Sixth grade Science help?
1. Energy can be transferred from one object to another.
2. Energy comes in many different forms, which can generally be divided into Potential or Kinetic energy.
3. Energy can be converted from any one of these forms into any other, and vice versa.
4. Energy is never created or destroyed – this is called the First Law of Thermodynamics.
Atmospheric processes are distinguished in physical and chemical processes and both types may be operating simultaneously in complicated and interdependent ways. The physical processes of transport by atmospheric winds and the formation of clouds and precipitation strongly influence the patterns and rates of acidic deposition, while chemical reactions govern the forms of the compounds deposited.
A major regional or global biotic community, such as a grassland or desert, characterized chiefly by the dominant forms of plant life and the prevailing climate.
I was in sixth grade too ….best of luck 🙂
energy, sources of, origins of the power used for transportation, for heat and light in dwelling and working areas, and for the manufacture of goods of all kinds, among other applications. The development of science and civilization is closely linked to the availability of energy in useful forms. Modern society consumes vast amounts of energy in all forms: light, heat, electrical, mechanical, chemical, and nuclear. The rate at which energy is produced or consumed is called power, although this term is sometimes used in common speech synonymously with energy.
Types of Energy
Chemical and Mechanical Energy
An early source of energy, or prime mover, used by humans was animal power, i.e., the energy obtained from domesticated animals. Later, as civilization developed, wind power was harnessed to drive ships and turn windmills, and streams and rivers were diverted to turn water wheels (see water power). The rotating shaft of a windmill or water wheel could then be used to crush grain, to raise water from a well, or to serve any number of other uses. The motion of the wind and water, as well as the motion of the wheel or shaft, represents a form of mechanical energy. The source of animal power is ultimately the chemical energy contained in foods and released when digested by humans and animals. The chemical energy contained in wood and other combustible fuels has served since the beginning of history as a source of heat for cooking and warmth. At the start of the Industrial Revolution, water power was used to provide energy for factories through systems of belts and pulleys that transmitted the energy to many different machines.
The invention of the steam engine, which converts the chemical energy of fuels into heat energy and the heat into mechanical energy, provided another source of energy. The steam engine is called an external-combustion engine, since fuel is burned outside the engine to create the steam used inside it. During the 19th cent. the internal-combustion engine was developed; a variety of fuels, depending on the type of internal-combustion engine, are burned directly in the engine’s chambers to provide a source of mechanical energy. Both steam engines and internal-combustion engines found application as stationary sources of power for different purposes and as mobile sources for transportation, as in the steamship, the railroad locomotive (both steam and diesel), and the automobile. All these sources of energy ultimately depend on the combustion of fuels for their operation.
Early in the 19th cent. another source of energy was developed that did not necessarily need the combustion of fuels—the electric generator, or dynamo. The generator converts the mechanical energy of a conductor moving in a magnetic field into electrical energy, using the principle of electromagnetic induction. The great advantage of electrical energy, or electric power, as it is commonly called, is that it can be transmitted easily over great distances (see power, electric). As a result, it is the most widely used form of energy in modern civilization; it is readily converted to light, to heat, or, through the electric motor, to mechanical energy again. The large-scale production of electrical energy was made possible by the invention of the turbine, which efficiently converts the straight-line motion of falling water or expanding steam into the rotary motion needed to turn the rotor of a large generator.
The development of nuclear energy made available another source of energy. The heat of a nuclear reactor can be used to produce steam, which then can be directed through a turbine to drive an electric generator, the propellers of a large ship, or some other machine. In 1999, 23% of the electricity generated in the United States derived from nuclear reactors; however, since the 1980s, the construction and application of nuclear reactors in the United States has slowed because of concern about the dangers of the resulting radioactive waste and the possibility of a disastrous nuclear meltdown (see Three Mile Island; Chernobyl).
Biome, also known as life zones, all plants, animals, and other organisms, as well as the physical environment in a particular area. A biome is characterized by its plant life, the types of which are determined by a location’s climatic conditions, latitude, and altitude. For example, northern coniferous forests exist in subarctic portions of North America and Asia, but further north, the conditions are simply too harsh and the season too brief for trees to grow. Instead of trees, the short vegetation of the tundra thrives in these areas. The same phenomenon occurs with altitude, as trees give way to short alpine vegetation in high mountainous regions.
A biome is composed of many ecosystems—smaller communities of plants and animals and their habitats (the physical parts of their environment that affect them). Whereas the boundaries of a biome are determined by climate, the boundaries of ecosystems are physical features, such as ridges or riverbanks, that separate one community from another. The ecosystems of a particular biome tend to have plants with similar growth forms and animals with similar feeding habits.
Major terrestrial biomes include tropical rain forest, northern coniferous forest, tundra, desert, grassland, savanna, and chaparral. Although not necessarily associated with marine environments, the term biome is sometimes used by ecologists to describe marine life zones such as the littoral zone, found in shallow water; the pelagic zone in the open ocean; and the benthic zone on the ocean floor.
The tropical rain forest is the most complex biome in the world. This biome is found at low elevations in the tropics where it is perpetually warm and wet. Rain forests are characterized by a dense tree canopy—tree top branches and leaves that overlap with each other, creating a shaded forest interior. These canopies may reach up to 50 m (160 ft) high. The thick canopy allows little sunlight to penetrate, so rain forest floors have sparse ground cover. The soils are nutrient-poor, and most plants are able to store what few nutrients they can absorb.
The northern coniferous forest, also known as the taiga in Russia, is found in a broad subarctic band across Alaska, Canada, Scandinavia, Russia, and China, where the winters are long and cold. Conifers, such as spruce, larch, and fir, are the dominant plants, but lichens and mosses are abundant too. Muskegs, or bogs, occur throughout the region.
The tundra is the treeless plain that lies north of the northern coniferous forests and on the Antarctic Peninsula in the southern hemisphere. Trees cannot survive in this biome because of the cold temperatures, high winds, and heavy snowfall, as well as the permafrost, a layer of permanently frozen subsoil. Plant life tends to grow low to the ground. In the summer, large numbers of birds migrate to the tundra to feed on insects. Other animals found in this area include reindeer, wolves, fox, voles, and lemmings. A similar biome, called the alpine biome, is found in high mountain areas around the world. Similar harsh conditions cause vegetation to grow low to the ground in alpine meadows.
Desert biomes are characterized by less than 254 mm (10 in) of annual precipitation and high temperatures. To combat this lack of moisture, desert plants have developed water-conserving features, such as leaves that are light-colored, small, thick, or waxy. Animals that live in the desert are often light-colored, blend in well with their surroundings, and are usually more active at night to avoid the blazing heat during the day.
Grassland biomes are found on every continent except Antarctica, accounting for about one quarter of the Earth’s land surface. Typically found on flat or rolling terrain, grasslands tend to occur in the interior of continents where precipitation is lower. Periodic droughts occur in most grasslands, accompanied by searing heat that scorches most vegetation in the area. Grasslands are covered with grasses, sedges, and other low-growing, perennial plants. Drought, fire, and grazing by herbivores, such as bison and deer, restrict tree growth. Most grasslands have been extensively cultivated and are now regions where major crops of wheat, corn, and other grains are grown.
Tropical savannas are expansive grasslands dotted with trees. The world’s largest and best-known savanna is the African savanna, which covers much of the continent south of the Sahara desert. In the African savanna, herds of animals graze on the tall grass, and giraffes browse on the trees. Other tropical savannas are found in South America, India, and Australia.
The chaparral biome is dominated by dense thickets of mostly small-leafed evergreen shrubs. It is characterized by hot, dry summers and cool, wet winters. This biome can be found in the foothills of California and Mediterranean climate regions. Chaparral plants have adapted to the frequent fires that result from lightning and dry conditions.
- Academic Writing
- Case Study
- Critical Thinking
- Education Questions
- Essay Tips
- Essay Writing
- Free Essay Samples
- Free Essay Templates
- Free Essay Topics
- Human Resources
- Problem Solving
- Research Paper
- Review Writing
- Social Issues
- Speech Writing
- Term Paper
- Thesis Writing
- Writing Styles