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Which is bigger, a kilometer or a mile?

One kilometer is equal to 0.6214 miles, or one mile is equal to 1.6 kilometers. Kilometers are more popular around the world and are used in all countries that utilize the metric system. It is equal to exactly 1000 meters and is used to denote length and distance. Kilometers and miles are both also utilized on highway and road signs to denote speed whenever they are converted into miles per hour or kilometers per hour.

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What is tension force?

It requires force to put an object under tension, but technically, tension itself is not a force for as long as the situation is stable. Nonetheless, physicists measure the tension in a system in units of force. Once some part of the system begins moving, such as when one end of a rope under tension is released, the potential energy between the molecules of the rope is converted to mechanical energy, and the tension is converted to force. As long as an object under tension is straight, the tension is constant for its entire length.\nA force is any push or pull acting upon an object as a result..

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What do mosses, ferns and liverworts have in common?

Without vascular systems, mosses and liverworts are limited to very damp environments. Ferns, which have roots and vascular systems, can successfully live in drier habitats. Additionally, according to the University of Cincinnati, most ferns have underground stems, which are called rhizomes. Some have vertically growing stems and often go by the common name "tree ferns," based on their growth habit.

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What is the musculoskeletal system?

The musculoskeletal system accounts for around 60 percent of human body mass. These groups of interconnected muscles and bones use up a majority of the body's energy as they work toward providing flexibility and movement. Joints exist between separate bones as ligaments to hold those bones together and ensure that they stay in place. Cartilage keeps bones from rubbing directly against one another.\nCertain types of arthritis result from a wearing away of the cartilage. A lack of cartilage prevents the joint from operating smoothly.\nMuscles keep bones in place, but they also provide movem..

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Why do heat waves occur?

When a ridge of high pressure occurs, the atmosphere inflates at both its lower and upper levels. This inflation prevents other weather systems from moving into the area, and keeps the sky free of clouds. The effects of compression warm and dry the air that sinks down from the upper atmosphere, and the unclouded sunshine ensures that the mass of warm air maintains its heat level. A lack of winds in the upper atmosphere means that it can take a long time for the heat wave to dissipate.\nA 2011 study from the National Oceanic and Atmospheric Administration attributes a large increase in the prob..

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Who proved the Earth was round?

While Pythagoras theorized about a spherical Earth, credit for actually discovering the Earth's shape usually goes to Aristotle. Aristotle made a number of arguments to back up his point, such as how ships appear to sink below the horizon and how constellations move differently when observed from different lands. In addition, Greek philosophers were notorious for assigning discoveries to their earliest thinkers, so it's unclear whether or not Pythagoras really made the discovery he is credited with. In any case, by 250 B.C., the Greeks knew the shape of the Earth and its approximate ..

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How does age affect reflexes?

According to the Merck Manual for Patients and Caregivers, the peripheral nerves conduct impulses more slowly as people get older. This results in slower reflexes, decreased sensation and clumsiness. The layers of tissues surrounding the nerves that make impulse conduction faster tend to degenerate, causing nerve conduction to slow down. As people age, degeneration happens because of decreasing blood flow and overgrowing bones that add pressure on the nerves.\nReflexes also slow with age due to physical changes in the nerve fibers that slow the conduction speed, explains the University of Roch..

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What era are we in?

The extinction of the dinosaurs gave mammals the chance to proliferate and fill most environmental niches. Birds have also thrived in the Cenozoic Era and outnumber mammals two to one. Grass has played an important role in the era and helped to shape the evolution of both mammals and birds. Much of the course of evolution has also been shaped by changing climate. Shifting continents caused changes in ocean currents that resulted in cooling for much of the Cenozoic Era.

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What is mechanical digestion in the stomach?

The tongue, saliva and teeth are crucial structures that allow mechanical digestion to take place. These structures work together to break down solid food so it can be swallowed and travel further through the digestive tract. When food is present in the mouth, a signal is sent to the brain instructing it to secrete more saliva to soften the food. The saliva contains an enzyme that aids in this softening process.\nWhereas the physical softening of the food via the liquid saliva is considered mechanical digestion, the enzymatic process of chemically breaking down the food is chemical digestion. ..

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What did Stephen Hawking discover?

Hawking's black hole theory, in its most simple explanation, says that vacuum fluctuations in black holes causes particle-antiparticle pairs to develop on the edge of the black hole. When this occurs, the draw of the black hole pulls half of that pair in before they can destroy each other, as they are prone to do, causing the remaining part of the pair to emit radiation. From a safe distance this makes it seem as if the black hole is producing particles.

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