Answer:
Explanation:
Given that,
Frequency of a radio antenna is 1 MHz
Power, P = 21 kW
We need to find the the waves intensity 25 km from the antenna
. The object emits intenisty evenly in all direction. It can be given by :
So, the wave intensity 25 km from the antenna is 
.
Answer:
Granite is durable, as it is hard and tough.
Gneiss has resistance to pressure and mechanical impacts
Explanation:
Granite is an igneous rock. It is mostly used in building works and construction because they are very durable. They are hard and tough and they have no internal structures.
Gneiss is used for flooring, ornamental stone, tombstones because of the fact that it shows resistances to pressure and also mechanical impacts.
<u>how they are formed in nature:</u>
In nature, granite is formed from the cooling down of hot molten magma and it's solidification before it reaches the surface of the earth.
In nature, gneiss is as a result of igneous rock or sedimentary rocks metamorphosing. Gneiss and granite are kind of similar. When subjected to great heat, granite becomes gneiss
When something is heated or cooled, its length changes by an amount proportional to the original length and the change in temperature: linear expansion : ΔL=αL0ΔT (α is the coefficient of linear expansion) The coefficient of linear expansion depends only on the material an object is made from.
Thanku have a great day ✨❤️
Answer:
The opponent-process theory
Explanation:
The opponent process theory is based on the human visual system and according to the theory the interpretation of the color is done by the photo-receptors rods and cones in the human eye.
This theory states that the perception of color is governed by the two opponent system which includes - a red-green, a blue-yellow and a black-white mechanism.
Any activity in one of these restricts the activity in the other.
Answer:
substances will move faster and become warm to the touch.
Explanation:
when the radiation from the sun comes down and hits substances, the substances absorbs the radiation making them warm. the absorbed energy is transformed into heat energy. this heat energy plays an important role in regulating the temperature of the Earths crust, surface waters, and low atmosphere.
