A rain in which the precipitation is unusually acidic is called an acid rain. It contains high levels of hydrogen ions. Acid rain is caused when sulphur dioxide and nitrogen dioxide emissions react with water molecules in the air and result in producing acids. These chemicals are produced because of natural sources like decay of vegetation, volcanoes and also from manmade sources like emissions from factories and various types of pollution in the atmosphere. When these gases react with water that is present in the air, form into various acidic compositions. Acid rains are very harmful to the atmosphere. Steel structures like bridges and towers corrode because of the acid. It also results in the peeling of paint from the painted surfaces like buildings. Stone structures get eroded because of the acid in the rain. Acid rain shows adverse effects on human health, forests, sources of fresh water like rivers and streams, and on soil affecting different life forms surviving in these mediums. What Is Smog?The term smog was first coined during the 1950s when it was used to describe a mixture of smoke and fog experienced in London. Major cities along the west coast of America were also experiencing a different type of air pollution.Smog occurs when emissions from industry, motor vehicles, incinerators, open burning and other sources accumulate under certain climatic conditions. There are two types of smog: summer (the type of smog first experienced in America) and winter (the one first noticed in London).Autumn And Winter Smog (Particles)During the cooler months (April to September), Melbourne is more affected by the accumulation of fine particles, which come from motor vehicle emissions, wood smoke, other combustion processes and photochemical processes in the air.Temperature inversions in winter mean that warm air higher in the atmosphere traps pollutants in the layer of cold air closer to the ground. These inversions can last for several days and cause 'scummy' brown hazed horizons until dispersed by wind or rain.The fine particles scatter sunlight, reduce visibility, soil buildings and fabrics and provoke existing respiratory diseases and other health problems.Photochemical Or Summer SmogIn the warmer months (October to March), photochemical smog (summer smog) is caused by the action of sunlight on a mixture of hydrocarbons and oxides of nitrogen. This smog contains secondary pollutants such as ozone, aldehydes and fine particles.
Acid rains are very harmful to the atmosphere. Steel structures like bridges and towers corrode because of the acid. It also results in the peeling of paint from the painted surfaces like buildings. Stone structures get eroded because of the acid in the rain.
Acid rain shows adverse effects on human health, forests, sources of fresh water like rivers and streams, and on soil affecting different life forms surviving in these mediums.
What Is Smog?The term smog was first coined during the 1950s when it was used to describe a mixture of smoke and fog experienced in London. Major cities along the west coast of America were also experiencing a different type of air pollution.Smog occurs when emissions from industry, motor vehicles, incinerators, open burning and other sources accumulate under certain climatic conditions. There are two types of smog: summer (the type of smog first experienced in America) and winter (the one first noticed in London).Autumn And Winter Smog (Particles)During the cooler months (April to September), Melbourne is more affected by the accumulation of fine particles, which come from motor vehicle emissions, wood smoke, other combustion processes and photochemical processes in the air.Temperature inversions in winter mean that warm air higher in the atmosphere traps pollutants in the layer of cold air closer to the ground. These inversions can last for several days and cause 'scummy' brown hazed horizons until dispersed by wind or rain.The fine particles scatter sunlight, reduce visibility, soil buildings and fabrics and provoke existing respiratory diseases and other health problems.Photochemical Or Summer SmogIn the warmer months (October to March), photochemical smog (summer smog) is caused by the action of sunlight on a mixture of hydrocarbons and oxides of nitrogen. This smog contains secondary pollutants such as ozone, aldehydes and fine particles.
Задание 2
1 вариант
2) Уравнения
a)5m+6m=231
5*m+6*m=11*m=231
m=231:11
m=21
б)7x-3x=412
7*x-3*x=4*x=412
x=412:4
x=103
3)Задача
ответ:42кг
Пошаговое объяснения
1) 120:100%=1,2-кг на 1%
2)1,2*65%=78-кг осталось
3)120-78=42-кг вошло в мешок
ответ:42 кг вошло в мешок
4)Примеры
0,81:2,7+4,5*0,12-0,69=4,92
1)0,12*4,5=5,40. 2)0,81:27=0,21 3)5,40+0,21=5,61. 4)5,61-0,69=4,92
5)Задача
Дано: прямоугольник Решение
a-78см. 1)78:3=26-b
b-? (78:3). 2)P=2*(a+b)
Найти:P,S 2)P=2*(78+26)
P=208
S=a*b
S=78*26
S=2.028
ответ:P=208,S=2.028
2-вариант
2) Уравнения
a)4x+7x=132 б)5m-3m=222
11x=132 2m=222
x=132:11 m=222:2
x=12 m=111
3)Задача
ответ:117кг
Пошаговое объяснения
1)120:100%=1,2-кг в 1%
2)1,2*25%=3-кг осталось
3)120-3=117-кг взяли
4)Примеры
0,56:1,4+86*0,15-0,15=12,79
1)0,15*86=12,90
2)0,56:1,4
3)12,90+0,4=12,94
4)12,94-0,15=12,79
5)Задача
Дано: прямоугольник
a-?(18*4)
b-18
Найти:P,S
Решение
18*4
a=72
P=2*(a+b)
P=2*(72+18)
P=180
S=a*b
S=72*18
S=1.296
ответ:P=180,S=1.296
Задание 3
1 вариант
1)а)73.847=74.000
б)65.237=70.230
2)Примеры
(823-754)+258=317
1)823-754=69
2)258+69=317
3) Задача
1)3,6*10 =36 кг яблок в 10 ящ
2)3,2*40=128 кг яблок в 40 ящ
3)36+128=164 кг яблок в 50 ящ
4)10+40=50 ящ привезли всего
5)164:50=3,28 кг яблок в среднем в
1 ящ
4) Уравнения
а)x-1 5/7=2 1/7
x=2 1/7+ 1 5/7
x=3 6/7
б)(12 5/13+y)-9 9/13=7 7/13
12 5/13+y=7 7/13+9 9/13
12 5/13+y=17 3/13
y=17 3/13-12 5/13
y=4 11/13
5)Задача
Дано:
a-?(3,8+0,7)
b-3,8м
c-?в 1,5 раза меньше a
Найти:V
Решение
a)3,8+0,7=3,15м
c)4,5:1,5=3м
V=a*b*c
V=3,8*4,5*3
V=51,м
2-Вариант
14.782=20.002
24.869=30.000
586.382=600.402
2)Примеры
(654+549)-193=1.110
1)654+549=1.303
2)1.303-193=1.110
3)Задача
1)0,9*3=2,7 тонн собранно за 3 дня
2)1,3*2=2,6 тонн собранно за 2 дня
3)2,7+2,6=5,3 тонн всего
4)2+3=5 дней собирали яблоки
5)5,3:5=106 тонн в среднем в 1 день
ответ:106 тонн в среднем в 1 день
4) Уравнения
а)y-2 1/5=5 2/5
y=5 2/5+2 1/5
y=7 3/5
б)(3 9/13+y)-4 9/13=1 7/13
3 9/13+y=1 7/13+4 9/13
3 9/13+y=5 16/13
y=5 16/13-3 9/13
y=2 7/13
5)Задача
Дано
a-5м
b-?(5-1,64)
c-в 1,2 меньше b
Найти:V
Решение
b)5-1,64=3,36м
c)3,36:1,2=2,8
V-a*b*c
V-5*3,36*2,8
V=47,04м