Answer:
- the power rating of the resistance heater is 24139.5 W
- the inner surface temperature of the pipe at the exit is 96.34°C
Explanation:
Given the data in the question;
Flow rate of water in the tube V" = 5L/min = 8.333 × 10⁻⁵ m³/s
The water is to be heated from 10°C to 80°C;
so Average or mean temperature [tex]T_{avg[/tex] will be;
[tex]T_{avg[/tex] = (T₁ + T₂) / 2 = (10 + 80) / 2 = 90/2 = 45°C
Now, from the Table " Properties of Water " at average temperature;
at [tex]T_{avg[/tex] = 45°C
density p = 990.1 kg/m³
specific heat [tex]C_p[/tex] = 4180 J/kg-k
thermal conductivity k = 0.637 W/m-°C
Now, we determine the mass flow;
m" = pV"
we substitute
m" = 990.1 × 8.333 × 10⁻⁵
m" = 0.08250 kg/s
we know that the power rating of the resistance heater is equal to the heat transfer rate to the water;
Q' = m"[tex]C_p[/tex]( T₂ - T₁ )
we substitute
Q' = (0.08250 × 4180 ) ( 80 - 10 )
Q' = 344.85 × 70
Q' = 24139.5 W
Hence, the power rating of the resistance heater is 24139.5 W
Next, we determine the average velocity of water in the tube;
[tex]V_{avg[/tex] = V" / [tex]A_c[/tex]
[tex]V_{avg[/tex] = V" / ( [tex]\frac{1}{4}[/tex]πD² )
given that; flows through a 2-cm-internal-diameter; D = 0.02 m
we substitute
[tex]V_{avg[/tex] = (8.333 × 10⁻⁵) / ( [tex]\frac{1}{4}[/tex]π × (0.02)² )
[tex]V_{avg[/tex] = (8.333 × 10⁻⁵) / ( 3.14159 × 10⁻⁴ )
[tex]V_{avg[/tex] = 0.265 m/s
Also, from table " saturated water property table "
At 45°C
viscosity μ = 0.596 × 10⁻³ kg/m-s
Prandtl number Pr = 3.91
Now, we determine the kinematic viscosity
v = μ / p
we substitute
v = ( 0.596 × 10⁻³ ) / 990.1
v = 6.01959 × 10⁻⁷ m²/s
so, Reynolds number in the flow region will be;
Re = ([tex]V_{avg[/tex] × D) / v
we substitute
Re = ( 0.265 × 0.02) / (6.01959 × 10⁻⁷)
Re = 8804.586
we can see that our Reynolds number ( 8804.586 ) more than 2300 and less than 10,000.
Hydraulic and thermal entry length are equal in this flow region,
such that;
[tex]L_h[/tex] = [tex]L_t[/tex]
⇒ 10 × D = 10 × 0.02 = 0.2 m
we can see that the entry length ( 0.2 m ) is smaller than the given length ( 13 m ) in the question; the flow is a turbulent flow.
So we the Nuddelt number
Nu = [tex]0.023Re^{0.8} Pr^{0.4[/tex]
Nu = 0.023 × [tex]8804.586^{0.8[/tex] × [tex]3.91^{0.4[/tex]
Nu = 56.8
Hence, the heat transfer coefficient h will be;
h = [tex]\frac{k}{D}[/tex] × Nu
we substitute
h = [tex]\frac{0.637}{0.02}[/tex] × 56.8
h = 31.85 × 56.8
h = 1809.1 W/m²-°C
Now, area of the heat transfer will be
A[tex]_s[/tex] = πDL
we substitute
A[tex]_s[/tex] = π × 0.02 × 13
A[tex]_s[/tex] = 0.8168 m²
Finally we determine the inner temperature of the pipe at exit. using the relation;
Q' = hA[tex]_s[/tex]( T₃ - T₂ )
we substitute
24139.5 = 1809.1 × 0.8168( T₃ - 10 )
24139.5 = 1477.67288( T₃ - 80 )
24139.5 = 1477.67288T₃ - 118213.8304
24139.5 + 118213.8304 = 1477.67288T₃
1477.67288T₃ = 142353.3304
T₃ = 142353.3304 / 1477.67288T
T₃ = 96.34°C
Therefore, the inner surface temperature of the pipe at the exit is 96.34°C
If a 75 W lightbulb is 15% efficient, how many joules of light energy does the bulb produce every minute?
Answer:
11.25J
Explanation:
15=(output/75)x100
output =(75x15)/100=11.25J
Visible light falls into wavelength ranges of 400-700 nm, for which 1 m = 1 × 10 9 nm . The energy and wavelength of light are related by the equation E = h c λ where E is energy in Joules, h is Planck's constant ( 6.626 × 10 − 34 J-s ), c is the speed of light ( 2.998 × 10 8 m/s ), and λ is the wavelength in m. If a visible light photon has a wavelength of 560.6 nm, what is the energy of the photon (in J)?
Given the wavelength of the visible light photon, the energy of the photon is 3.54 × 10⁻¹⁹J
Given the data in the question;
Wavelength of visible light; [tex]\lambda = 560.6 nm = 5.606*10^{-7}m[/tex]
Speed of light; [tex]c = 2.998 * 10^8 m/s[/tex]
Planck's constant; [tex]h = 6.626 * 10^{-34} J.s[/tex]
The energy and wavelength of light are related by the equation:
[tex]E = \frac{hc}{\lambda}[/tex]
Where E is energy of photon in Joules, h is Planck's constant, c is the speed of light and λ is the wavelength,
We substitute our given value into the equation
[tex]E = \frac{(6.626*10^{-34}J.s)(2.998*10^8m/s)}{5.606*10^{-7}m} \\\\E = \frac{(1.986*10^{-25}J.m}{5.606*10^{-7}m}\\\\E = 3.54 * 10^{-19}J[/tex]
Therefore, given the wavelength of the visible light photon, the energy of the photon is 3.54 × 10⁻¹⁹J
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A sound wave travels with a velocity of 330 m/s and has a frequency of 500 Hz. What is its
wavelength?
Answer:
Wavelength = 0.66 meters
Explanation:
Given the following data;
Speed = 330 m/s
Frequency = 500 Hz
To find the wavelength;
Mathematically, wavelength is calculated using this formula;
[tex] Wavelength = \frac {speed}{frequency} [/tex]
Substituting into the equation, we have;
[tex] Wavelength = \frac {330}{500} [/tex]
Wavelength = 0.66 meters
4. A car is moving at 10m/s when it begins to accelerate to 2.5m/s. (a). How
long does it take to reach a 25m/s?
62.5 m/s
Explanation:
An ampere is measured in
Seconds
Hours
Answer:
Seconds
Explanation:
Hope it helps you in your learning process.
The rate of flow of charge (per second) through a conductor is called electric current.
S. I unit of electric current is Ampere (named after French Physicist Andre Marie Ampere)
The speed of a wave is 40 m/s. If the wavelength is 80 centimeters, what is the frequency of the wave?
SOLVE IT COMPLETELY
The speed of a wave is 40 m/s. If the wavelength is 80 centimeters, what is the frequency of the wave ?
Answer:-Given:-Velocity (V) = 40 m/s
Wavelength [tex] (\lambda) [/tex] = 80 cm = 0.8 m
To Find:-The frequency (F) of the wave.
Solution:-We know,
[tex] \bf V \: = \: F \: × \: \lambda [/tex]
40 = F × 0.8
F = [tex] \frac{40}{0.8} [/tex]
F = 50
The frequency of the wave is 50 Hz. [Answer]Which object had the greatest average speed?
A
B
C
D
1pt The process by which rock minerals are changed by natural processes into new substances is known as:
O A. erosion.
O B. chemical weathering.
O C. sedimentation.
O D. mechanical weathering.
The process by which rock minerals are changed by natural processes into new substances is known as chemical weathering. Option A is correct.
What is weathering?The breakdown or dissolution of rocks and minerals on the Earth's surface is referred to as weathering.
Weathering is the erosion or disintegration of rocks, building materials, etc., induced by chemical interactions dissolved in it rather than by mechanical processes.
Water, ice, acids, salts, plants, animals, and temperature variations are all weathering agents.
Chemical weathering is the process by which rock minerals are transformed into new compounds by natural processes.
Hence, option A is correct.
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Calculate the average speed of blood flow in the major arteries of the body, which have a total cross-section area of about 2.0cm^2.
Answer:
0.9m/s
?
Explanation:
Someone please help and I will mark you as Brainlist! No
2) Translation kinetic energy is defined as the energy of a system due to the motion of the system’s...
• center of mass
• axis of symmetry
• molecules
• rotational movement
3) the work- energy theorem states that
• when work is done on a system, no energy changes can occur.
• when work is done on a system, a change in energy occurs.
• when energy is released by a system, work can be done.
• when work is done by a system, energy is released
Answer:
2) center mass
3) when work is done by a system, energy is released
Explanation:
Groups of organs that work together to complete a series of takes are called:
A: Skeletal System
B: Organ System
C: Muscular System
A group of organs working together comprises an organ system, B.
simplify. (x+2)(x-1)-2(x+1)
Answer: x²-x-4
Explanation:
Here, we are going to use the FOIL method to simplify.
FirstOuter Inner Last--------------------------------------------------------------------------------------
Given
(x+2)(x-1)-2(x+1)
Expand parenthesis
= x²-x+2x-2-2x-2
Put like terms together
= x²-(x-2x+2x)-(2+2)
Combine like terms
= x²-x-4
Hope this helps!! :)
Please let me know if you have any questions
Answer:
x² - x - 4
Explanation:
Multiply the parentheses
x² - x + 2x - 2 - 2 (x + 1)
Distribute -2 through the parentheses
- 2 (x + 1)
Since two opposites add up to zero, remove them from the expression
x² - x - 2 - 2
Calculate the difference
x² - x - 4
why do substance takes long to condense than freezing?
A person, with his ear to the ground, sees a huge stone strike the concrete pavement. A moment later two sounds are heard from the impact: one travels in the air and the other in the concrete, and they are 0.70 ss apart. The speed of sound in air is 343 m/sm/s, and in concrete is 3000 m/sm/s. Part A How far away did the impact occur
Answer:
271.095 m
Explanation:
✓ Let speed of sound in air that was given as (343 m/s) be represented as (Vi)
✓( speed of sound in concrete that was given as (3000 m/s ) be debited as (Vc)
✓ Let the distance travelled by the sound = s
✓duration of Time that exist between heard of sounds = 0.70s
But we know that
Time = (Distance / Speed)
✓Time it takes the sound to travel through air= s/vi = s/343
✓Time it takes the sound to travel through concrete= s/vc = s/3000
✓ (s/343) - (s/3000) = 0.70
Finding LCM and simplify
[(3000s - 343s)]/1029000 = 0.70
2657s /1029000 = 0.70
Making " s" subject of the formula
s= (1029000 × 0.70)/2657
s=720300/ 2657
s= 271.095 m
Hence, The impact took place at a distance of 271.095 m away from the person.
A 2.5 V battery is connected to a small light
bulb with a resistance of 4.8 Ω .
What is the current in the bulb?
Answer in units of A.
Answer: I=0.52 A
Explanation:
Given
Voltage is [tex]2.5\ V[/tex]
Resistance [tex]R=4.8\ \Omega[/tex]
Current is given by
[tex]I=\dfrac{V}{R}[/tex]
[tex]\Rightarrow I=\dfrac{2.5}{4.8}=0.52\ A[/tex]
Explain What's make up macromolecules?
Answer:
Atoms
Explanation:
Atoms make up everything
An astrophysicist mounts two thin lenses along a single optical axis (the lenses are at right angles to the line connecting them, and they appear concentric when viewed from either end). The lenses are identical, each with a positive (converging) focal length of 15.2 cm. They are separated by a distance of 40.2 cm. Lens 1 is to the left of Lens 2. In order to evaluate the lens combination as a single optical instrument, the teacher places an object 30.0 cm in front of (to the left of) Lens 1.
Required:
a. What is the final image's distance (in cm) from Lens 2? (Omit any sign that may result from your calculation.)
b. Where is the final image located?
c. What is the overall magnification of the lens pair, considered as a single optical instrument?
Answer:
1 / i + 1 / o = 1 / f thin lens equations
i = o f / (o - f) rearranging
Lens 1: object = 30 cm f = 15.2 cm
i1 = 30 * 15.2 / (30 - 15.2) = 30.8 cm
o2 = 40.2 - 30/8 = 9.4 cm distance of image 1 from lens 2
i2 = 9.4 * 15.2 / (9.4 - 15.2) = - 24.6 cm
The final image is 24.6 cm to the left of lens 2
The first image is inverted
The second image is erect (as seen from the first image)
So the final image is inverted
M = m1 * m2 = (-30.8 / 30) * (24.6 / 9.4) = -2.69
It can be deduced that the final image's distance from Lens 2 will be 30.8 cm.
How to calculate the distanceBy using the Lens formula, the distance will be calculated thus:
1/v + 1/u = 1/15.2
1/v + 1/30.0 = 1/15.2
v = 30.8cm
In this case, the image formed will be to the right.
Lastly, the overall magnification of the lens pair will be:
M = (30.8/30.0)[(-28.4/40.7 - 30.8)]
M = -2.94.
In conclusion, the magnification is -2.94.
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A sinusoidal electromagnetic wave is propagating in a vacuum in the z-direction. Part A If at a particular instant and at a certain point in space the electric field is in the x-direction and has a magnitude of 4.70 V/mV/m, what is the magnitude of the magnetic field of the wave at this same point in space and instant in time
Answer:
the magnitude of the magnetic field is 1.23 × 10⁻⁸ T { in the +y direction }
Explanation:
Given the data in the question;
the relation between the electric field and the magnetic field in an electromagnetic wave can be written as follows;
c = E₀/B₀
where c is speed of light, E₀ is the amplitude of the electric field and B₀ is the amplitude of the magnetic field.
given that; E₀ = 4.70 V/m, we know that; speed of light c = 3 × 10⁸ m/s
so from our relation; c = E₀/B₀
B₀ = E₀/c
we substitute
B₀ = 4.70 / 3 × 10⁸
B₀ = 1.23 × 10⁻⁸ T { in the +y direction }
Therefore, the magnitude of the magnetic field is 1.23 × 10⁻⁸ T { in the +y direction }
A 16 Ω resistor and a 6 Ω resistor are connected in series to an ideal 6 V battery.
Find the current in each resistor.
Answer in units of A.
b) Find the potential difference across the first
resistor.
Answer in units of V.
c) Find the potential difference across the second
resistor.
Answer in units of V
Answer:
(a) 0.273 A
(b) 4.368 V
(c) 1.638 V
Explanation:
From the question,
(a) Applying ohm's law
V = IR'...................... Equation 1
Where V = Voltage of the battery, I = Current in each of the resistor, R' = Total resistance of the combined resistors
Since the Two resisstors are connected in series,
(i) The same current flows through both resistors
(ii) The total resistor (R') = R₁+R₂
Therefore,
V = (R₁+R₂)I
Make I the subject of the equation
I = V/(R₁+R₂)................. Equation 2
Given: V = 6 V, R₁ = 16 Ω, R₂ = 6 Ω
Substitute into equation 2
I = 6/(16+6)
I = 6/22
I = 0.273 A
(b) The potential difference across the first resisto
V₁ = IR₁...................... Equation 3
Given: I = 0.273 A, R₁ = 16 Ω
Substitute these values into equation 3
V₁ = 0.273(16)
V₁ = 4.368 V
(c) The Potential difference across the second resistor is
V₂ = IR₂.................... Equation 4
V₂ = 0.273×6
V₂ = 1.638 V
Write a paragraph descibing three rides in an amusement park and how rides cause you
to move.
Answer:
Hope this helps! can I have brainliest im trying to level up.
Explanation:
Bumper cars are a great place to see Sir Isaac Newton’s three laws of motion in action. Here’s how:
Newton’s First Law: Every object in motion continues in motion and every object at rest continues to be at rest unless an outside force acts upon it.
This is because all objects have inertia – the property of matter that resists changes to the object’s motion.
Newton found that if a ball is sitting on a table, it will stay sitting there because that is what it ‘wants’ to do.
If the ball is set in motion, it will keep traveling in a straight path because, again, that is what it ‘wants’ to do.
An object in motion will not stop, slow down, or change its direction unless an outside force acts on it (such as gravity, friction, and air resistance).
When you are riding in a bumper car and end up in a collision with another bumper car, you feel a jolt. This is because your body’s inertia wants it to keep traveling in the direction it was moving with the car even though your bumper car has now suddenly stopped.
Newton’s Second Law: The greater the mass of an object, the harder it is to change its speed.
(More force is needed to move it.)
You already know this law and practice it in your everyday life. Something that is small, such as a pebble, is much easier to pick up and throw than something that is large and heavy, such as a boulder.
When riding in the bumper cars, you may have noticed that people who weigh less tend to get pushed around more than people who weigh more.
The more mass (weight) an object has, the more force it takes to move it.
And since all the bumper cars usually have the same top velocity, the cars carrying more mass will never travel as far as the cars carrying less mass after a collision.
Newton’s Third Law: For every action, there is an equal and opposite reaction.
If two bumper cars traveling at the same speed and carrying the same amount of weight run into each other, they will bounce off and move an equal distance away from each other.
And based on the second law, if there is a difference in the amount of weight being carried in the two cars, the car with less weight will travel farther away from the point of impact than the car carrying more weight.
Spring is a time when animals reproduce. What might you see a heron do? Build a nest A. Grow feathers A. Hibernate Migrate
Answer:
A. Build a nest.
Explanation:
It wont do any of the other things and they need a place to sleep and lay eggs plus it is a bird
The heron birds belong to Ardeidae family. Some of the species among them are referred to as egrets or bitterns rather than a heron. A heron bird build a nest during Spring. The correct option is A.
What is Heron bird?The heron is known as a long-legged, long-necked, fresh water and coastal birds. It a medium to large size bird with long necks and legs. They exhibit sexual dimorphism in size. The two male and female sex of the same species show distinct attributes beyond their difference in sexual organs.
Almost all the heron species are found in water and they are essentially non-swimming water birds which feed on the margins of lakes, ponds, sea, rivers and swamps. The small species of heron are generally referred to as the dwarf bittern.
The nesting season indicates the time of year during which birds build nests and lay eggs in them. In most cases bring up their young. It is in the spring season lot of food are available.
Thus the correct option is A.
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An object is placed at one of the two focal points of a thin converging lens. Where will its image form?
A. the other focal point of the lens
B. in the middle of the lens
C. an infinite distance from the lens
D. the same position as the object
Answer:
C. an infinite distance from the lens
Explanation:
There are five distinct cases of image formation in a convex lens depending upon the position of an object:
1. When the object is placed at an infinite distance from the lens, its real image is formed at the focal point.
2. When the object is placed before the center of curvature of the lens, its real image is formed between the center of curvature and the focal point.
3. When the object is placed at the center of curvature of the lens, its real image is formed at the center of curvature.
4. When the object is placed between the center of curvature and the focal length of the lens, its real image is formed behind the center of curvature.
5. When the object is placed at the focal point of the lens, its virtual image is formed at infinity.
Hence, from point 5 the answer is:
C. an infinite distance from the lens
A 50 W light bulb is plugged into a standard
110 V outlet.
a) How much does it cost per month (31
days) to leave the light turned on? Assume
electric energy cost of 3.39 cents/kW · h.
Answer in units of dollars
b) What is the resistance of the bulb?
c) What is the current in the bulb?
Answer in units of mA
Answer:
$1.26
Explanation:
Power =energy/ time
energy =powerxtime
energy =50x31x24=37200
=37.2kwh
1kwh =3.39
37.2kwh=3.39x37.2=126.108cent
=$1.26
What is the wavelength associated with 0.113kg ball traveling with velocity of 43 m/s?
Answer:
Wavelength = [tex]1.36\times 10^{-34}\ m[/tex]
Explanation:
Given that,
The mass of a ball, m = 0.113 kg
Velocity of the ball, v = 43 m/s
We need to find the wavelength of the ball. It can be calculated by applying the De-Broglie concept. So,
[tex]\lambda=\dfrac{h}{mv}[/tex]
Put all the values,
[tex]\lambda=\dfrac{6.63\times 10^{-34}}{0.113\times 43}\\\\=1.36\times 10^{-34}\ m[/tex]
So, the wavelength of the ball is equal to [tex]1.36\times 10^{-34}\ m[/tex].
What is the speed of a 1.57 N bullet traveling with a total momentum equal to 131 Kg.m/s?
Answer:
https://web.njit.edu/~binchen/phys111/LectureNotes/Physics111_lecture08.pdf
Explanation:it's 38 slides so look at the more bottom ones and there will be your question and answer
Al, Bo, Cy, Di, Ed, and Fred assumed different positions in the room as shown in the image below. Their reflections are marked in red with the apostrophe.
Check all the reflections Ed can see
Answer:
A<L BO DI ED
Explanation:
3.9. How long will a boy sitting near the window of a train travelling at 36km/h see a train passing by in the opposite direction with a speed of 18km/h. The length of the slow-moving train is 90 m.
Answer:
please give me brainlist and follow
Explanation:
Given:
The speed of the train ,which the boy is observing(t) = 18 km/hr
[ Now , to convert km/hr into m/s we have to multiply by 5/18 ]
So,
speed of the observed train = 18× 5/18
☞ 05 m/s
Also, The speed of the train in which the boy is sitting is(s) = 36 km/hr
Speed in m/s will be = 36 × 5/18
☞ 10 m/s
Also, The Length of the Train = 90m
Therefore:.
The speed of the train is given (expressed) by
= > speed \: = \frac{distance}{time}=>speed=
time
distance
= > time \: = \frac{distance}{Velocity }=>time=
Velocity
distance
Where,
velocity = Realtive velocity of both trains
Distance = Length of the train
So, The above mentioned formulae can also be written as :
= > time = \frac{length}{relative \: velocity}=>time=
relativevelocity
length
Here,
Relative velocity will be :
☞. s -(-t)
☞. 10 -(-5)
☞.15 m/s = Relative velocity
Now , Finally putting the values in the formulae respectively
■ Time = 90/15
■ Time = 6 sec [Answer]
a. Draw four rays parallel to the optical axis of your mirror. Two above the optic axis and two below it.
b. Trace the rays all the way to the surface of the spherical cap.
c. Draw a normal to the surface of the mirror at each of the four points where the rays touch the mirror.
Answer:
f = q
Explanation:
In the attachment we can see a diagram of the parallel rays.
The dotted line represents the normal to the mirror surface
These rays when reflected using the constructor equation
[tex]\frac{1}{f} = \frac{1}{p} + \frac{1}{q}[/tex]
where p and q are the distance to the object and the image respectively.
Since the rays are parallel P = inf
1 / f = 1 / inf + 1 / q
f = q
this means that all the rays focus on one focal point.
Research DNA phenotyping and make a list of pros and cons. What are its possible advantages? What might go wrong? Would it change investigations for the better, or create unfair bias? Think about how this technology would impact forensics, law enforcement, and the public in general. List at least three arguments for and three arguments against it. (1 sentence/phrase each)
Answer:
Pros of DNA phenotyping:
-Phenotypical characteristics can be predicted such as eye color, hair color, skin pigmentation, and many more.
-predict ancestry of an organism
-Use to find criminals
Cons of DNA phenotyping:
-Some phenotypical traits could not be predicted
- Invading privacy
This technology will surely help forensics, law enforcement as it helps track down unknown perpetrators of crime.
3 arguments for it:
- accurate in narrow down researches
- finding biological ancestry
3 arguments against it
It violates the privacy policy of an individual
Racial discrimination is done of public
Equality policies are not followed by it.
II) Write meanings and frame sentences of the following words
1) loftily
2) dispute
3) diverged
4) jostle
5) souvenirs
6) coveted
Answer:
Explanation:
1. loftily - To do something in an arrogant manner.
He answered her in a loftily manner.
2) dispute - This is an argument or a disagreement.
There is a dispute between the friends.
3) diverged - To move in a different direction or separate from others.
The road diverged here to my town.
4) jostle - To come in contact, push, or collide with someone in a crowd .
The boy jostled his way through the crowd.
5) souvenirs - Something kept ad a reminder or taken as a memory of something or someone.
Before his dad died, he gave James his watch as a souvenir.
6) coveted - Something or someone that's greatly envied or desired.
James always covered power but didn't eventually get it.