Explanation:
Wind energy, or wind power, is created using a wind turbine, a device that channels the power of the wind to generate electricity. The wind blows the blades of the turbine, which are attached to a rotor. The rotor then spins a generator to create electricity . Wind energy is a renewable energy source that is clean and has very few environmental challenges. Wind power actually starts with the Sun. In order for the wind to blow, the Sun first heats up a section of land along with the air above it. That hot air rises since a given volume of hot air is lighter than the same volume of cold air. Cooler air then rushes in to fill the void left by that hot air and voila: a gust of wind. The Office of Energy Efficiency and Renewable Energy describes a wind turbine as “the opposite of a fan.” Simply stated, the turbine takes the energy in that wind and converts it into electricity. So how does it do that? First, the wind applies pressure on the long slender blades, usually 2 or 3 of them, causing them to spin, much like the wind pushes a sailboat along its path through the water. The spinning blades then cause the rotor, or the conical cap on the turbine, and an internal shaft to spin as well at somewhere around 30 – 60 revolutions per minute. The ultimate goal is to spin an assembly of magnets in a generator which will, well, generate voltage in a coil of wire thanks to electromagnetic induction. Generators require faster revolutions, however, so a gear box typically connects this lower speed shaft to a higher speed shaft by increasing the spin rate to around 1000 to 1800 revolutions per minute. These gear boxes are costly as well as heavy, so engineers are looking to design more “direct-drive” generators that can work at the lower speeds.
I think the answer is evolution.
Answer:
d.smooth muscle
Explanation:
Blood vessels contain only smooth muscle cells. These muscle cells reside within the tunica media along with elastic fibers and connective tissue
Answer:
Control group remains unchanged.
Explanation:
For example if you are trying to see if watering plants with Pepsi is better.
Your experiment plant would get watered with Pepsi.
Your control plant would get watered with water. (Control groups serve as a reference to compare in the experiment)
