Why do we get hot when we exercise? Because heat is a byproduct of the process muscles use to make energy. Let’s look at how we get energy to our muscles. We are unable to make our own energy, we can only convert one energy source into another. We have to eat plants or animals […]
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What is a central bank? It is an institution that manages the currency of a country and controls the supply of money. Nearly every country has a central bank. It is sometimes called a reserve bank. There are nine countries that don’t have one. They are Andorra, Isle of Man, Kiribati, Marshall Islands, Micronesia, Monaco,
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Could a Formula One car drive upside down? Technically yes, but it might need some modifications. Formula One racing cars are some of the fastest cars in the world. The fastest speed ever reached in a Formula One car is 397.36 km/h. This is not as fast as the land speed world record, which is
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Why do some liquids burn and others don’t? Some liquids require less energy to get the chemical reaction over the activation energy barrier. What is fire? Fire is the process of combustion and is a chemical reaction. Fire needs three things to happen: a fuel source, heat, and oxygen. If you remove one of these,
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Could penguins fly in the past? Yes, they could, but millions of years ago. There are many birds that could fly at some point but that have lost the ability. The Galapagos Cormorant is a good example. They are only found on two of the Galapagos islands. They are not originally from the island, so
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How do chemotherapy and radiotherapy work? Chemotherapy works by damaging the DNA inside the nucleus of the cancer cells and stopping them dividing. Radiotherapy works by targeting the cancer directly and damaging its DNA. How does cancer form? As our cells age, they die and new cells replace them. Some cells are replaced more quickly
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Why do dragonflies have four wings? So that they can hover and fly in any direction that they wish. Most insects have two pairs of wings but the second set in some of them have evolved to have a different purpose. Two examples of these are flies and beetles. (I know we are talking about
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How does a pressure cooker work? By using high pressure to raise the boiling point of the water. Pressure cookers were invented in 1679 by a French physicist. He was trying to find a way to cook food faster. Cast iron pressure cookers were made in Germany in 1864. Pressure cookers improved through the early
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How does a refrigerator cool food? By transferring the heat from inside the refrigerator to outside using evaporation. Fresh foods have to be kept cool to make them last longer. As soon as they are opened, or cut, bacteria start to decompose them. When foods decompose, they taste bad, but some bacteria can produce toxins
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Why does metal spark in a microwave oven? The microwave charges one side of the metal positively and one side negatively. This charge can ionize the air, making sparks. First, we need to look at what microwaves are. A microwave is a type of electromagnetic radiation. Electromagnetic radiation is energy that moves in waves and
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