. Is there а difference between the metric system and the SI system?

11. When was the SI system introduced in the USSR?

12. What synonyms to the phrase 'metric system' can you find in the text?

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Answer 1

1. In physics, there are seven fundamental physical quantities (which are measured in base units, or fundamental physical units): length, mass, time, electric current, temperature, amount of a substance, and luminous intensity.

2. This page explains the two most common systems of measurement: the metric system, used widely in Europe and most of the rest of the world, and the Imperial or British system, a form of which is now chiefly used in the USA.

3. At this time, only three countries—Burma, Liberia, and the US—have not adopted the International System of Units (SI, or metric system) as their official system of weights and measures." We should point out that even these three countries do use elements of the metric system

4. Imperial units

units of measurement of the British Imperial System, the traditional system of weights and measures used officially in Great Britain from 1824 until the adoption of the metric system beginning in 1965. The United States Customary System of weights and measures is derived from the British Imperial System.

5. Decimal fractions were first developed and used by the Chinese in the end of 4th century BCE, and then spread to the Middle East and from there to Europe. The written Chinese decimal fractions were non-positional.

6. In the metric system, the basic unit of length is the meter. A meter is slightly larger than a yardstick, or just over three feet. The basic metric unit of mass is the gram.

9. Student Answers. hazie123 | Student. The unit of mass is the kilogram (kg), but commonly, when we measure something in kilograms, we are measuring the force of gravity on that mass, which should be measured in newtons (N), (a measure of force).

Прости, на 7,8,10,11,12 ответов не знаю :(

Answer 2

1. Physics measures such physical quantities as time, length, mass, density, velocity, area, volume, temperature and energy. Different units of length and mass exist. Nearly all of them are interrelated.

2. Three systems (the British system of unity, the metric system of units and the International system of units (SI))

3. With а few exceptions, all the nations of the world use the metric system.

4. The British foot- pound-second system. It was very complicated and caused serious difficulties in the international trade.

5. Аt the end of the 18th century.

6. Тhe standard of length should bе one ten-millionth part of the distance from the Equator to the North Pole. The two French scientists charged with the task took this distance on а line running through Paris and divided it into 10 000 000 equal parts.

7. Yes. Metre was also used to measure area and volume.

8. 'Millimetre' is Latin for 'а thousandth part of а metre' and 'kilometre' is Greek for 'а thousand metres'.

9. The mass of а cubic centimetre of water at the temperature of 4 degrees.

10. With some differences in details, system elements are the same all over the world.

11. In 1960

12. Decimal system