Questions with a must KNOW Answer!!
Q: How tall is the leaning tower of Pisa?
A: It is built of white marble. The walls are 4 meter thick at its base. It has 8 stories and is 54.5 meters high (which in our country would be about the height of a 15-story building.)
The stairs, consisting of three hundred steps lead to the top. The tower "leans" by 5 meters. If you stand on the top and throw a stone, it would hit 5 meters away from the wall at the bottom of the tower. It leaned when it was built. It was intended as a bell-tower for the cathedral, which is nearby. (Begun on 1174 and finished in 1350) The foundation was laid in sand, and this may be why it "leans". It begun to lean when only three of its stories were made. In the last hundred years it has leaned 0.3 meters more. Engineers call it "the falling tower" because they believe it will TOPPLE over.
Q: Are the Continents moving?
A:the German scientist, Alfred Wegener discovered the theory that the continents are moving, in 1912. Wegener thought all the continents were first big (singles) mass the it moved as present. Some scientists didn't agree and suggested other ways. Some were:
The heat from the interior of the earth creates convection currents that make the continents move. Others thought that the ocean floor was being pulled apart by currents in the mantle of the earth's crust. So there is no agreement on the subject.
Q: Why is the White House white?
A: The white wasn't always white, nor was it always called the White House. But it has been the official residence of the president of the United States. It was designed by Irish-born architect James Hoban and was laid on October 13, 1792. The house was actually built of the gray sandstone. During the war 1812, British troops invaded Washington and burned the structure. Under Hoban's directions the gray sandstone was painted white to cover the smoke. So came to be know as White House, but it was not an official name until Theodore Roosevelt adopted it.
It's interesting to know how many rooms in the White House are known by their color. The Blue Room, which is oval in shape, is the reception room for the president and his wife. The red room is furnished with objects of the Empire period. The Green Room is furnished with objects going back to the days of John Adams and Thomas Jefferson. There is a Rose Guest Room upstairs where the president and his family live.
Q: Why is it cooler on the top of a mountain?
A:Our atmosphere is divided into main layers, which are the troposphere, the stratosphere and ionosphere. The upper boundary is about 11,000 meters above the surface in temperate latitudes. The higher we go the temperature drops by 2 degrees centigrade. So when we go up a mountain we are going in troposphere. At the top of a mountain the temperature is nearly 60 degrees below zero.
The main reason is that the sun heats the earth and the earth gives off heat that warms the air. The sun doesn't warm the atmosphere directly.
Q: Why does our temperature rise when you're sick?
A:The first thing our mom or a doctor will do, when we are sick, is take our temperature. Our body has an average temperature of 37 degrees. The strange thing is that we still don't know what fever is. But we do know that fever actually helps us fight off sickness.
Here's why: Fever makes the vital processes and organs in the body, work faster. The body produces more hormones, enzymes, and blood cells. The hormones and enzymes, which are useful chemicals in our body, work harder. Our blood cells destroy harmful germs better. Our blood circulates faster, we breathe faster and we thus get rid of wastes and poisons in our system better.
When we have fever for 24 hours, you destroy protein in your body. And since protein is necessary for life, fever is an "expensive" way to fight off disease.
Q: Why do Golf Balls have "Holes"?
A:To start with, those are not "holes" in golf balls but they are small indentations called dimples. Early in the history of golf, the balls were made of heavy leather, stuffed with feathers. Today the ball is made by winding strip rubber tightly around a core and covering it with a hard, rubberlike material.
Since one of the objectives of the game is to be able to hit the ball a long distance, and do it accurately, the cover of the ball is usually marked with the small indentations. It has been found that these indentations allow the ball to fly straight when struck properly. It also lessons the wind resistance and thus gives greater power.
Q: What is a laser beam?
A:The word "laser" is formed from the first letters of a long scientific word. The first two letters stand for "light amplification". The s, e, and r stand for "stimulated emission of radiation." Laser beams can travel long distances through space without spreading out. It is becoming an important means of communication in the space age. The distance from the crest of one wave of light to the next crest is called wavelength.
A laser beam is made up of rays that are all exactly the same wavelength and also all rays move in one direction. When light rays are in step like this, they strengthen one another. That is why laser beam is so powerful
Q: Who invented the Traffic Signals?
A:Julias Caesar was probably the first government official to order a traffic control regulations. He passed the law that no woman was to drive a chariot in Rome. It was not until the early 1920's that automobile traffic lights were first used. In 1927 two men patented "traffic-actuated" controllers. These lights were designed to adjust to the amount of traffic passing through an intersection. One of these lights, invented by Harry Haugh of Yale University, was first installed in New Havens, in April 1928.
This device worked by means of pressure detectors in the road pavement. A car passing over a detector signaled the "call box" on the light pole, which caused the light to turn green for the approaching vehicle. It is also widely used today. Charles Alder also invented a traffic light that used a microphone to activate the call box. When the motorist blew his horn, the sound was transmitted from the microphone to the call box, which caused the light to change.