An insulated rigid tank initially contains 1.4-kg saturated liquid water and water vapor at 200°C. At this state, 25 percent of the volume is occupied by liquid water and the rest by vapor. Now an electric resistor placed in the tank is turned on, and the tank is observed to contain saturated water vapor after 20 min. Determine:
(a) the volume of the tank
(b) the final temperature
(c) the electric power rating of the resistor
Solution:
Mass of liquid water and water vapor in the insulated tank initially = 1.4 kg
Temperature = 200 °C
And 25% of the volume by liquid water is steam.
State 1
[tex]$m=\frac{V}{v}$[/tex]
[tex]$m=m_f+m_g$[/tex]
[tex]$1.4=\frac{0.25V}{v_f}+\frac{0.75V}{v_g}$[/tex]
[tex]$1.4=\frac{0.25V}{1.1565 \times 10^{-3}}+\frac{0.75V}{0.1274}$[/tex] (taking the value of [tex]$v_g$[/tex] and [tex]$v_g$[/tex] at 200°C )
[tex]$V=6.304 \times 10^{-3}$[/tex]
Now quality of vapor
[tex]$x=\frac{m_g}{m}$[/tex]
[tex]$=3.377 \times 10^{-3}$[/tex]
Internal energy at state 1 can be found out by
[tex]$u_1=u_f+xu_{fg}$[/tex]
[tex]$=850.65+3.377\times10^{-3}\times 1744.65$[/tex]
= 856.54 kJ/kg
After heating with the resistor for 20 minutes, at state 2, the tank contains saturated water vapor [tex]$v_2=v_g \text { and }\ x=1$[/tex]
Tank is rigid, so volume of tank is constant.
[tex]$v_g=v_2=\frac{V}{m}$[/tex]
[tex]$v_g=\frac{6.304\times 10^{-3}}{1.4}$[/tex]
[tex]$v_g=4.502 \times 10^{-3} \ m^3 /kg$[/tex]
Now interpolate the value to get temperature at state 2 with specific volume value to get final temperature
[tex]$T_2=360+(374.14-360)\left(\frac{0.004502-0.006945}{0.003155-0.006945}\right)$[/tex]
= 369.11° C
Internal energy at state 2
[tex]$u_2=2154.9 \ kJ/kg$[/tex]
Now power rating of the resistor
[tex]$P=\frac{m(u_2-u_1)}{t}$[/tex]
[tex]$P=\frac{1.4(2154.9-856.54)}{20 \times 60}$[/tex]
= 1.51 kW
HELP ASAP I WILL GIVE YOU 40 POINT AND BRAINIEST
Answer:
first page answer is B
second page answer is D
Explanation:
!!ill give brainliest!
Explain why !
1) An object is dropped from the top of tower of hight 156.8m and at the same time another object is thrown vertically upward with the velocity of 77.1 m/s from the feetof tower,when and where the object meet
Answer:
The objects meet after 2.033722438s, at a height 136.5334679m from the ground.
Explanation:
Call the object being dropped A and the object being thrown B.
When the objects meet, the time ('t') for both objects will be equal, and the sum of their distances will be equal to 156.8m.
Figure out the distance for A in terms of time, t:
s = ut + (1/2)at²
= 0t +(1/2)(9.8)t²
=4.9t²
Figure out the distance for B in terms of time, t:
s = ut + (1/2)at²
=(77.1)t + (1/2)(-9.8)t²
=77.1t - 4.9t²
We now adding the distances gives us 156.8, so can write:
(4.9t²) + (77.1t - 4.9t²) = 156.8
77.1t = 156.8
∴ t = 2.033722438s
To find the distances, plug in this value for t:
For A: 4.9t² → 20.26653209m
For B: 77.1t - 4.9t² → 136.5334679m
The objects will meet 155.2 meters below the top of the tower after 15.7 seconds.
What is the height?The formula to calculate the time it takes for the object thrown upwards to return to the ground:
Time = 2 * Initial velocity / gravitational acceleration
Plugging in the values given in the question, you can calculate the time as follows:
Time = 2 * 77.1 m/s / 9.8 m/s^2 = 15.7 seconds
To determine when and where the objects meet, you can use the following formula to calculate the height of the object thrown upwards at any given time:
[tex]Height = Initial velocity * time - (1/2) * gravitational acceleration * time^2[/tex]
Plugging in the time calculated above and the initial velocity and gravitational acceleration given in the question, you can calculate the height of the object at the time it returns to the ground as follows:
Height = 77.1 m/s * 15.7 s - (1/2) * 9.8 m/s^2 * (15.7 s)^2 = -1.6 meters
This means that the object thrown upwards returns to the ground 1.6 meters below the point where it was launched. The object dropped from the top of the tower will also have fallen a distance of 156.8 meters in the same amount of time, so the two objects will meet at a point 156.8 meters - 1.6 meters = 155.2 meters below the top of the tower
Learn more about height, here:
https://brainly.com/question/29710719
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A system has both thermal energy and chemical potential energy. According
to the law of conservation of energy, which statement describes the total
energy of this system?
O A. It will decrease over time as chemical potential energy is
transformed into thermal energy.
B. It will decrease as thermal energy is transferred out of the system.
C. It will remain constant because the total amount of thermal energy
plus chemical potential energy stays the same.
OD. It will increase as thermal energy is created from chemical
potential energy
Answer:
C. It will remain constant because the total amount of thermal energy plus chemical potential energy stays the same.
Explanation:
According to the law of conservation of energy, the total energy of this system will remain constant because the total amount of thermal energy plus chemical potential energy stays the same.
The law of conservation of energy states that "energy is neither created nor destroyed in system but transformed from one form to another". Total energy in a system will always be conserved. It will remain constant.Gravitational potential energy is potential energy based on what?
a. temperature
b.height
c. length
d. volume
Answer:
Height
Explanation:
the more height the more gravitational energy
What is the speed in kilometers per hour of a 27.78m/s baseball pitch?
Answer:
I actually don't know
Explanation:
ok chillll
according to Newton's 1st law , an object without a net force ? What
Answer:
an object in motion stays in motion an object at rest stays in rest
Explanation:
a car starts from rest and accelerates to a speed of 30 m/s in a time of 3 seconds. the average acceleration of the car is
Answer:
10m/s²
Explanation:
v=u+at
30=0+a(3)
∴a=10m/s²
Answer:
10m/s^2. Just curious, what kind of car is it? Is it a lamborghini
Explanation:
A stone is thrown at an angle of 34.0° above the horizontal from the top edge of a cliff with an initial speed of 18.3 m/s. A stopwatch measures the stone's trajectory time from the top of the cliff to the bottom at 2.6 s. What is the height of the cliff?
Answer:
Explanation:
Using the formula for calculating the maximum height in projectile
H = u²sin²theta/2g
u is the initial velocity = 18.3m/s
g is the acceleration due to gravity = 9.8m/s²
theta = 34°
Substitute
H = u²sin²theta/2g
H = 18.3²(sin34)²/2(9.8)
H = 334.89(0.5592)²/19.62
H = 5.337m
Hence the height of the cliff is 5.337m
5,000 joules of thermal energy were applied to 1-kg aluminum bar. What was the temperature increase?
Answer:
ΔT = 4.9°C
Explanation:
The thermal energy of the bar can be given as follows:
Thermal Energy = mCΔT
where,
m = mass of bar = 1 kg
C = specific heat capacity of aluminum = 1020 J/kg.°C
ΔT = Change in Temperature = ?
Therefore,
5000 J = (1 kg)(1020 J/kg.°C)ΔT
ΔT = (5000 J)/(1020 J/°C)
ΔT = 4.9°C
40 POINTS!
A 2,200 kg SUV is traveling at 25 m/s. What is the magnitude of its momentum?
A. 55,000 kg·m/s
B. 550 kg·m/s
C. 2,200 kg·m/s
D. 88 kg·m/s
Answer:55,000 kg•m/s
Explanation:
Silver has a mass of 10.5 grams and a volume of 19.3 cm3. What is its density?
Answer:
The answer is 0.54 g/cm³Explanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
From the question we have
[tex]density = \frac{10.5}{19.3} \\ = 0.54404145...[/tex]
We have the final answer as
0.54 g/cm³Hope this helps you
A dog jumps 0.80 m to catch a treat. The dog's displacement vector is shown below.
Which diagram shows the vertical and horizontal components of the dog's displacement?
Choose 1 answer:
Answer:D
Explanation:
It was right o khan academy
A dog jumps 0.80 M to catch a treat. The dog's displacement vector is shown below.
Which diagram shows the vertical and horizontal components of the dog's displacement?
THE ANSWER IS IN THE ATTACHMENT!
Please help I will give brainliest
Answer:
ask questions that the findings bring up
Explanation:
hope this helps :)
Answer:
ask questions that the findings bring up
4. Describe the forces acting on a softball after it leaves the pitcher's hand. Ignore the effects of
air resistance.
Answer:
Drag, which is a force preventing the ball from going faster than it was thrown, this increases as velocity increases. Gravity, which Is pulling down on the ball.
Explanation:
Hand washing is important especially in this time of pandemic
What must follow the division of the nucleus to complete the process of binary fission
Answer:
Replication of the DNA must occur. Segregation of the "original" and its "replica" follow. Cytokinesis ends the cell division process. Whether the cell was eukaryotic or prokaryotic, these basic events must occur.
Which reaction is an acid-base neutralization reaction?
A. Mg + 2HCl → MgCl2 + H2
B. HCl + NaOH → NaCl2 + H2O
C. SiCl4 → Si2 + 2Cl2
D. N2 + 3H2 → 2NH3
Answer:
option B is correct
Explanation:
neutralization is the reaction between acid and base to produce water and salt therefore option B is correct
brainliest please help
show the resultant force
8n downwards
since downwards force is greater than upwards just minus
can a chemical change be undone?
Answer:
no
Explanation:
because it will bind together in the molecular level
What two factors are a part of thermohaline circulation
Answer:
These deep-ocean currents are driven by differences in the water's density, which is controlled by temperature (thermo) and salinity (haline). This process is known as thermohaline circulation.
Explanation:
I WILL GIVE BRAINLIEST!!!
The Earth's diameter at the equators is ____ its diameter at the poles.
equal to
less than
greater than
A horse gallops for 3.5 minutes around the raceing track. During this time it changes velocity from 543 min to 628 min. Calculate the acceleration of the horse during this 3.5min interval
Answer:
The acceleration of the horse during this time interval is 24.286 m/min²
Explanation:
Given;
initial velocity of the horse during the gallop, u = 543 m /min
final velocity of the horse during the gallop, v = 628 m /min
time of motion, t = 3.5 minutes
The acceleration of the horse is given by the change in velocity per change in time;
[tex]a = \frac{v-u}{t}\\\\a = \frac{628-543}{3.5}\\\\a = 24.286 \ m/min^2[/tex]
Therefore, the acceleration of the horse during this time interval is 24.286 m/min²
help pls!!! this is worth 30 points, can someone pls help even if u can only give a few answers it would be helpful.
Answer:
1. potential 2. kinetic 3. potential 4. kinetic 5. kinetic 6. kinetic 7. kinetic 8. kinetic. potential
Which best compares kinetic energy and temperature?
Answer:
^ correct
Explanation:
Option A on edge 2020
What is another name for an alpha particle? Include the atomic number and mass number
Answer:
Alpha particles are Helium nuclei consisting of 2 protons and two neutrons (mass number 4, atomic number 2, no electrons and so carry a 2+ charge).
Explanation:
What is air??????????????
Answer:
Air is what you breath in
what is an isoelectronic series
Answer:
A comparison of the dimensions of atom an ions that have the same number of electron but different nuclear charges is called isoelectronic series
Answer:
A comparison of the dimensions of atoms or ions that have the same number of electrons but different nuclear charges, called an isoelectronic series, shows a clear correlation between increasing nuclear charge and decreasing size
PLEASE HELP ME QUICKLY!!!!!!!!!!!!!!
Answer:
I think thats the correct answer
Explanation: