Có 19+ tài liệu thuộc chủ đề "Practice"
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Practice I. Em hãy tìm từ mà phần gạch chân có cách phát âm khác các từ còn lại. (1đ) 1. A. worked B. played C. studied D. lived 2. A. safe B. nature C. mall D. face 3. A. proud B. resource C. scout D. sound 4. A. cheap B. match C. chore D. […]
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Science and fields of science. is the term which is used, in its broadest meaning to denote systematized knowledge in any field, but applied usually to the organization of objectively verifiable sense experience. The pursuit of knowledge in this context is known as pure science, to distinguish it from applied science, which is the search for practical uses of scientific...
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Physics and scopes of Physics. Physics is the major science dealing with the fundamental constituents of the universe, the forces they exert on one another, and the results produced by these forces. Sometimes in modern physics a more sophisticated approach is taken that incorporates elements of the three areas listed above. it relates to the laws of symmetry and conservation,...
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Chemical reactions occur continuously in the atmosphere, in factories, in vehicles, in the environment, and in our bodies. MATTER AND MEASUREMENT. Matter and Measurement. Matter, in science, is the general term applied to anything that has the property of occupying space and the attributes of gravity and inertia. In philosophy, matter has been generally regarded as the raw material of...
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International System of Units. International system of unit is the name adopted by the Eleventh General Conference on Weights and Measures, held in Paris in 1960, for a universal, unified, self-consistent system of measurement units based on the MKS (meter-kilogram-second) system. The Metric Conversion Act of 1975 commits the United States to the increasing use of, and voluntary conversion to,...
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ELEMENTARY PARTICLES. Elementary Particles. In physics, particles that cannot be broken down into any other particles are called elementary particles. The term elementary particles also is used more loosely to include some subatomic particles that are composed of other particles. Particles that cannot be broken further are sometimes called fundamental particles to avoid confusion. These fundamental particles provide the basic...
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Besides the blowing dust and the heavenly bodies, little else moves on the Martian landscape. On earth we see liquids flowing, people moving, and the wind stirring the leaves of trees. Although we can not see them, we know that the very atoms and molecules of matter are continuously in motion. It is one thing to recognize motion but another...
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This hypothesis provides a general model for the mechanics of gravitation. The team of medieval physicists stepped out of the time machine and began to examine the strange, new device fastened to the window. I merely wish to emphasize mankind's present level of ignorance of the mechanics of our universe. The invisible molecules that make up air constantly bombard the...
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Spectral analysis. This may have given you the impression that only the spectrum of one of the elements in a compound can be observed. It is true that the flame of your alcohol burner is hot enough to produce the spectra of sodium, lithium, calcium, copper, and a few other elements, but that is not hot enough to produce the...
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Perhaps nothing is so ingrained in our senses as the perpetual pulling of the earth on our surroundings. Your weight is the pull of earth’s gravity on your body. Likewise, the weight of your car is the force of the earth’s attraction for it. Because of the Earth’s stronger gravitational attraction, these rocks weigh more on Earth, about six times...
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Once the motion stops, the friction stops, and it can not restore the kinetic energy of the keys as gravity is able to do.. Frictional forces don’t store energy in the form of potential energy. The keys skid across the surface of the floor, scraping and catching. The affected surface molecules of the keys and the floor are pushed through...
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It's like a telephone exchange - nerves carry messages in and out from various parts of the body. One of the experiments that convinced nineteenth- century physicists that light is a wave was Young’s double-slit experiment. At any point on the screen, light waves are arriving from each slit. Exercise 2: Find the words/ phrases in the reading text with...
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Earth’s magnetic field. Scientists still do not know exactly what causes the earth’s magnetic field. In the 16th century, it was believed that a mountain of magnetite (a magnetic mineral) was located at the North Pole and that this mountain caused the earth’s magnetic field. Current theories hold that the earth’s magnetic field is created by currents within the liquid...
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The strength and rigidity of the solid, then depends to some degree on how strong the bonds are between those atoms or molecules. When there is an order, that is a pattern in the placement of the molecules or atoms that repeats throughout the solid, it is called crystalline. Ice cream that is frozen too slowly is very grainy in...
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This common characteristic, that an electrical apparatus must have two wires connecting it to a source of electricity, gave the rise in the eighteenth century to the idea that when an electrical device is working, something is moving through it. When you pull out a plug, turn off a switch, or disconnect a battery, the flow of electric charge stops...
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One answer lies in the origins of the nuclei we are considering. This uranium has been part of the Earth since it was formed, 4500 million years ago.. But where did they come from in the first place? It is believed that heavy elements (such as uranium) were formed in a supernova. At some time in the distance past, an...
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1.1 Complete the sentences with one of the following verbs in the correct form:. do you do. in the east. Do you listen 6. (what/do in the evenings. in the middle of walking home. A: What's in the newspaper today?. You ask: (you/sit in the sun?) Have you been sitting in the sun?. We are interested in the activity. It's...
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Use of Apparatus for the Determination of Length Change of Hardened Cement Paste, Mortar, and Concrete 1. the number immediately following the designation indicates the year of original adoption or, in the case of revision, the year of last revision. 1.1 This practice covers the requirements for the apparatus and equipment used to prepare specimens for the determination of length...
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A weight W is suspended from the end of the string.. The block………the string.. The string………the pulley.. The string……….the weight.. That force is the gravitational pull of the sun. Weight (n): the force of the Earth’s gravitational attraction for an object. It was ignored by most of the scientific community. ………….The medieval physicists had never known of the force of...