How is sewage treated? There are several different methods, but sewage generally goes through four steps before the water is safe enough to drink. Sewage isn’t only the wastewater from our toilets. It can be other wastewater from our houses, containing soaps and household products. It can also be industrial wastewater, containing chemicals and other […]
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How does a speedometer work? By translating the speed of the wheel’s rotation into a magnetic field. These days, electronic speedometers are becoming more common, but mechanical ones are still the norm. Let’s look at mechanical ones first. The mechanical speedometer has a dial that sits in the dashboard and miles or kilometers around the
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Why is a strike called a “strike”? Because sailors in 1768 struck their ships. To strike a ship means to take off its topsail, making the ship incapable of movement. The word “stricken” comes from the same place. As in, the ship was stricken on the rocks. On a ship, the command to take down
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What is an anchorite? An anchorite or an anchoress were people who were walled into a small cell built into a church so that they could carry out a life of prayer and religious contemplation. Anchorites were men and anchoresses were women. The great majority of anchorites were actually women. Studies of the archives have
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How does a naval mine work? There are several different kinds of mine that are intended for different targets and there are several different detonation mechanisms depending on the age of the mine and the cost. Naval mines have existed since explosives were discovered. The first naval mines were used in China in the 14th
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Why does the USA use the dollar? Because, in the early days of the American colonies, the Spanish dollar was more prevalent than the British pound. There are twenty countries around the world that have a dollar as their currency. The symbol for the majority of them is the $ sign with possibly letters before
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What is the difference between a petrol engine and a diesel engine? They use different fuel, they ignite the fuel in a different way, and a diesel engine is more efficient than a petrol engine. Diesel and petrol are both made from crude oil. Crude oil is the petroleum that is taken out of the
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Why are UK public schools actually private schools? They were not attached to a church and were open to the fee-paying public. They are technically not for profit charities. In most countries, public schools are run by the government and private schools are run by private institutions. In the UK, public schools are a different
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How is Easter calculated? Easter is the first Sunday after the full Moon that occurs on or after the spring equinox. When to celebrate Easter is a problem that has taxed the church for centuries. The date of Easter is very important for the Christian church because the whole religion revolves around the birth and
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What happened to biplanes and triplanes? They produce too much drag, which means they can’t fly fast enough and they use a lot more fuel. The first planes built were biplanes. The first heavier-than-air plane was a triplane. Sir George Cayley built a glider with three wings in 1848. He managed to convince a local
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