Answer:
D) diffraction
Explanation:
Corona is an optical phenomenon produced by the diffraction of sunlight or moonlight, as light moves through water droplets in the atmosphere.
This phenomenon produces one or more diffuse concentric rings of light around the Sun or Moon, usually seen as colored circles.
Therefore, the explanation for these phenomena of colored concentric circles, sometimes seen with the Sun or the Moon involves diffraction.
The average density of the material from which the coin is made is 9.67 g/cm³.
<h3>Volume of the coin</h3>
The volume of the coin at the given diameter is calculated as follows;
V = Ah
where;
- A is area of the coin
- h is the thickness of the coin
V = πd²/4 x h
V = π(2.8)²/4 x (0.21 cm)
V = 1.293 cm³
<h3>average density of the coin</h3>
The average density of the material from which the coin is made is calculated as follows;
density = mass/volume
density = 12.5 g / (1.293 cm³)
density = 9.67 g/cm³
Thus, the average density of the material from which the coin is made is 9.67 g/cm³.
Learn more about average density here: brainly.com/question/1354972
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Decreases, stays the same, increases.
The volume decreases because as air is cooled, the individual molecules collectively possess less kinetic energy and the distances between them decrease, thus leading to a decrease in the volume they occupy at a certain pressure (please note that my answer only holds under constant pressure; air, as a gas, doesn't actually have a definite volume).
The mass stays the same because physical processes do not create or destroy matter. The law of conservation of mass is obeyed. You're only cooling the air, not adding more air molecules.
The density decreases because as the volume decreases and mass stays the same, you have the same mass occupying a smaller volume. Density is mass divided by volume, so as mass is held constant and volume decreases, density increases.
I think it is A........................................
It’s FF= μ•Fn
Ff stands for friction force
The weird symbol is your coefficient of friction which has no units
Fn stands for normal force
