When was shampoo invented? It was invented in India in about 1500. Our hair gets dirty because we secrete an oil called sebum which protects the structure of the hair and stops it from breaking. However, this oil can build up and other things can stick in it, such as dirt. It also has an […]
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How does a parachute work? A parachute works because of air resistance. If you jump out of an airplane, presuming you are high enough, you are going to accelerate until you reach terminal velocity. Terminal velocity is the maximum speed an object can attain when falling through a fluid. And here is the point that
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How much blood can you lose? Well, obviously all of it. How much blood can you lose and still function? Depending on your body size, from between 15 to 30%. We have approximately 5 liters of blood in our bodies, but that varies by size. An average-sized female of 165 cm will have about 4.3
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Why do we say boycott? The word comes from a British land agent who lived in Ireland. His name was Captain Charles Cunningham Boycott. He was born in England in 1832. He joined the army when his family paid for his commission in 1850. He was not able to join on the strength of his
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When was the Roman forum built? In the 7th century BC. The beginning of the Roman forum is difficult to get a grip on because the Romans liked to embellish the legend of the formation of Rome. The legend is that Rome was founded by the brothers Romulus and Remus in 753 BC. The brothers
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Why is PM 2.5 dangerous? They are particles that are too small for our nose to catch. PM stands for Particle Matter and they are microscopic solid or liquid particles that are small enough and light enough to be suspended in the air. There are many sources of these particles. In some countries, one of
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Why are diamonds so expensive? Because we believe they should be expensive, not because they are rare. We think that diamonds are expensive because they are rare, but they are not as rare as we think. Diamond is a structure made of carbon atoms that are arranged in a crystal structure. Diamond is one of
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Why did the Mayan civilization collapse? Probably because of overpopulation, environmental damage, war, and extended drought. The Mayan people lived in an area that is where southeastern Mexico and northern Central America are today. People started living there in about 8000 BC. By 2000 BC the Maya were settled and farming the land. From about
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When was the penny first used? The first coin to be called a penny was in 790, but the word meant “all money” and not just one coin. There are several currencies across the world that use “penny” for their smallest coin. In the UK there is a one penny coin. In the United States
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How do fossils form? They form when the bones of an animal are turned to mineral. A fossil forms when an animal dies in water or falls into water. This water is more commonly an ocean or a lake because for a fossil to form, the sediment at the bottom of the water has to
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