Physics

A:

Earth is like a giant magnet in several ways. Not only does it have a magnetic north and south pole that act similarly to the poles on bar magnets, but the planet is surrounded by a strong magnetic field, which is electrically charged and able to interact with magnetized matter.

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  • What were the contributions of Archimedes to the field of physics?

    Q: What were the contributions of Archimedes to the field of physics?

    A: The first-century inventor and scientist Archimedes is remembered by physicists as the originator of the principles of mechanics, buoyancy, the lever and the pulley, according to Famousscientists.org. Perhaps his best-known contribution to physics is his discovery of the principle of displacement, which states that objects displace a volume of water equal to their own weight.
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  • How are mass and weight related to each other?

    Q: How are mass and weight related to each other?

    A: Mass and weight are closely related because mass affects the weight of an object experiencing the effects of gravity. Weight is the measure of the force of gravity on an object's mass, while mass is the measure of how much matter there is in an object.
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  • Why does a bouncy ball bounce so high?

    Q: Why does a bouncy ball bounce so high?

    A: Bouncy balls bounce high because the material of the ball is extremely elastic and can convert the kinetic energy from the fall into potential energy and back again with very little loss in momentum. Bouncy balls are used in many physics classrooms because they aptly demonstrate conservation of momentum through a highly elastic collision.
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  • How does gravity affect humans?

    Q: How does gravity affect humans?

    A: Humans evolved with gravity, and gravity affects human physiology and general health. Studies show that weightlessness has a number of negative health effects. Finding ways to mitigate these dangers is essential for long-distance space travel.
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  • What are some good lab experiments that explain centripetal force?

    Q: What are some good lab experiments that explain centripetal force?

    A: One good experiment that explains centripetal force is the spinning penny. A penny is put inside a balloon, and the balloon is filled with air. Then, the balloon is swirled around until the penny rolls around inside of the balloon. The penny continues to spin even after the swirling stops.
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  • How does a fulcrum work?

    Q: How does a fulcrum work?

    A: A fulcrum is the fixed support or pivot point for a lever, which is a simple machine used to overcome resistance. The lever is a stiff rod or bar, and the location of the fulcrum determines the class of the lever. Levers are useful to increase force, increase speed or change direction of a force, according to HowStuffWorks.
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  • What is the difference between kinetic and potential energy?

    Q: What is the difference between kinetic and potential energy?

    A: Kinetic energy is contained in a moving object, while potential energy exists in a stored form. Potential energy can be changed into kinetic energy. Potential energy is ready for release, while kinetic energy is already doing work. The property of a body determines the type of energy it contains.
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  • What is the formula for tension in physics?

    Q: What is the formula for tension in physics?

    A: In physics, the tension on a suspended object said to be equal to the weight of the object plus or minus the mass of the object times the acceleration acting on it. In other words, this is the weight of the object plus or minus the force on it, depending on the direction in which the force is acting.
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  • What is the difference between an atomic bomb and a nuclear bomb?

    Q: What is the difference between an atomic bomb and a nuclear bomb?

    A: Although both atomic and nuclear bombs derive their immense power from reactions that take place in the nucleus of the atom, they do so in different ways. As the terms are most commonly used, an atomic bomb derives its energy from fission, or splitting atoms, while a nuclear device, or "H-bomb," is driven by fusion.
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  • Does light always travel at light speed?

    Q: Does light always travel at light speed?

    A: Light typically travels at 186,000 miles per second, but scientists have found a way to slow it down to 38 miles per hour. A team at the Rowland Institute for Science has found a new state of matter to help slow light down. Sodium atoms were cooled almost to absolute zero, which is 459.67 degrees Fahrenheit below zero. That’s lowest temperature theoretically possible. They then shot a laser through the extremely cold sodium atoms, which acted like “optical molasses” to slow down the beam of light.
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  • What are the Laws of Attraction and Repulsion?

    Q: What are the Laws of Attraction and Repulsion?

    A: The Law of Attraction is the belief that a person's thoughts attract specific things, people and situations into his life. The Law of Repulsion is the belief that the more a person thinks about what he does not want, the more he attracts what he does want. According to SelfGrowth.com, both beliefs support the idea that what a person thinks about, negative or positive, can manifest into reality.
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  • What is the purpose of a windmill?

    Q: What is the purpose of a windmill?

    A: A windmill uses wind power to create rotational energy for the use in mills, pumps and presses. In the Netherlands, where windmills became important for local economies, they were used to make boards, paint, oil, paper and bread.
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  • Why does rubbing your hands together make them warmer?

    Q: Why does rubbing your hands together make them warmer?

    A: Friction causes the hands to warm up when rubbed together. The greater the amount of friction between two objects is, the more heat is generated.
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  • What are examples of noncontact forces?

    Q: What are examples of noncontact forces?

    A: Electricity, gravity and magnetism are all examples of non contact forces. A force is anything that can cause a physical change in an object.
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  • What are the parts and functions of a theodolite?

    Q: What are the parts and functions of a theodolite?

    A: A thedolite is an instrument used to measure horizontal and vertical distances using lenses and lines. They include several components, such as a telescope, a leveling mechanism, a tripod and a compass. Theodolites are used for surveying and construction to obtain precise readings of landforms so construction projects remain level and plumb with the ground.
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  • Why do people need sound?

    Q: Why do people need sound?

    A: The ability to perceive sound is critical for the survival of most species on Earth, including humans. The ability to assess the environment through hearing evolved in a variety of ways in the animal kingdom, and high-functioning animals such as humans adapted the sense of sound as a means to communicate.
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  • Why do ships float on water?

    Q: Why do ships float on water?

    A: Ships float because they displace enough water for the buoyancy force to be greater than the force of gravity acting on the ship. The displaced water attempts to return to its original position, now occupied by the ship, which pushes the ship up. This effect is known as buoyancy force. The strength of the force of gravity pulling down on the ship is affected by its weight. Whichever of these forces is stronger determines if the ship floats or sinks.
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  • What percentage of his brain did Einstein use?

    Q: What percentage of his brain did Einstein use?

    A: Einstein used 100 percent of his brain just as all people do. The contention that humans use only about 10 percent of their total brain capacity is a myth that is sometimes attributed to Einstein.
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  • Can you tell what temperature a fire is by its color?

    Q: Can you tell what temperature a fire is by its color?

    A: The temperature of a flame from a known material can be estimated based on the flame's color. However, flame color is also affected by the material being burnt and differs based on its chemical properties in addition to its temperature.
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  • How does a pulley make work easier?

    Q: How does a pulley make work easier?

    A: A pulley makes work easier by redirecting and amplifying force. It helps reverse the direction of an individual’s lifting force. As a user pulls a rope down, the pulley lifts the weight up. When two ropes and wheels are used, a pulley reduces the effort needed to lift a weight by half.
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  • How is it possible to power a light bulb with a potato?

    Q: How is it possible to power a light bulb with a potato?

    A: A potato helps power a light bulb by acting as both a bridge and a separator for two electrodes made of different metals. The two metals most frequently used are zinc and copper because of their ubiquity and difference in electron affinity. The acid in the potato starts the reaction, and the electrolytes in the potato allow a flow of electrons, an electric current, to flow between the electrodes.
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