Most hydroelectric power plants have a dam and a reservoir. These structures may obstruct fish migration and affect their populations. Operating a hydroelectric power plant may also change the water temperature and the river's flow. These changes may harm native plants and animals in the river and on land. Reservoirs may cover people's homes, important natural areas, agricultural land, and archaeological sites. So building dams can require relocating people. Methane, a strong greenhouse gas, may also form in some reservoirs and be emitted to the atmosphere. Reservoir construction is "drying up" in the United States Gosh, hydroelectric power sounds great -- so why don't we use it to produce all of our power? Mainly because you need lots of water and a lot of land where you can build a dam and reservoir, which all takes a LOT of money, time, and construction. In fact, most of the good spots to locate hydro plants have already been taken. In the early part of the century hydroelectric plants supplied a bit less than one-half of the nation's power, but the number is down to about 10 percent today. The trend for the future will probably be to build small-scale hydro plants that can generate electricity for a single community. As this chart shows, the construction of surface reservoirs has slowed considerably in recent years. In the middle of the 20th Century, when urbanization was occurring at a rapid rate, many reservoirs were constructed to serve peoples' rising demand for water and power. Since Hydroelectric energy is produced by the force of falling water. The capacity to produce this energy is dependent on both the available flow and the height from which it falls. Building up behind a high dam, water accumulates potential energy. This is transformed into mechanical energy when the water rushes down the sluice and strikes the rotary blades of turbine. The turbine's rotation spins electromagnets which generate current in stationary coils of wire. Finally, the current is put through a transformer where the voltage is increased for long distance transmission over power lines.
Hydroelectric-power production in the United States and the world!
(sorry this is the second part)
Answer:
D) A Survey of fellow classmates
Explanation:
This is the correct answer because an informal survey involves various answers that may or may not be accurate. Informal surveys cannot be held as scientific fact and are, therefore, not reliable. A scientific journal is reliable because it most likely includes data from an experiment and/or research of a trusted scientist or group. The results of past experiments are very reliable because these are the results of hard work and thorough planning and research. A scientific discussion with colleagues is not very credible because it involves the sharing of opinionated information, but it is certainly more reliable that the varying answers of school-aged peers.
D. Watershed - a watershed is the area in which runoff, rivers, and streams run into a larger body of water
Answer:
Lipocavitation is a medical
procedure which involves conversion of fat into liquid substances which is then passed out as waste .The procedure includes:
A small amount of ultrasound gel is applied to the area before the Doctor
glides the ultrasound device over the treatment area in all directions.
Cells then release triglycerides and fatty substances which are naturally eliminated through the body lymphatic system.
