Answer:
The thermal efficiency, [tex]\eta _{reheat}[/tex], of the Rankine cycle with reheat is 36.81%
Explanation:
p₁ = 8 MPa = 80 Bars
T₁ = 450°C = 723.15 K
From steam tables, we have;
v₁ = 0.0381970 m³/kg
h₁ = 3273.23 kJ/kg
s₁ = 6.5577 kJ/(kg·K) = s₂
The p₂ = 0.8 MPa
T₂ = Saturation temperature at 0.8 MPa = 170.414°C = 443.564 K
h₂ = 2768.30 kJ/kg
[tex]T_{2'}[/tex] = 400°C = 673.15 K
[tex]h_{2'}[/tex] = at 400°C and 0.8 MPa = 3480.6 kJ/kg
p₃ = 10 kPa = 0.1 Bar
T₃ = Saturation temperature at 10 kPa = 45.805 °C = 318.955 K
h₃ = 2583.89 kJ/kg
h₄ = [tex]h_{3f}[/tex] = 191.812 kJ/kg
The thermal efficiency, [tex]\eta _{reheat}[/tex], of a Rankine cycle with reheat is given as follows;
[tex]\eta _{reheat} = \dfrac{\left (h_{1}-h_{2} \right )+\left (h_{2'}-h_{3} \right )-W_{p}}{h_{1}-\left (h_{4}+W_{p} \right )+\left (h_{2'}-h_{2} \right )}[/tex]
Therefore, we have;
[tex]\eta _{reheat} = \dfrac{(3273.23 -2768.30 ) + (3480.6 -2583.89 ) - 8.04)}{(3273.23 -(191.812 + 8.04) + (3480.6 -2768.30 ) } = 0.3681[/tex]
Which in percentage is 36.81%.
To which category does galaxy #4 belong? Why does it belong in this category?
Answer:
The Galaxy IV satellite belongs to the HS-601 model category. It was engineered by Hughes Space and Communications Company (HSC)
Explanation:
The Galaxy IV belong in this category because it is a communications satellite. It was built for direct television broadcasting, for private business networks and mobile communications.
Cheers!
What type of bond is most likely to form between atoms of the same element when the element is a metal?
Answer:Covalent bond
Explanation:
Find the average velocity if the takeoff velocity of an airplane on a runway is 300 km/hr with an acceleration of 1 m/s2 . A) 30 sec B) 41.7 sec C) 72.2 sec D) 83.33 sec
Answer:
83.33s
Explanation:
velocity=300km/hr ,acceleration =1m/s2
But before we can make this calculation,we have to make sure that both the acceleration and velocity are in the same units.So I decided to Chang the velocity to m/s.
Converting 300km/hr into m/s;
Changing 300km into m=300000m
Changing 1hr into secs=3600sec
Velocity in m/s=83.33m/s
But Time =velocity/acceleration
=83.33/1
=83.33sec
You have to decide what you want. Your question says "Find the average velocity", but the choices you listed are all times, not velocities.
(300 km/hr) x (1 hr / 3600 sec) = 83.33 meters/sec
-- If the airplane starts from rest and accelerates uniformly at 1 m/s², it'll take 83.33 seconds to reach takeoff speed.
-- If it starts from rest and accelerates uniformly to 83.33 m/s, then its average speed is 41.67 m/s no matter what its acceleration may be.
A ray diagram is shown what does the letter x represent?
Answer: angle of incidence
Answer:
A) angle of incidence
Explanation:
e)
The surface area of foot of Bimaba is 150cm? If she weighs 50kg,
how much pressure does she exert on the ground, as she stands on
her one foot? (32666.67 pa)
Answer:
Pressure, P = 32666.66 Pa
Explanation:
It is given that,
Surface area of foot of Bimaba is 150 cm² or 0.015 m².
Her weight is 50 kg
We need to find the pressure does she exert on the ground, as she stands on her one foot. The force acting per unit area is called pressure. It can be given by :
[tex]P=\dfrac{F}{A}\\\\P=\dfrac{mg}{A}\\\\P=\dfrac{50\times 9.8}{0.015}\\\\P=32666.66\ Pa[/tex]
So, the pressure is 32666.66 Pa.
a loop with a break in it that prevents current form flowing is called a(n) blank circuit
Answer: it is called a open circuit
Explanation:
I NEED HELP PLEASE, THANKS!
Find or draw at least two pictures that illustrates Newtons first Law. Write a paragraph describing how each of the pictures you choose illustrates the law.
Explanation:
When a person is standing still, the forces acting on them (weight force pulling down and normal force pushing up) are equal and opposite, so the net force is balanced. So the person will continue to be at rest, unless the net force becomes unbalanced.
When a person falls with a parachute, the forces acting on them (weight force pulling down and air resistance pushing up) are equal and opposite, so the net force is balanced. So the person will continue to fall at the same speed until the net force becomes unbalanced.
Jessica stretches her arms out 0.60 m from the center of her body while holding a 2.0 kg mass in each hand. She then spins around on an ice rink at 1.1 m/s.
a. What is the combined angular momentum of the masses?
b. If she pulls her arms into 0.15 m, what is her new linear speed?
I'm really confused ab the explanations behind this. help, please
Answer:
a.) L = 2.64 kgm^2/s
b.) V = 4.4 m/s
Explanation: Jessica stretches her arms out 0.60 m from the center of her body. This will be considered as radius.
So,
Radius r = 0.6 m
Mass M = 2 kg
Velocity V = 1.1 m/s
Angular momentum L can be expressed as;
L = MVr
Substitute all the parameters into the formula
L = 2 × 1.1 × 0.6 = 1.32kgm^2s^-1
the combined angular momentum of the masses will be 2 × 1.32 = 2.64 kgm^2s-1
b. If she pulls her arms into 0.15 m,
New radius = 0.15 m
Using the same formula again
L = 2( MVr)
2.64 = 2( 2 × V × 0.15 )
1.32 = 0.3 V
V = 1.32/0.3
V = 4.4 m/s
Her new linear speed will be 4.4 m/s
I NEED HELP PLEASE, THANKS! :) Why is it a good idea to touch a metal pole, or similar conductor, before filling up a car with gas?
Answer:
While filling up the gas, a static discharge can take place which is really dangerous for us. It can even ignite a fire at the gas station. Touching the metal pole or any conductor will pass all of the charge into the Earth and thus we'll keep safe.
Answer:
It is a good idea to touch a metal pole or similar conductor before filling up a car with gas because it will discharge any static electricity on you, making it safer for everyone.
Explanation:
I NEED HELP PLEASE, THANKS :) What does it mean when white light is diffracted and at a particular location the color seen is blue?
Answer:
This is because white light consists of 7 colours with different angles o deviation or retraction.
Explanation:
When a narrow beam of light is refracted by a prism the light spreads into a band of colours (called the spectrum of light )
But in this case if a blue colour is observed it is due to the angle of refraction ,for instance red is refracted the least and hence is seen
Answer:
When while light is diffracted and at a particular location blue color is seen, this means that blue color is reflected while all other colors will be absorbed. When the blue color is seen denotes the shortest wavelength being reflected and all other being absorbed at the specified location.
You have a graduated cylinder that you use to measure volume. The cylinder
is marked in 1 ml increments. Which measurement made using this cylinder
contains the correct number of significant digits?
A. 35.5 ml
B. 320.01 ml
C. 75.333 ml
D. 21 ml
Answer:
35.5 ml
Explanation:
The other guy made me get the question wrong lol here ya go good luck
What kind of force are you using when you squish a marshmallow?
Answer:
Compression
Explanation:
I would think it would be compression because you are compressing the marshmallow, and pushing it down until its compact.
Answer: Compression, I to had to get an answer for this but imma help you out :)
The coldest layer of Earth’s atmosphere is the __________. a. troposphere c. mesosphere b. stratosphere d. thermosphere
Answer: c.mesosphere
Explanation: Temperatures can reach lows of -90 degrees Celsius in the mesosphere, making it the coldest layer of the earth's atmosphere. The mesosphere extends above the stratosphere and ranges from 50 km to 87 km above the surface.
What activity level should participants be in when exercising in their target heart rate zone
Answer:
La frecuencia cardíaca objetivo durante las actividades de intensidad moderada es aproximadamente del 50 al 70% de la frecuencia cardíaca máxima, mientras que durante la actividad física intensa es de, aproximadamente, entre el 70 y el 85% del valor máximo.
A ball is thrown at a wall with a velocity of 5 m/s and bounces off at 4 m/s as shown in the diagram. If the impulse provided by the wall is 3 Nm, then what is the mass of the ball?
Answer:
m = 3 kg
Explanation:
It is given that,
Initial speed of a ball is 5 m/s, u = 5 m/s
Final speed of a ball is 4 m/s, v = 4 m/s (as it bounces)
Impulse provided by the wall is -3 N-m (impulse is provided in opposite direction)
We need to find the mass of the ball. Impulse provided to an object is given by the change in its momentum as :
J = m(v-u)
m is mass of the ball
[tex]m=\dfrac{J}{(v-u)}\\\\m=\dfrac{-3}{(4-5)} \\\\m=3\ kg[/tex]
So, the mass of the ball is 3 kg.
Garret, Melody and Tony start their school day with brand new pencils. By the end of the day, they want to see who used his or her pencil the most. They decide that the shortest pencil will be the most used, and the longest pencil would be the least used. How should the students determine which pencil was used the most?
THEY SHOULD COMPARE THE LENGTH OF PENCILS WITH EACH OTHER .
HOPE IT HELPS.PLEASE MARK AS BRAINLIEST AND FOLLOW ME ......Which of the following represents the equation of motion of a steel ball thrown into a viscous liquid when it is moving with an acceleration a ?(A) W-V-U=ma (B)W-U=ma-V (C)W-U-V=0 (D)U-V=W
Answer: A
Explanation: When a steel ball is thrown into a viscous liquid, three forces will act on the ball.
1.) The viscous drag force V which is acting upward
2.) The buoyant force U which is acting upward and
3.) The weight of the ball W. Which is acting downward.
When it is moving with an acceleration a, the weight W will be greater than U and V
Since Force = ma.
The resultant vector force will be
W - V - U = ma
All matter is made up of________ called atoms or molecules
Which property of sugar makes it different from white crystalline sand?
Answer:
The property of sugar which makes it different from sand is that sugar can dissolve in water. Explanation: however the power of dissolving of sand is not present. This is due to the presence of interaction between sugar and water.
Explanation:
I hope that was useful
hi please I need help with my mMATHEMATICS ASSIGNMENTS
1. Find the value of x and y in the following ratios
a. 3:5 = x:20
b.11:35 = 66: y
2. In a village of 375 children under the age of 10. If 68% of them have had malaria, how many children have escaped the disease?
3. Five buses need 3 trips to take 450 students to the stadium to watch a concert. How many trips would the 3 buses need to take the same number of students?
4. The ratio of girls to boys in a boarding school is 2:7. If there are 1,251 students in the school:
a. How many of the students are girls?
b. What percentage of the students are boys?
5. An old carpet which now costs #1 000, was sold for #1 400 when new. Calculate the percentage decrease.
6. The cost of petrol is #65 per litre. What is the percentage increase if it is sold for #105 per litre by a dealer during fuel scarcity?
Answer:
1
(a) Ans we are applying the formula
product of means = product of extremes
So according to the formula 5x = 60
x= 60/5
x = 12
(b) Ans we are applying the formula
product of means = product of extremes
2310=11 y
y = 2310/11
y = 210
Explanation:
(a)In product of means we multiply inner values with each other like in this case for solution of a part 5 and x are inner values and in product of extremes we multiply outer value like in case of solution for a 3 and 20 are outer values.
What are the four main reasons as to why, despite having an abundance of minerals and natural resources, Pakistan has been unable to realize its potential and has not been able to succeed like other countries having similar resources?
please answer me I am so much worry I will mark you as brainy and follow you also
Answer:
GDP growth rate is low
Political instability
Lack of technical skills due to low literacy rate
Pressure from neighboring countries
Explanation:
Gross Domestic Product growth rate of Pakistan is much lower than many developed countries. The GDP growth rate for Pakistan is nearly 5% which is not even stable and it variate from plans. Due to which Pakistan is unable to use its available resources to the fullest. Also one of major issue is political instability in the country. After the loss of great leader Quaid e Azam Pakistan has not faced any loyal leader till date.
Noise pollution, health issues, lack of provision of basic necessities to many are few other factors which give rise to poor law and order situation in the country. Lack of availability of heavy machinery and poor infrastructure has contributed to the country decline. There is abundance of natural resources in the country but due to these issues the country is unable to deal with the challenges.
The pressures from neighboring countries have made the situation even worst. The heavy loan burden is restricting the country from development. The covenants imposed by the lenders have limited the country's ability to use its natural resources and become stable.
A train starts from rest .It moves through 1km in 100s with uniform accelaration . What will be its speed at the end pf 100 s
Answer:
Explanation:
Distance = 1 km
= 1000m
Time = 100 sec
Speed = distance / time
= 1000 / 100
= 10 m/s
Place the types of radiation in order of INCREASING mass.
Answer & explanation:
Gamma Radiation (γ): Also called gamma rays. Gamma radiation is made of electromagnetic waves, has zero charge and mass, continuously emits heat and has the ability to ionize air and make it conductive of electric current. Beta radiation (β): Beta rays or beta particles, are electrons, negative particles with charge - 1 and mass number 0.Alpha radiation (α): Also called alpha particles or alpha rays, are particles charged by two protons and two neutrons. They have positive charge +2 and mass number 4.
Which property of argon is used in light bulbs?
Answer:
Argon belongs to zero group, i.e., is a noble gas and thus is inert. Hence it will not react with the hot filaments. Hence it is used in fluorescent and incandescent light bulbs to stop the oxygen in the light bulbs from corroding the hot tungsten filament.
Explanation:
A right triangle ABC has sides /AB/ =9cm, /BC/=12cm find /AC/ and angles ACB and ABC if angle BAC= 90°
fdi9bn 08989089089008i uuuuuuri9ij
Indicar verdadero (V) o falso (F) con respecto al movimiento parabólico : la componente horizontal de la velocidad permanece constante. ( ) la componente vertical de la velocidad puede ser nula en un instante. ( ) La velocidad en todo momento es tangente a la trayectoria. ( )
Answer:
a) true, b) true, c) false
Explanation:
Este ejercicio de cinemática se pide revisar varias afirmaciones
a) Cierta. La velocidad horizontales consta
b) cierto. La velocidad vertical disminuye hasta llegar a cero en su altura máxima, la aceleración es negativa
C) False. Si la velocidad es tangente a la trayectoria el movimiento debe ser circular, pero este movimiento es parabólico
Traduction
This exercise in kinematics asks you to review several statements
a) true. The horizontal speed consists
b) true. The vertical speed decreases until it reaches zero at its maximum height, the acceleration is negative
C) False. If the speed is tangent to the path, the movement must be circular, but this movement is parabolic.
With respect to parabolic motion:
the horizontal component of the velocity remains constant is Truethe vertical component of the velocity can be null in an instant is True since the velocity changes with time due to gravitation acceleration. At the highest point of the projectile trajectory, the vertical velocity becomes zero.Speed at all times is tangent to the trajectory is True. The parabolic path of the trajectory is because of the changing vertical velocity.Con respecto al movimiento parabólico:
La componente horizontal de la velocidad permanece constante es True la componente vertical de la velocidad puede ser nula en un instante es True ya que la componente vertical de la velocidad cambia con el tiempo debido a la aceleración de la gravitación. En el punto más alto de la trayectoria del proyectil, la velocidad vertical se vuelve cero. La velocidad en todo momento es tangente a la trayectoria es Verdadera. La trayectoria parabólica de la trayectoria se debe a la velocidad vertical cambiante.Learn more about Parabolic motion:
https://brainly.com/question/4450437
Which is an example of a fission reaction? Check all that apply.
H + H → He 2n
+
239 Pu + n + 1904 Ce + Kr + 2n
295 Am + in → 154 La + 95 Sr + 3 in
13C + H + 4N
Answer:
Check Explanation
The fission reactions include
239 Pu + n → Ce + Kr + 2n
And
295 Am + in → 154 La + 95 Sr + 3 n
Explanation:
A fission reaction is a radioactive reaction in which an atom with a heavy nuclei splits into atoms with smaller or lighter nuclei usually brought about by the attack of a fundamental particle and accompanied by the release of some fundamental particles (neutrons mostly) and energy.
Although, the reactions to be examined aren't totally clear, we can still guess which element is which and know which of the reactions has a heavier nuclei splitting into smaller ones.
1) H + H → He + 2n
Two hydrogen atoms combine to give an helium atom and release neutrons too, showing that here, smaller molecules combine to form a bigger one. Hence, this isn't a fission reaction, rather, it's a fusion reaction.
2) 239 Pu + n → Ce + Kr + 2n
Here, Pu (Plutonium, atomic mass 239), a heavy nuclei that splits into smaller nuclei, Ce (Cerium, atomic mass 140) and Kr (Krypton, atomic mass 84) together with some neutrons to fit the definition of a fission reaction. Hence, this reaction is a fission reaction.
3) 295 Am + n → 154 La + 95 Sr + 3 n
Here, Pu (Americium, atomic mass 295), a heavy nuclei that splits into smaller nuclei, Ce (Lamthanium, atomic mass 154) and Sr (Strontium, atomic mass 95) together with some neutrons to fit the definition of a fission reaction. Hence, this reaction is a fission reaction.
4) 13C + H → 14N
Carbon 13 combines with a hydrogen element to mutate and give nitrogen-14, a heavier nuclei, showing all signs of a nuclear fission and not fission.
Hope this Helps!!!
Answer:
b and c
Explanation:
got it correct on edg
A gas baloon bursts when comes to a high altitude.... Plss answer it
Answer:yess
Explanation:as weather balloons travels from the earth's surface, the air pressure around ballons decreases slowly.As the air gets thinner,the gallons casing gets tighter.
This is due to gas expanding within balloon.The expanding gas causes the balloons to reach maximum height and it burst.
I NEED HELP PLEASE, THANKS! Describe each Newton Law. :)
Explanation:
1st- states that when two bodies interact, they apply forces to one another that are equal in magnitude and opposite in direction.
2nd- states that the time rate of change of the momentum of a body is equal in both magnitude and direction to the force imposed on it. (most important law)
3rd- states that when two bodies interact, they apply forces to one another that are equal in magnitude and opposite in direction. (law of action/reaction)
A diverging lens of focal length 18.0m is used to view a shark that is 90.0m away from the lens. If the image formed is 1.0m long, calculate the: (i) image distance; (ii) length of the shark.
Answer:
i. + 22.5 m ii. 4.0 m
Explanation:
i. Image distance
Using the lens formula
1/u + 1/v = 1/f where f = focal length = + 18.0 m, u = object distance = distance of shark away from lens = + 90.0 m and v = image distance from lens = unknown
So, we find v
1/v = 1/f - 1/u
= 1/+18 - 1/+90
= (5 - 1)/90
= 4/90
v = 90/4
= + 22.5 m
So the image is real and formed 22.5 m away on the other side of the lens.
ii Length of Shark
Using the magnification formula, m = image height/object height = image distance/object distance. image height = 1.0 m where object height = length of shark.
m = image distance/object distance
= v/u
= +22.5/+90
= 0.25
0.25 = image height/object height
So,
object height = image height/0.25
= 1.0 m/0.25
= 4.0 m
So, the length of the shark is 4.0 m