АвтомобилиАстрономияБиологияГеографияДом и садДругие языкиДругоеИнформатикаИсторияКультураЛитератураЛогикаМатематикаМедицинаМеталлургияМеханикаОбразованиеОхрана трудаПедагогикаПолитикаПравоПсихологияРелигияРиторикаСоциологияСпортСтроительствоТехнологияТуризмФизикаФилософияФинансыХимияЧерчениеЭкологияЭкономикаЭлектроника
Energy. Forms of Energy.
Environmental Pollution. Air Pollution.
There are several kinds of environmental pollution: air pollution, water pollution, soil pollution, and pollution caused by solid wastes, noise, and radiation.
Air pollution is occurs results from pouring hundreds of millions of tons of gases the atmosphere. Air pollutants can also damage the eartn `s upper atmosphere. Most air pollution results from burning of petrol and coal.
Water pollution reduces the amount of pure, fresh water that is needed for drinking and cleaning, swimming and fishing.
Soil pollution damages the thin layer of fertile soil that is essential for growing food. Through bad treatment people greatly destroy soil.
Solid wastes are probably the most visible forms of pollution. Examples of solid wastes include types, refrigerators, cans and other packaging materials; and scraps of metal, paper, and plastic. Dumps ruin the attractiveness of the nearest areas and provide homes for rats and cockroaches
Radiation is an invisible pollutant that can be highly dangerous. Nuclear radiation comes from radioactive substances, including waste from nuclear weapons testing and from nuclear power plants.
All types of pollution damage life on Earth
Energy. Forms of Energy.
Energy is the capacity of a physical system to perform work. Energy exists in several forms such as kinetic or mechanical energy, potential energy.
According to the law of conservation of energy, the total energy of a system remains constant, though energy may transform into another form.
Potential and kinetic energies.
Potential energy is stored energy and the energy of position — gravitational energy. There are several forms of potential energy.
Chemical Energy is energy stored in the bonds of atoms and molecules. Batteries, biomass, petroleum, natural gas, and coal are examples of stored chemical energy. Chemical energy is converted to thermal energy when we burn wood in a fireplace or burn gasoline in a car's engine.
Mechanical Energy is energy stored in objects by tension. Compressed springs and stretched rubber bands are examples of stored mechanical energy.
Nuclear Energy is energy stored in the nucleus of an atom — the energy that holds the nucleus together. Very large amounts of energy can be released when the nuclei are combined or split apart. Nuclear power plants split the nuclei of uranium atoms in a process called fission. The sun combines the nuclei of hydrogen atoms in a process called fusion.
Gravitational Energy is energy stored in an object's height. The higher and heavier the object, the more gravitational energy is stored. When you ride a bicycle down a steep hill and pick up speed, the gravitational energy is being converted to motion energy. Hydropower is another example of gravitational energy, where the dam "piles" up water from a river into a reservoir.
Kinetic energy is motion — of waves, electrons, atoms, molecules, substances, and objects.
Radiant Energy is electromagnetic energy that travels in transverse waves. Radiant energy includes visible light, x-rays, gamma rays and radio waves. Light is one type of radiant energy. Sunshine is radiant energy, which provides the fuel and warmth that make life on Earth possible.
Thermal Energy, or heat, is the vibration and movement of the atoms and molecules within substances. As an object is heated up, its atoms and molecules move and collide faster. Geothermal energy is the thermal energy in the Earth.
Motion Energy is energy stored in the movement of objects. The faster they move, the more energy is stored. It takes energy to get an object moving, and energy is released when an object slows down. Wind is an example of motion energy. A dramatic example of motion is a car crash, when the car comes to a total stop and releases all its motion energy at once in an uncontrolled instant.
Sound is the movement of energy through substances in longitudinal (compression/rarefaction) waves. Sound is produced when a force causes an object or substance to vibrate — the energy is transferred through the substance in a wave. Typically, the energy in sound is far less than other forms of energy.
Electrical Energy is delivered by tiny charged particles called electrons, typically moving through a wire. Lightning is an example of electrical energy in nature, so powerful that it is not confined to a wire.
3.Traditional Energy Sources.
The energy sources that cannot be recreated and which go on depleting as we use them are non-renewable energy sources. At present most of the needs of the world are fulfilled by non-renewable sources of energy. The most extensively used non-renewable energy sources is a petroleum,natural gas,coal,propane, nuclear. The fossil fuels are formed from the dead bodies of the plants and animals buried below the deep layers of earth’s core since millions of years ago.
Petroleum or crude oil is the only energy source that occurs naturally in liquid form. It was made by marine animals and plants dying millions of years ago and being covered by mud over all that time. Heat and pressure turned the remains into oil.
Natural gas, mostly methane, is found in the same places as oil and coal. It is a by-product of the compression process fossil plants and animals go through. There are also machines today that can turn plant matter and animal waste into natural gas.
Coal is the most abundant fossil fuel in the United States. It was created by the plants that died in swamps millions of years ago that were covered by dirt and water, and slowly compressed over time.
Propane is another by-product of the oil drilling process. It is captured in gas form and turned into a liquid for consumer and commercial use.
Most nuclear energy is supplied by uranium. Uranium is a metal found throughout the world. Nuclear plants use a specific type of uranium for the fission process, however. U-235 is a rare type of uranium which must be extracted. Most uranium for nuclear energy is mined in the western United States.
Дата добавления: 2015-09-14; просмотров: 10; Нарушение авторских прав