Since ancient times, people have harnessed the winds energy. How can we do the same?
Wind is simply air in motion caused by the uneven heating of the earth's surface by the sun. Since the earth's surface is made of very different types of land and water, it absorbs the sun's heat at different rates.
During the day, the air above the land heats up more quickly than the air over water. The warm air over the land expands and rises and the heavier, cooler air rushes in to take its place, creating winds. At night, the winds are reversed because the air cools more rapidly over land than over water.
In the same way, the large atmospheric winds that circle the earth are heated than the land near the North and South Poles.
Over 5,000 years ago, the ancient Egyptians used wind to sail ships on the River Nile. Later, people built windmills to grind wheat and other grains. The earliest known windmills were in Persia, now Iran. They looked like large paddle wheels. Centuries later, the people of Holland improved the basic design of the windmill and gave it propeller-type blades, still made with sails. Holland is famous for its windmills.
American colonists used windmills to grind wheat and corn, to pump water and to cut wood in sawmills. As late as the 1920s, Americans used small windmills to generate electricity in rural areas with no electricity. When power lines began to transport electricity to rural areas in the 1930s, local windmills were hardly used, though they can still be seen on some Western ranches.
The oil shortages of the 1970s changed the world's attitude to energy. Windmills became a good odea again! Today, wind energy is mainly used to generate electricity. Wind is called a renewable energy source because the wind will blow as long as the sun shines.
And here's the link!
We have this beautiful Finding Nemo kite for you to win, courtesy of the Model Shop. It is made of nylon and fiberglass and messures 85 X 72 centimetres
Just tell us the name of one type of wind..
Send your answer, together with your name, age and address, to Junior News by March 9.
Wind is simply air in motion caused by the uneven heating of the earth's surface by the sun. Since the earth's surface is made of very different types of land and water, it absorbs the sun's heat at different rates.
During the day, the air above the land heats up more quickly than the air over water. The warm air over the land expands and rises and the heavier, cooler air rushes in to take its place, creating winds. At night, the winds are reversed because the air cools more rapidly over land than over water.
In the same way, the large atmospheric winds that circle the earth are heated than the land near the North and South Poles.
Over 5,000 years ago, the ancient Egyptians used wind to sail ships on the River Nile. Later, people built windmills to grind wheat and other grains. The earliest known windmills were in Persia, now Iran. They looked like large paddle wheels. Centuries later, the people of Holland improved the basic design of the windmill and gave it propeller-type blades, still made with sails. Holland is famous for its windmills.
American colonists used windmills to grind wheat and corn, to pump water and to cut wood in sawmills. As late as the 1920s, Americans used small windmills to generate electricity in rural areas with no electricity. When power lines began to transport electricity to rural areas in the 1930s, local windmills were hardly used, though they can still be seen on some Western ranches.
The oil shortages of the 1970s changed the world's attitude to energy. Windmills became a good odea again! Today, wind energy is mainly used to generate electricity. Wind is called a renewable energy source because the wind will blow as long as the sun shines.
And here's the link!
We have this beautiful Finding Nemo kite for you to win, courtesy of the Model Shop. It is made of nylon and fiberglass and messures 85 X 72 centimetres
Just tell us the name of one type of wind..
Send your answer, together with your name, age and address, to Junior News by March 9.