{
  "Calyx_5": [
    {
    "SST": [
       
        {
          
          "chapter1": {
            "author": "",
            "chapter_title": "Major Landforms",
            "type": "",
            "content": "Ryan’s Social Studies class begins with the chapter on different landforms of the Earth.Mountains spread over 20 per cent of the Earth’s total land area. Their height rises more than 900 metres above the average sea level. The tip of the mountain is known as its peak or summit. These landforms have different heights and shapes, basis their age. Young mountains, such as the Himalayas and the Alps, are tall and have conical or pointed peaks. Old mountains, such as the Appalachians and the Aravallis, are low and have rounded peaks. Mountains protect us from extreme hot and cold winds, by acting as a physical wall. They are home to many rivers that provide water for irrigation. Various mountains are rich in pasture lands, forests and minerals. Unlike plains, mountains have sharp slopes and thin soil cover. Thus, it is difficult to grow crops on such terrains. Mountainous areas have less population due to unsuitable climate and lack of flat terrain that makes transportation difficult. Tablelands or plateaus are highlands with a flat top and steep slopes rising rapidly from the surrounding land. Plateaus have many rivers and streams. The climate here is cold due to the high altitude. The growing season is short. India’s Deccan Plateau is vast. The Tibetan Plateau in Asia is the highest and largest plateau of the world. The Bolivian Plateau (South America) and Colorado Plateau (North America) are other examples of vast-spread plateaus. A majority of the plateaus lie in dry regions, on the leeward side of the mountains. Canyons are a common feature in various plateaus. Plateaus comprise grasslands. Cattle and sheep are reared here. Many tablelands have rich deposits of minerals. Plains are low-lying and flat lands. The terrain can be level or slightly hilly. The slope of a plain is gentle. Plains, such as the northern plains of India, are formed by the deposition of silt and sand from rivers. More people live on plains, as opposed to mountains and tablelands. Many old civilizations emerged along the rivers on lowlands. This is because plains have fertile soil. They are suitable for growing crops. Many big cities and towns are situated in the plains. Owing to their flat and level terrain, it is easier to construct airfields, canals, roads and railways on plains. Deserts are dry landforms. They receive little or no rainfall. Some examples are the Sahara and the Kalahari Deserts in Africa and the Arabian Desert in Asia, among others. Deserts are characterised by hot days, cold nights and recurrent dust storms. Sand dunes are also found in deserts. Very few plants or crops grow here due to little or no rainfall. A majority of deserts are located towards the western side of continents and on the leeward side (the side of a mountain that is sheltered from winds) of mountains. There are natural channels on the Earth that carry rainwater or water from melted snow and ice from mountains to plains, lakes and seas. These channels are called rivers. They begin as streams and come together to form a river. A river goes through three courses from its location of origin to its mouth. A majority of rivers originate in the mountains. At this stage, its speed is very high. Rivers cut deep and narrow channels in the mountains. Canyons, waterfalls and rapids are some features of the upper course. This stage begins when the river leaves the mountains and enters the plains. Here, the speed of the river decreases and it forms loops called meanders. At this stage, the river joins a larger water body, such as a sea or a lake. Here, its speed is very slow. The river creates a delta by depositing the silt it carries near the mouth. A delta is a land, triangular in shape."

          }
        },
        {
          "chapter2": {
            "author": "",
            "chapter_title": "Parallels and Meridians",
            "type": "",
            "content": "The Earth is spherical in shape. Spherical objects do not have corners or sides. Then, how do we locate places on the Earth? For this purpose, some imaginary lines are used as reference. These are known as parallels and meridians. The Earth rotates on its own axis. It is an imaginary line drawn through the middle of the Earth. Its end points are marked as poles. They are used as fixed points. At the top is the North Pole. The one at the base is the South Pole. Parallels or lines of latitude are lines of reference drawn on a globe. These are a set of circles, running from east to west. The Equator is the longest parallel. It divides the Earth into two equal halves, the Northern Hemisphere (northern half) and the Southern Hemisphere (southern half). Parallels help locate places in the north or south directions. Parallels are complete circles. As we move towards the poles and away from the Equator, the length of the parallels decreases. Parallels lie at an equal distance from one another. They neither cross nor touch each other. The Equator is marked as 0° latitude. We take it as the starting point to number the parallels. From there, the other parallels are marked from 0° to 90°. Thus, each parallel has a value. Moreover, they are also marked as N (North) or S (South), depending on their location. Lines of latitude are marked at 1° gap. In total, there are 181 parallels, including the Equator. The important parallels are the Equator (0°), the North Pole (90° N), the South Pole (90° S), the Tropic of Cancer (23½° N), the Tropic of Capricorn (23½° S), the Arctic Circle (66½° N) and the Antarctic Circle (66½° S). The Arctic and the Antarctic Circles are also called polar circles. Refer to Figure 2.1 to locate the major parallels. Meridians or lines of longitude locate places in the east or west directions. They are drawn from pole to pole and run from north to south. Refer to Figure 2.2 to see the depiction of meridians. All meridians have the same length. Towards the Equator, meridians have the maximum distance between them. This distance decreases as we move away from the Equator and towards the poles. The meridians meet with the parallels at right angles (90°). All the meridians meet at the poles. In 1884, Greenwich, a place near London, was affixed as the starting point for numbering the meridians. Prime Meridian is a line of longitude that passes through Greenwich. It is marked as 0°. Any meridian of a place is measured east or west of the Prime Meridian. Meridians are marked at a gap of 1° each. The Prime Meridian divides the Earth into two hemispheres, namely, the Eastern Hemisphere and the Western Hemisphere. The Earth has 180 meridians each, towards the east and the west of the Prime Meridian. The longitude of 180° E and 180° W is the same line. If we travel halfway around the world from the Prime Meridian, we get the 180° longitude. Thus, there are 360 lines of longitude in total. The International Date Line is marked as 180°. You may locate a place on the globe by knowing the value of its parallel and meridian. The point where both intersect will give you the location of the place. This intersection point is known as a grid. Meridians help us calculate time. The time difference between two longitudes is 4 minutes. Let us understand how it is calculated. We know that the Earth takes 24 hours to complete one rotation. Also, 1 hour = 60 min. Thus, the Earth takes 24 × 60 = 1440 minutes for one complete rotation. Again, we know that there is a total of 360 meridians. So, if we divide the total number of minutes by the total number of meridians, we will get the time difference between two longitudes. That is, 1440 ÷ 360 = 4 Furthermore, the places on the Eastern Hemisphere are a day ahead of those that lie in the Western Hemisphere. The International Date Line splits the Earth to give us two different dates on a calendar. For instance, India, a country on the Eastern Hemisphere, is 12 hours ahead of USA, a country in the Western Hemisphere."

          }
        }
      ]
    }
  ]
}