Составить план текста Physics measures such physical чшntitics as time, length, mass,
density, velocity, area, volume, tempcrature and cnergy. Different units of
length and mass exist. Nearly all ofthem are interrelated. Nowadays, three
main systems of measurement are widely used: the British system ofunity,
the metric system ofunits and the Intemational system of units (SI).
With а few exceptions, all the nations ofthe world use the metric system.
It is so easy that anyone who knows arithmetic can leam 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 intemationa1 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
Ьу ten. Therefore, the conversion to а higher quantity is done Ьу moving the
decimal point to the right to the required number of p1aces, and vice versa.
The idea of decimal system was realised only at the end of the 18th
century. In 1791, the French Academy of Science decided that the standard of length should Ье one ten-rnillionth 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 cublc metre appeared.
The main advantage of the system is that for shorter measurements the
metre is divided Ьу ten, so а decima1 system was used. Shorter units had
Latin preftxes and longer ones - Greek preftxes. 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 cublc centimetre of water at the temperature of 4 ·с (the temperature of its maximum
density). As we know, the name of this unit is gramme.
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The SI units is derived from the metric system and was intemationally
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 Ьу the units from this system.
Velikiy Novgorod — one of the oldest and most famous cities of Russia (in 2009 officially said 1150 years). The location of the calling Chronicles, Rurik and origin of the Russian statehood. In the Middle ages — the center of Novgorod Russia and then the Novgorod land centre in the old Russian and Russian States. In 1136 it became the first free-style Republic on the territory of the feudal Russia (from now on, when after the battle at the mountain Ganoi Prince Vsevolod I of Kiev fled from the battlefield, the powers of the Prince of Novgorod was severely limited). For a period of time beginning in 1136 and ending the year 1478, when Novgorod lost (as a result of the victory of Prince of Moscow Ivan III the Great over the people of Novgorod to the Moscow-Novgorod war, 1477-1478) political autonomy, in relation to the Novgorod land, it is customary to apply the term "Novgorod Republic" (government last used the designation of Lord Novgorod the Great).
Novgorod was not subjected to the Mongol invasion; although he paid tribute to the Horde, but retained the unique monuments of old Russian architecture of pre-Mongol period, and was the only one of ancient Russian cities, escaped the decline and fragmentation in the XI—XII centuries.
The population of Veliky Novgorod — 221 954[3] people (2015); 90-e a place in Russia, it's about a third of residents of the area 90.08 km2.
I want to tell you how I spent my summer.
I spent the summer very well. All summer was dry and sunny weather. My friends and I a lot of swimming and sunbathing on the river. In the evening we played football. In July, I went with my parents to the Crimea. We were traveling through the mountains. We saw many new birds and animals.
In August, I was visiting my grandmother in the garden. I helped her harvest. This year has grown a lot of fruits and berries. My grandmother was making delicious jam. The summer was great!
And how did you spend your summer?
Your friend,
Alex