I have a really long assignment I don't understand! please help
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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 NEEDED ASAP I'M GIVING BRAINLIEST
1) Select the best answer from the choices below. Light has many properties of waves, but sometimes it also behaves like:
a
A photon
b
Polarized light
c
Ultraviolet rays
d
A stream of particles
2) What type of waves transmit signals in satellite communication?
a
Microwaves
b
X-rays
c
Gamma Rays
d
Radio Waves
3) Cell phones use digital signals to send and receive information. These digital signals travel as what kind of wave?
a
Gamma rays
b
X-rays
c
Microwaves
d
Radio waves
Answer:
1.
d . A stream of particles
2. D. Radiowave
3. Microwaves
Answer:
1.
d . A stream of particles
2. D. Radiowave
3. Microwaves
Explanation:
How do the individual forces compare when the rider experiences a sensation being lighter than his normal weight ? What is the acceleration direction when this occurs ?
Answer:
When the elevator is accelerating downward, the person feels lighter due to the downward normal force being less than the person's weight.
Explanation:
A person riding in an elevator subjected to a series of unbalanced forces depending on the direction the elevator is travelling.
Two forces are acting on the person; the force of gravity and the upward normal force from the elevator.
When the elevator is going upwards with acceleration a, the person feels heavier than his normal weight, due to the upward normal force being greater than the person's weight. N = mg + ma
When the elevator is moving downwards with acceleration a, the person feels lighter due to the downward normal force being less than the person's weight. N = mg - ma
However, when the elevator is moving up or down at constant velocity ie. acceleration a = 0, the person experience a normal force equal to weight. N = mg
When the elevator is moving downwards with acceleration a = g, the person experiences weightlessness. N = (mg - mg) = 0
Is Time and Light both connected in anyway?
Answer:
It is not connected by any way
A 58-kg boy swings a baseball bat, which causes a 0.140-kg baseball to move toward 3rd base with a velocity of 38.0 m/s.
Calculate the kinetic energy of the baseball (rounding your answer to the integer).
Answer:
101 J
Explanation:
Answer:
[tex]\boxed {\boxed {\sf 101 \ Joules}}[/tex]
Explanation:
Kinetic energy can be found using the following formula:
[tex]KE=\frac{1}{2}mv^2[/tex]
The mass of the baseball is 0.140 kilograms and the velocity is 38.0 meters per second.
[tex]m= 0.140 \ kg \\v= 38.0 \ m/s[/tex]
Substitute the values into the formula.
[tex]KE=\frac{1}{2} [0.140 \ kg][(38.0 \ m/s)^2][/tex]
First, evaluate the exponent.
(38.0 m/s)²= 38.0 m/s * 38.0 m/s = 1444 m²/s²[tex]KE=\frac{1}{2}(0.140 \ kg)(1444 \ m^2/s^2)[/tex]
Multiply the two numbers in parentheses together.
[tex]KE=\frac{1}{2}(202.16 \ kg*m^2/s^2)[/tex]
Multiply the fraction by the number, or divide the number by 2.
[tex]KE=101.08 \ kg*m^2/s^2[/tex]
Round to the nearest whole number. The 0 in the tenth place tells us we can leave the number as is.
[tex]KE\approx 101 \ kg*m^2/s^2[/tex]
1 kg*m²/s² is equal to 1 Joule. Therefore, our answer of 101 kg*m²/s² is equal to 101 Joules (J).
[tex]KE\approx 101 \ J[/tex]
The kinetic energy of the baseball is about 101 Joules.
What is the Net Force acting
on the box below?
PLS HELP THIS IS DUE IN TWO HOURS
Answer:
C
Explanation:
1. Some penguins are playing turtle hockey on the frictionless ice. Ramona the penguin hits the turtle
with a force of magnitude F, and the turtle experiences an acceleration of magnitude a (Fand a are of
unknown size). Francisco the penguin hits the same turtle with a force of magnitude three times
greater than Ramona's force (3F). What will the resulting acceleration of the turtle be? Answer in
terms of a. Support your answer with reasoning and reference to Newton's Second Law.
Answer:
a' = 3a
Explanation:
Newton's Second Law gives the magnitude of the unbalanced force applied to an object as follows:
F = ma
where,
F = Force Applied
m = Mass of Object
a = acceleration
FOR RAMONA'S PUSH:
F = F
m = m
a = a
Therefore,
F = ma
a = F/m ---------------- equation (1)
FOR FRANSICO'S PUSH:
F = 3F
m = m (mass of turtle will be same)
a = a'
Therefore,
3F = ma'
a' = 3F/m
using equation 1
a' = 3a
What happens to the minerals as gneiss forms from schist?
Answer:
Explanation:
Gneiss is a high grade metamorphic rock, meaning that it has been subjected to higher temperatures and pressures than schist. However, unlike slate and schist, gneiss does not preferentially break along planes of foliation because less than 50% of the minerals formed during the metamorphism are aligned in thin layers.
Which part of a DC generator keeps the electric current flowing in only one
direction?
A. The permanent magnets
B. The commutator
o
C. The power source
D. The wire coil
Which of the following is a characteristic of a base?
A. pH greater than 7
B. pH between 4 and 13
C. pH between 4 and 9
D. pH less than 7
Answer:
A. pH greater than 7
Explanation:
Because a base has a pH scale of 8 to 14