Consider an ac network shown below. Impedance Z₁ = j4 is purely reactive and corresponds to an inductor, impedance Z2 Ris purely resistive corresponds to a resistor, and impedance Z3 = -jXc is purely reactive and corresponds to a capacitor (i.e. Xc > 0). If the complex power supplied by the source is S = 50 VA (i.e. source supplies only real power and no reactive power), then the value of the unknown resistor R that is consistent with this information is Z₁ j4 V₂ RZ₂jXZ3 = 20/0° ---DO
Answers
The value of the unknown resistor R that is consistent with the given information is approximately 6.75 ohms.
What is the value of the unknown resistor R in the given AC network?To determine the value of the unknown resistor R in the given AC network, we need to analyze the complex power supplied by the source.
The complex power S supplied by the source can be expressed as the sum of the real power P and the reactive power Q:
S = P + jQ
Given that the source supplies only real power and no reactive power, the complex power S simplifies to:
S = P
We can calculate the complex power using the formula:
S = V * I*
where V is the complex voltage and I* is the complex conjugate of the current.
Let's analyze the given network step by step:
1. Impedance Z₁ = j4 corresponds to an inductor. The impedance of an inductor is given by:
Z₁ = jωL
where ω is the angular frequency and L is the inductance. Here, Z₁ = j4 implies that ωL = 4.
2. Impedance Z₂ is purely resistive, which means it corresponds to a resistor. The impedance of a resistor is given by:
Z₂ = R
where R is the resistance. We need to find the value of R.
3. Impedance Z₃ = -jXc corresponds to a capacitor. The impedance of a capacitor is given by:
Z₃ = -j/(ωC)
where ω is the angular frequency and C is the capacitance. Here, Z₃ = -jXc implies that 1/(ωC) = Xc.
Now, let's calculate the complex power supplied by the source:
S = V₂ * I₂*
Since the impedance Z₁, Z₂, and Z₃ are connected in series, the total impedance Z_total can be expressed as the sum of individual impedances:
Z_total = Z₁ + Z₂ + Z₃
= j4 + R - jXc
= R + j(4 - Xc)
Let's assume the complex current through the circuit is I_total = I * exp(jθ).
The voltage across the total impedance is given by Ohm's law:
V_total = Z_total * I_total
= (R + j(4 - Xc)) * (I * exp(jθ))
= (R + j(4 - Xc)) * I * exp(jθ)
The complex power supplied by the source can now be calculated as:
S = V_total * I_total*
= [(R + j(4 - Xc)) * I * exp(jθ)] * [I * exp(-jθ)]
= [(R + j(4 - Xc)) * I * I] * exp(jθ - (-jθ))
= [(R + j(4 - Xc)) * I²] * exp(2jθ)
Given that S = P, we can equate the real parts:
P = Re{[(R + j(4 - Xc)) * I²] * exp(2jθ)}
= Re{[(R + j(4 - Xc)) * I² * exp(2jθ)]}
= Re{[(R + j(4 - Xc)) * I² * (cos(2θ) + j*sin(2θ))]}
The real part of a complex number is given by multiplying it with its conjugate. Therefore, we multiply the above expression with the conjugate of the complex term:
P = Re{[(R + j(4 - Xc)) * I² * (cos(2θ) + j*sin(2θ))] * conj{[(R + j(4 - Xc)) * I² * (
cos(2θ) + j*sin(2θ))}]}
= Re{[(R + j(4 - Xc)) * I² * (cos(2θ) + j*sin(2θ))] * [(R + j(4 - Xc)) * I² * (cos(2θ) - j*sin(2θ))]}
Simplifying the above expression:
P = Re{[(R + j(4 - Xc)) * I² * (cos²(2θ) + sin²(2θ))]}
= Re{[(R + j(4 - Xc)) * I²]}
= Re{[(R + j(4 - Xc)) * -I²]}
= Re{[-(R + j(4 - Xc)) * I²]}
Since the supplied complex power S is 50 VA (real power only), we can equate it to the real part of the above expression:
50 = Re{[-(R + j(4 - Xc)) * I²]}
Now, let's substitute the given value of Z₁ = j4 and simplify the equation further:
50 = Re{[-(R + j(4 - Xc)) * I²]}
= Re{[-(R + j4 + jXc) * I²]}
= Re{[-(R + j4 + jXc) * (V₂ / Z₂)²]}
= Re{[-(R + j4 + jXc) * (V₂ / R)²]}
= Re{[-(1 + j(4/R) + j(Xc/R)) * (V₂)²]}
Since the real power is given as 20/0°, we can equate it to the real part of the above expression:
20 = Re{[-(1 + j(4/R) + j(Xc/R)) * (V₂)²]}
The right side of the equation is a complex expression, but its real part should be equal to 20. Therefore, we can disregard the imaginary part and write:
20 = -(1 + j(4/R) + j(Xc/R)) * (V₂)²
To remove the complex notation, we can equate the magnitudes and the angles separately:
Magnitude:
|20| = |-(1 + j(4/R) + j(Xc/R)) * (V₂)²|
20 = |(1 + j(4/R) + j(Xc/R)) * (V₂)²|
Angle:
0° = arg(-(1 + j(4/R) + j(Xc/R)) * (V₂)²)
Simplifying the magnitude equation:
20 = |(1 + j(4/R) + j(Xc/R)) * (V₂)²|
= |(1 + j(4/R) + j(Xc/R))| * |(V₂)²|
= sqrt((1 + 4²/R² + Xc²/R²)) * |(V₂)²|
Squaring both sides:
400 = (1 + 4²/R² + Xc^2/R²) * |(V₂)²|
400 = (1 + 16/R² + Xc^2/R²) * |(V₂)²|
400 = (1 + 16/R² + Xc^2/R²) * |V₂|²
Since |V₂|² is a real value, we can rewrite it as (V₂)²
Learn more about resistor
brainly.com/question/30672175
#SPJ11
Related Questions
What makes water stick to itself and other molecules?
Answers
Water molecules may adhere to itself and to other molecules because of the existence of hydrogen bonds.
A hydrogen bond is a weak electrostatic attraction between a partly positive hydrogen atom in one molecule and a partially negative atom in another (typically oxygen or nitrogen). Each molecule of water comprises two hydrogen atoms and one oxygen atom. The oxygen atom is somewhat negatively charged, while the hydrogen atom is partially positively charged.
When two water molecules come into contact with one other, the partly negative oxygen atom of one water molecule is attracted to the partially positive hydrogen atoms of the other water molecule, resulting in the formation of a hydrogen bond. Water molecules stay together due to hydrogen bonding, giving water its distinctive features such as high surface tension and cohesiveness.
Water can also cling to other molecules with partial charges, such as polar compounds such as salt or sugar. A water molecule's partly negative oxygen atom can attract positively charged sodium or sugar molecules, forming a connection between them.
For more such questions on molecules, click on:
https://brainly.com/question/15379971
#SPJ4
help, anyone?? please:/
Answers
A billion years ago, Earth and its moon were just 200000 kilometers apart. Express this distance in meters.
Answers
Answer:
The value is \(x = 200000000 \ m\)
Explanation:
From the question we are told that
The distance between the earth and the moon is \(d = 200000 \ km\)
Generally ,
\(1 \ km = 1000 \ m\)
\(200000 \ km \to x \ m\)
=> \(x = \frac{200000 * 1000}{1 }\)
=> \(x = 200000000 \ m\)
What is the function of the thesis statement?
to explain your opinion and the main ideas
to introduce your topic and main ideas
to persuade the reader to think or act a certain way
to summarize the information in the essay
Answers
Answer: A thesis statement states the main idea of an essay or assignment.
Explanation: A thesis statement is put in the introduction of a writing assignment to tell the reader the opinion or judgement of the writer. What the writer infers about a book or personal experience. Examples are argumentative essays or literary device essays.
Are three coefficients of expansion alpha bita and gamma universal constant?
Answers
Answer:
As the temperature increases, the volume of the material also increases. This is known as thermal expansion. It can also be explained as the fractional change in the length or volume per unit change in the temperature.
The relation between alpha, beta, and gamma is given in the form of a ratio and the ratio is 1:2:3 and can be expressed as:
alpha=fracbeta2=fracgamma3
Following is the relation between the three:
L = L (1 + α.ΔT)
Where, α is the coefficient of linear expansion
A = A (1 + β.ΔT)
Where, β is the coefficient of aerial expansion
V = V (1 + γ.ΔT)
Where, γ is the coefficient of cubical expansion
V = V + γV.ΔT
V = V (1 + γ.ΔT)
L3 = L3 (1 + α.ΔT)3
L3 = L3 (1 + 3α.ΔT + 3α2.ΔT2 + α3.ΔT3)
L3 = L3 (1 + 3α.ΔT)
Alpha, beta, and gamma are related to one another in the form of a ratio, and that ratio is 1:2:3, and yes they are universal constants.
What is expansion?A substance's volume expands while its mass stays constant. Heating is typically the cause of expansion. When a substance is heated, the molecular bonds separating its particles weaken, the particles move more quickly, and the substance expands as a result.
Determine the relation as shown below,
L = L (1 + α × Δ T)
here, α is the coefficient of linear expansion
A = A (1 + β × Δ T)
here, β is the coefficient of aerial expansion
V = V (1 + γ × Δ T)
here, γ is the coefficient of cubical expansion
V = V + γ × V × Δ T
V = V (1 + γ × ΔT)
L3 = L3 (1 + α × Δ T)3
L3 = L3 (1 + 3α × ΔT + 3α2 × ΔT2 + α3 × ΔT3)
L3 = L3 (1 + 3α × Δ T)
To know more about expansion:
https://brainly.com/question/28942019
#SPJ2
What is units and dimensions? what are dimensions less quantities?
Answers
Answer:
A dimension is a measure of a physical variable.
Unit is a way to assign a number or measurement to that dimension.
In dimensional analysis, a dimensionless quantity is a quantity to which no physical dimension is assigned, also known as a bare, pure, or scalar quantity or a quantity of dimension one, with a corresponding unit of measurement is the SI of the unit one, which is not explicity shown.
the diagram shows an aeroplane flying. There are horizontal forces acting on the aeroplane, as shown in the diagram (a) calculate the resultant horizontal force on the aeroplane resultant force= direction of resultant force=
Answers
1. The resultant horizontal force on the aeroplane is
2. The direction of the resultant force is left
How do i determine the resultant force and direction?The following data were obtained from the question:
Magnitude of force to the left (F₁) = 12000 NMagnitude of force to the right (F₂) = 8000 NResultant force (R) = ?The resultant force acting on the aeroplane can be obtained as illustrated below:
Resultant force = Magnitude of force to the left 1 (F₁) - Magnitude of force to the right (F₂)
= 12000 - 8000
= 4000 N to the left
Thus, we can conclude that the resultant force is 4000 N and the direction of the aeroplane is to the left
Learn more about force:
https://brainly.com/question/12282988
#SPJ1
Part E Adjust the temperature at 5900 K. What is the color of a star at this temperature?
Answers
The color of the star at 5900K is close to the color of the sun, that is yellow. So the color of the star at 5900K will be yellow.
The color of light emitted by a hypothetical opaque, non-reflective body at a specific temperature expressed in kelvins is known as color temperature. Regardless of the temperature of other light sources, the color of their light is classified using the color temperature scale.
One aspect of visible light is color temperature. Lower color temperatures (2700–3000 K) are referred to as "warm colors," while color temperatures over 5000 K are referred to as "cool colors" (bluish) (yellowish).
The Sun closely resembles a radiator with a black body. The total radiative power per square unit determines the effective temperature, which is approximately 5780 K. Over the atmosphere, sunlight has a color temperature of approximately 5900 K.
Therefore, the star with a temperature around 5900K will have a color similar to that of the sun which is yellow.
LEARN MORE ABOUT SUN HERE:
https://brainly.com/question/15837114
#SPJ9
how to keep nick alive house of ashes
Answers
"House of Ashes" is a video game that follows a group of soldiers who are trapped underground and must fight for survival against supernatural creatures.
Nick is one of the characters in the game, and keeping him alive can be challenging. Here are some tips to help you keep Nick alive in "House of Ashes":
Pay attention to Quick Time Events (QTEs): During certain action sequences in the game, you will need to react quickly to avoid danger.
Keep an eye out for QTE prompts on the screen and respond quickly to keep Nick and the other characters alive.
Choose dialogue options carefully: The choices you make during dialogue scenes can impact how the story unfolds.
Choose dialogue options that align with Nick's personality and try to avoid antagonizing other characters.
Use cover to avoid enemy attacks: When you encounter enemies, use cover to avoid their attacks. Stay behind objects like pillars or walls and peek out to take shots at the enemy.
This can help you avoid taking damage and keep Nick alive.
Work with the other characters: "House of Ashes" is a cooperative game, and you will need to work with the other characters to survive. Pay attention to their needs and help them when necessary.
This can help build trust and improve your chances of keeping Nick alive.
Be cautious when exploring: When you are exploring the underground tunnels, be cautious and watch out for traps and other dangers.
Move slowly and carefully to avoid setting off traps or attracting the attention of enemies.
By following these tips, you can improve your chances of keeping Nick alive in "House of Ashes".
However, keep in mind that the game has multiple possible endings, and your choices will impact the outcome of the story.
To know more about House of Ashes refer here
brainly.com/question/24780407#
#SPJ11
TRUE OR FALSE
The direction that a front is moving is determined by the point of the triangles or half circles.
!!BRAINLIEST only if the answer is correct !!
Answers
True, Fronts are boundaries between different air masses, and their direction of movement is indicated by symbols such as triangles and half circles on weather maps.
What are fronts and how is their direction of movement depicted on weather maps?
In meteorology, a front is a boundary between two different air masses that have different temperature, humidity, or pressure characteristics. Fronts can be depicted on weather maps using symbols, such as triangles or half circles, to represent the direction of movement of the front.
The orientation of the symbols is determined by the direction of the movement of the front, with the point of the triangles or the curved side of the half circles facing in the direction that the front is moving. By looking at the symbols on a weather map, meteorologists can determine the location, speed, and direction of fronts, which are important factors in forecasting weather conditions.
To learn more about meteorologists, visit: https://brainly.com/question/26550989
#SPJ1
Two research groups getting together and sharing thoughts, ideas, and research results is known as ...
a) modeling
b) risk taking
c) observation
d) collaboration
Answers
Answer:
D
Explanation: collaboration
thats wut i think
Consider the plane electromagnetic wave in vacuum (in SI units) given by the expressions Ex=0,Ey=2cos[2π×1014(t−x/c)+ π/2], and Ez=0.(a) What are the frequency, wavelength, direction of motion, amplitude, initial phase angle, and polarization of the wave?(b) Write an expression for the magnetic flux density.
Answers
- Frequency: The frequency of the wave is 1014 Hz.
- Wavelength: The wavelength of the wave can be calculated using the formula λ = c/f, where c is the speed of light in vacuum and f is the frequency. Thus, the wavelength is λ = c/f = 3 × 10^8 m/s ÷ 1014 Hz = 2.97 × 10^-4 m.
- Direction of motion: The wave is traveling in the x-direction.
- Amplitude: The amplitude of the wave is 2.
- Initial phase angle: The initial phase angle of the wave is π/2.
- Polarization: The wave is polarized in the y-direction.
The wavelength of the wave can be calculated using the formula λ = c/f, where c is the speed of light in vacuum and f is the frequency. Thus, the wavelength is λ = c/f = 3 × 10^8 m/s ÷ 1014 Hz = 2.97 × 10^-4 m.
(b) To find the expression for the magnetic flux density, we can use the relation between the electric and magnetic fields in vacuum given by B = (1/c) × E, where B is the magnetic flux density, c is the speed of light in vacuum, and E is the electric field. Therefore, the magnetic flux density for this wave can be written as:
Bx = 0
By = (1/c) × 2cos[2π×1014(t−x/c)+ π/2] = (2/c)cos[2π×1014(t−x/c)+ π/2]
Bz = 0
Note: As an AI language model, I provided a factual answer based on the given data. However, I suggest verifying the answer with a qualified expert in the field for the best and most accurate results.
learn more about frequency here
https://brainly.com/question/30611426
#SPJ11
- Frequency: The frequency of the wave is 1014 Hz.
- Wavelength: The wavelength of the wave can be calculated using the formula λ = c/f, where c is the speed of light in vacuum and f is the frequency. Thus, the wavelength is λ = c/f = 3 × 10^8 m/s ÷ 1014 Hz = 2.97 × 10^-4 m.
- Direction of motion: The wave is traveling in the x-direction.
- Amplitude: The amplitude of the wave is 2.
- Initial phase angle: The initial phase angle of the wave is π/2.
- Polarization: The wave is polarized in the y-direction.
The wavelength of the wave can be calculated using the formula λ = c/f, where c is the speed of light in vacuum and f is the frequency. Thus, the wavelength is λ = c/f = 3 × 10^8 m/s ÷ 1014 Hz = 2.97 × 10^-4 m.
(b) To find the expression for the magnetic flux density, we can use the relation between the electric and magnetic fields in vacuum given by B = (1/c) × E, where B is the magnetic flux density, c is the speed of light in vacuum, and E is the electric field. Therefore, the magnetic flux density for this wave can be written as:
Bx = 0
By = (1/c) × 2cos[2π×1014(t−x/c)+ π/2] = (2/c)cos[2π×1014(t−x/c)+ π/2]
Bz = 0
Note: As an AI language model, I provided a factual answer based on the given data. However, I suggest verifying the answer with a qualified expert in the field for the best and most accurate results.
learn more about frequency here
https://brainly.com/question/30611426
#SPJ11
and that laser beams are more than science fiction weapons. Laser beams are instruments of the future
the laser beam.
Which change would be MOST helpful if the author wished to make the passage more formal?
A changing Star Wars to a more current movie
B removing the first sentence of the second paragraph
Cremoving or changing the second and third paragraphs
D removing or changing all of the first-person sentences
LISTEN
Answers
To make the passage more formal, Remove or change all of the first-person sentences. The correct option is D.
If the author wants to make the passage more formal, it is important to eliminate or modify any first-person sentences. First-person statements, such as "the author wished" and "the laser beam," create a less formal tone and a more subjective perspective.
Option A, changing Star Wars to a more current movie, is not necessary for making the passage more formal. The reference to Star Wars is not inherently informal or inappropriate in a formal context. However, removing the first-person sentences would be more effective in achieving a formal tone.
Option B, removing the first sentence of the second paragraph, may disrupt the flow of the passage but would not necessarily make it more formal. The focus should be on removing or modifying the first-person statements instead.
Option C, removing or changing the second and third paragraphs, is not necessary to make the passage more formal. The content of those paragraphs is not inherently informal or unprofessional. Again, the emphasis should be on addressing the first-person sentences.
Therefore, the most effective change to make the passage more formal would be D, removing or changing all of the first-person sentences. By doing so, the author can eliminate the subjective perspective and achieve a more objective and formal tone.
To learn more about the Tone click:
brainly.com/question/19307958
#SPJ1
11. Compare the
luminosity of a white
dwarf to the sun.
Answers
The luminosity of a white dwarf is smaller than that of the Sun.
What is a white dwarf?
A white dwarf is a stellar core remnant composed mostly of electron-degenerate matter.
A white dwarf is very dense: its mass is comparable to the Sun's, while its volume comparable to the Earth's.
What is the luminosity of a white dwarf as compared to sun?A white dwarf's faint luminosity comes from the emission of residual thermal energy; no fusion takes place in a white dwarf.
After a billion years the typical white dwarf is down to 0.001 the luminosity of the Sun.
Thus, the luminosity of a white dwarf is smaller than that of the Sun.
Learn more about luminosity here: https://brainly.com/question/6933301
#SPJ1
What is the momentum of a 30-kg dog running
at a speed of 6 m/s?
Answers
The momentum of a 30-kg dog running at a speed of 6 m/s is 180kgm/s.
What is Momentum?
This is referred to as a measurable quantity of movement in a body or object and is used in science to define the quantity of motion.
It is also known as the product of the mass and velocity of an object and can be calculated by the following below:
Mass = 30kg dog, velocity = 6 m/s
Therefore the momentum of the body is 30kg × 6m/s = 180kgm/s.
This is however the correct choice.
Read more about Momentum here https://brainly.com/question/402617
#SPJ1
Help please!
Two rope tows operate on the same ski slope. When both are operating with equal loads, Tow A can move faster than
Tow B.
-Which does the most work?
1. they both do the same work
2. Tow B
3. Tow A
-Which has the most power?
1. they both have the same power
2. Tow B
3. Tow A
Answers
Answer: They both do the same amount of work but Tow A has more power
Explanation:
What is the relationship between increase speed of a car and energy in a
collision?
Answers
Hello,
QUESTION)✔We have : Ek = 1/2m x v²In other words, when the speed doubles the collision energy of the car, or simply the kinetic energy, is multiplied by two.
The center-seeking change in velocity of an object moving in a circle is .
tangential speed
centripetal speed
tangential acceleration
centripetal acceleration
Answers
Answer:
centripetal acceleration
just took the test
The center-seeking change in velocity of an object moving in a circle is said to be centripetal speed.
Centripetal often means center-seeking. Centripetal forces are said to always move toward the center of the circular path.Acceleration often deals with the rate of change in velocity of an object.
Velocity can be measured by dividing the distance travelled by an object versus the time interval it took to cover that distance
In uniform circular motion, the direction of the velocity often change a lot, so there is always an associated acceleration.
Learn more from
https://brainly.com/question/9513266
An object has more elastic potential energy if...
Answers
A 230 v mains powered electrical drill draws a current of 2.5 A calculate the power of the drill at use
Answers
A spring has a force of 2.0N and an extension of 0.30m. What will the extension be if the force applied is 6 N.
Will mark as brainliest
Answers
Answer:
0.9 m
Explanation:
Hooke’s Law
\(\large\boxed{F = ke}\)
where:
F is the force in newtons (N).k is the 'spring constant' in newtons per metre (N/m).e is the extension in metres (m).Given values:
F = 2.0 Ne = 0.30 mSubstitute the given values into the formula to find k:
\(\implies 2.0=0.30k\)
\(\implies k=\dfrac{2.0}{0.30}\)
\(\implies k=\dfrac{20}{3}\; \sf N/m\)
To find the extension if the force applied is 6 N, substitute the found value of k and the given value of F into the formula and solve for e:
\(\implies 6=\dfrac{20}{3}e\)
\(\implies 18=20e\)
\(\implies e=\dfrac{18}{20}\)
\(\implies e=0.9\; \sf m\)
Samanthawalks along a horizontal path in the direction shown the curved path is a semi circle with a radius of 2 m while the horizontal part is for me what is the magnitude of displacement
Answers
Answer:
Explanation:
Samantha walks along a horizontal path in the direction shown the curved path is a semi circle with a radius of 2 m while the horizontal part is for me what is the magnitude of displacement
Displacement is given by the straight line distance between P and Q. Displacement will be length of straight line joining P and Q
a semi circle with a radius of 2 m
Length of this straight line=4+diameter
=4+(2*2)
=8 m
As time goes on, the ENTROPY in a closed system should increase. This is because of which Law?
A) Conservation of Energy
B) Conservation of Momentum
C) 1st Law of Thermodynamics
D) 2nd Law of Thermodynamics
E) None of these
Answers
Answer:
The answer is D
The second law of thermodynamics
60 PTS + BRAINLIEST
1. A virtual image is 3 meters behind a flat mirror and it is 2 meters tall. What is the height and distance from the mirror, for the object?
2. A concave mirror has a focal length of 1 meter. An object is 2 meters from the mirror. What is the image distance from the mirror?
3. Alens has a focal length of -10 cm. If the image of an object is located at -20 cm, what is the distance of the object?
Answers
Answer:
1. The distance of image from the plane mirror is same as the distance of object (person) from the plane mirror but the image is formed behind the mirror.
v=u=3 m
Thus distance between image and the person d=u+v=3+3=6 m
2.A concave mirror has a radius of curvature of 1.0 m. An object is placed 2.0 m in front of the mirror. Can you determine the location of the image (in cm)
1/v = 1/f - 1/u = 1/50 - 1/200 = 4/200 - 1/200 = 3/200
v = 200/3 c
NUMBER 3 Ans: 18.75 cm.
Sorry dogay kaau ha please follow my account and rate 5 star thank you
what is the general term for a device that transforms the energy of an electric current into another useful form of energy?
Answers
The general term for a device that transforms the energy of an electric current into another useful form of energy is an electrical transducer.
Electrical transducers are used to convert energy of one kind into energy of another, such as converting electrical energy into mechanical energy or vice versa. They can also be used to convert energy from one form to another, such as converting electrical energy into heat, light, or sound.
Electrical transducers have a wide range of applications, from powering small household appliances to providing power to large industrial machines and even providing power to vehicles. For example, a car’s alternator is an electrical transducer that converts mechanical energy from the car’s engine into electrical energy to power the car’s electrical systems.
Learn more about Electrical transducers:
https://brainly.com/question/22529120
#SPJ4
Can the sun explain global warming? ( 2 points) Suppose that the Earth has warmed up by 1 K in the last hundred years. i) How much would the solar constant have to increase to explain this? ii) Compare this to the observed fluctuation of the solar constant over the past 400 years (shown in class) For part (i), begin with the standard 'blackbody' calculation from class, that is: set α=0.30, and assume that the Earth acts as a blackbody in the infrared.
Answers
No, the sun cannot explain global warming. Global warming is a phenomenon in which the temperature of the Earth's surface and atmosphere is rising continuously due to human activities such as deforestation, burning of fossil fuels, and industrialization.
This increase in temperature cannot be explained only by an increase in solar radiation.There are several factors which contribute to global warming, including greenhouse gases such as carbon dioxide, methane, and water vapor. These gases trap heat in the Earth's atmosphere, which causes the planet's temperature to rise. The sun's radiation does contribute to global warming, but it is not the main cause.
i) To calculate the increase in solar radiation that would cause the Earth to warm up by 1 K, we can use the following formula:ΔS = ΔT / αWhere ΔS is the increase in solar constant, ΔT is the increase in temperature, and α is the Earth's albedo (reflectivity).α = 0.30 is the standard value used for the Earth's albedo.ΔS = ΔT / αΔS = 1 K / 0.30ΔS = 3.33 W/m2So, to explain the increase in temperature of 1 K over the last hundred years, the solar constant would need to increase by 3.33 W/m2.
ii) The observed fluctuation of the solar constant over the past 400 years has been around 0.1% to 0.2%. This is much smaller than the 3.33 W/m2 required to explain the increase in temperature of 1 K over the last hundred years. Therefore, it is unlikely that the sun is the main cause of global warming.
The sun cannot explain global warming. While the sun's radiation does contribute to global warming, it is not the main cause. The main cause of global warming is human activities, particularly the burning of fossil fuels, which release large amounts of greenhouse gases into the atmosphere.
To know more about global warming :
brainly.com/question/29625243
#SPJ11
find the electric field (in n/c) at a point r =1.9 m above a point charge q= -90 μc. take upwards to be positive.
Answers
The electric field, resulting from a point charge q = -90 μC, at a point 1.9 m above is approximately -1.2 × 10⁵ N/C. The field is directed downward, consistent with the given positive direction.
Determine how to find the electric field?The electric field E due to a point charge q at a distance r from the charge is given by Coulomb's law:
E = k * (q / r²),
where k is the electrostatic constant (k = 8.99 × 10⁹ N m²/C²).
In this case, the charge q = -90 μC = -90 × 10⁻⁶ C, and the distance r = 1.9 m.
Plugging these values into the equation, we have:
E = (8.99 × 10⁹ N m²/C²) * (-90 × 10⁻⁶ C) / (1.9 m)²
≈ -1.2 × 10⁵ N/C.
The negative sign indicates that the electric field is directed downward, as specified in the problem. Therefore, the electric field due to a point charge q = -90 μC at a point 1.9 m above is approximately -1.2 × 10⁵ N/C, directed downward as specified.
To know more about Coulomb's law, refer here:
https://brainly.com/question/506926#
#SPJ4
What would the velocity of an object be if it was on a 1.75m
rope and took 4 seconds to go around 2 revolutions?
Answers
Answer:
T = 4 sec / 2 = 2 sec period of revolution
S = 2 pi R = 2 * pi * 1.75 m = 11 m
V = S / T = 11 m / 2 sec = 5.5 m/s speed of object
The Gauss-Markov Theorem states that if assumptions 1-5 are
satisfied then OLS is BLUE. Briefly explain what the B stands
for
Answers
The B in BLUE stands for "Best Linear Unbiased Estimator." The Gauss-Markov Theorem states that if assumptions 1-5 are satisfied, then the Ordinary Least Squares (OLS) estimator is the Best Linear Unbiased Estimator.
Let's break down the meaning of each term in the acronym:
1. Best: The OLS estimator is considered the best because it has the smallest variance among all linear unbiased estimators. In other words, it is the most efficient estimator among all unbiased estimators.
2. Linear: The OLS estimator is a linear combination of the dependent variable and the independent variables. It assumes a linear relationship between the variables.
3. Unbiased: The OLS estimator is unbiased, meaning that on average it will provide an estimate that is equal to the true population parameter being estimated. This implies that there is no systematic error in the estimation process.
4. Estimator: The OLS estimator is a statistical technique used to estimate unknown parameters in a linear regression model. It calculates the best-fit line that minimizes the sum of squared residuals.
The Gauss-Markov Theorem is important because it provides conditions under which the OLS estimator is the best among all linear unbiased estimators.
It ensures that if assumptions 1-5 are met, the OLS estimator will have the smallest variance and, be the most efficient estimator.
The Gauss-Markov Theorem states that if assumptions 1-5 are satisfied, the OLS estimator is the Best Linear Unbiased Estimator (BLUE) because it is the most efficient and unbiased estimator among all linear unbiased estimators.
To know more about Gauss-Markov Theorem visit:
https://brainly.com/question/32702043
#SPJ11
A gray kangaroo can bound across a flat stretch of ground with each jump carrying it 8.0 m from the takeoff point.
If the kangaroo leaves the ground at a 22˚ angle, what is its takeoff speed?
What is its horizontal speed?
Answers
The kangaroo's horizontal speed will be 9.7 m/s and its departure speed will indeed be 10.65 m/s.
What is the sound's velocity?By observing the pace at which this compressed region moves through the medium, we may determine the sound speed. The sound wave travels at a speed of around 343 meters per second in low humidity at 20 degrees Celsius.
Briefing:The following equation relates the distance to the direction and initial velocity:
d = [v₀²sin2θ]/g, where θ – the angle of the jump.
Thus, v₀² = gd / (sin2θ) = (9.8×8)/0.69 = 113.62
v₀ = 10.65 m/s ( the take off speed).
The horizontal velocity equals:
vₓ = v₀cos 22° = 10.65 m/s × 0.92 = 9.7 m/s
To know more about speed visit:
https://brainly.com/question/28224010
#SPJ1