How do noise cancelling headphones work? They play the sound from around you, but reversed, which cancels out the noise. Sound is a pressure wave that is created by an energy source that makes the molecules of the medium it is travelling through vibrate. Sound can travel through any medium and it travels through some […]
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Do antibiotics kill all of the bacteria in the body? Yes, they do. Antibiotics kill bacteria in the body. They do not work on viruses. We use bacteria when we have an infection and they can be very effective. An infection is caused when we have a wound and bacteria get inside. This is very
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Why are clouds white? Because the water particles in the clouds scatter light equally. When light comes out of the sun, it is white. That is to say, it emits all of the colors of the color spectrum. The sun emits light as radiation and it emits radiation across almost all of the electromagnetic spectrum,
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Why does a cracked whip make a sound? One portion of the whip moves faster than the speed of sound, creating a sonic boom. A sonic boom is created by anything that goes faster than the speed of sound, which is 343 m/s in air. Air behaves in the same way as a fluid, so
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How do weight loss drugs work? They either reduce the appetite, reduce the absorption of nutrients, or increase the amount of fat that the body burns. Obesity is becoming a worldwide problem these days. It used to be only affluent countries that suffered from it, but now there are not many countries that are unaffected.
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Why do poppies make opium? Not all poppies do make opium, but the ones that do, make it to ward off pests. There are 775 different species of poppy, known as the Papaveraceae family. Most of them produce the milky latex that becomes opium in the opium poppy, but only the papaver somniferum is able
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What is truth serum? It is a drug that prevents people from censoring themselves so they reveal the truth. These drugs are usually barbiturates and there is no real proof that they work. People have searched for a drug that can help them get at the truth for thousands of years. The very first type
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What causes turbulence? It happens when an airplane flies through turbulent air (hence the word turbulence) and gets buffeted around. Turbulence can cause a plane to suddenly rise or fall hundreds of meters very quickly. It can also cause a lot of shaking, and it can cause some damage to the plane, but it very
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How does a Maglev train work? They use magnets to move the train forwards and to reduce friction. Maglev is the shortened form of magnetic levitation, and it is a train based on the principle of magnetic attraction and repulsion. We all know that when you have two magnets, the opposite poles attract each other
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Why does ice have so little friction? Because there is a very thin layer of water on top of the ice. Although, the reason for that is not completely understood. If a force is applied to an object it picks up kinetic energy. The kinetic energy is transferred from the energy used to make the
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