The total power emitted by an object via radiation is:
where:
A is the surface of the object (in our problem,
is the emissivity of the object (in our problem,
)
is the Stefan-Boltzmann constant
T is the absolute temperature of the object, which in our case is
Substituting these values, we find the power emitted by radiation:
So, the correct answer is D.
<span>the arrangement of the outer planets is
</span>1. Mercury
<span>2. Venus </span>
<span>3. Earth </span>
<span>4. Mars </span>
<span>5. Jupiter </span>
<span>6. Saturn </span>
<span>7. Uranus </span>
8. Neptune
the inner most of the outer plannets is jupitor it is followed by saturn uranus and neptune
Answer:
Solids
:A solid has a definite shape and volume because the molecules that make up the solid are packed closely together and move slowly. Solids are often crystalline; examples of crystalline solids include table salt, sugar, diamonds, and many other minerals. Solids are sometimes formed when liquids or gases are cooled; ice is an example of a cooled liquid which has become solid. Other examples of solids include wood, metal, and rock at room temperature. Liquids
: A liquid has a definite volume but takes the shape of its container. Examples of liquids include water and oil. Gases may liquefy when they cool, as is the case with water vapor. This occurs as the molecules in the gas slow down and lose energy. Solids may liquefy when they heat up; molten lava is an example of solid rock which has liquefied as a result of intense heat. Gases
: A gas has neither a definite volume nor a definite shape. Some gases can be seen and felt, while others are intangible for human beings. Examples of gases are air, oxygen, and helium. Earth's atmosphere is made up of gases including nitrogen, oxygen, and carbon dioxide. Plasma: Plasma has neither a definite volume nor a definite shape. Plasma often is seen in ionized gases, but it is distinct from a gas because it possesses unique properties. Free electrical charges (not bound to atoms or ions) cause the plasma to be electrically conductive. The plasma may be formed by heating and ionizing a gas. Examples of plasma include stars, lightning, fluorescent lights, and neon signs.
Explanation:
exosphere is the outer layer of the atmosphere
Answer:
t = 121 nm
Explanation:
Given:
- Silicon refractive index n_1 = 3.50
- Silicon dioxide refractive index n_2 = 1.45
- The wavelength of light in air λ_air = 700 nm
Find:
What is the minimum coating thickness that will minimize the reflection at the wavelength of 700 nm.
Solution:
- The film’s index of refraction (n_2 = 1.45) is less than that of solar cell (n_1 =
3.50) so there will be a reflective phase change at the first boundary (air–film), and at the second boundary (film–solar cell). The relationship for destructive interference for two reflective phase changes is as follows:
2*t = (m + 0.5)*(λ/n_2) m = 0, 1, 2, ....
- Solve for thickness t where m = 0 (for the thinnest film).
t = 0.25*(λ/n_2)
t = 0.25*(700/1.45)
t = 121 nm ... (rounded to 3 sig. fig)
- This coating technique is important to increase the efficiency of solar cells; If the light can’t reflect, then it must transmit into the solar cell material.
