What is a Scramjet? It is an air breathing jet engine that works at supersonic speeds. Right. There are three questions we need to unpack here. How does a jet engine work? How does a ramjet engine work? How does a scramjet engine work? A jet engine has fan turbines at the front of it […]
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Does ABS reduce fatalities in car accidents? Anti-lock braking systems (ABS) have made cars far safer, but they haven’t reduced fatal accidents because of something called risk compensation. Anti-lock braking systems are designed to stop the wheels of a vehicle locking up when the brakes are applied in an emergency. If the wheels on a
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Why are traffic lights red, yellow, and green? Because they cannot be mistaken for each other and we have learned that red means danger and green means go. When they were invented, traffic lights used white to mean “go”, green for “caution” and red for “stop”. The first traffic lights were not made for cars.
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How are tower cranes assembled? By raising themselves up and adding in a piece at a time. There are many different types of cranes, but they are divided into two categories: mobile and fixed. We are looking at the cranes that are used to build skyscrapers today, and they are fixed tower cranes. Any type
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How does a skeleton key work? By removing all of the parts that would get caught on the wards. Skeleton keys are also known as pass keys or master keys. They are called “skeleton keys” because all of the main parts of the key have been stripped off and only the skeleton is left. People
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What are the crown jewels? The crown jewels are a collection of 142 objects, many are used in ceremonies such as the coronation. The Crown Jewels are made up of 13 crowns, 6 swords, 6 sceptres, 16 trumpets, 13 maces, 3 robes, 3 rings, 3 coronets, 2 orbs, 1 spoon and bottle, and lots of
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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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What is the opposite of white? Either black or transparent. Let’s look at what colors are, what white is, and what black and transparent are. Colors appear when an object reflects a certain wavelength of light. Light is energy that is flying through space, called electromagnetic radiation. There are many different types of light and
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How does crop rotation work? By alternating crops to give the soil a rest and to replace nutrients that are removed. People transitioned from a hunter-gatherer culture to an agricultural culture in about 12000 BC. First, they domesticated animals. This happened in different places on Earth within a few thousand years. In about 9500 BC,
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How tall could a skyscraper be? Theoretically 69.1 km tall, but practically, about 2 km. The tallest building in the world at the moment is the Burj Khalifa. It is 830 meters tall. For over 3800 years, the tallest building in the world was the Great Pyramid at Giza. It was 147 meters tall when
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