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)
Xylem tissue that should help you out
Answer:
<h3>The Difference between Afferent and Efferent Neurons :- </h3>
- Neurons that receive information from our sensory organs (e.g. eye, skin) and transmit this input to the central nervous system are called afferent neurons.
- Neurons that send impulses from the central nervous system to your limbs and organs are called efferent neurons.
<h2>Hope this helps you XD !!!</h2>
Carbon dioxide is released during cellular respiration.
Answer:
B. decreases salivation and increases blood pressure
Explanation:
The sympathetic nervous system is part of the autonomous nervous system which controls involuntary responses of the body such as salivation and blood pressure.
The sympathetic nervous system is majorly responsible for body actions that are produced when threat is perceived. It generates responses referred to as the “fight or flight” response. Examples of such responses include, increased breathing, increased high blood pressure, dilation, decreased salivation, etc.
Activation of the sympathetic nervous system would result in rise in the blood pressure as can be witnessed by someone whose body has perceived a threat or reacting to a stressful situation.
The control of salivary production by the sympathetic nervous system leads to the release of noradrenaline which acts on certain receptors that results in decrease in the production of saliva. This is evident in a person that is facing a threat also.
