Answer:
Reasd through the explanartion first :)
Explanation:
Initial velocity, u = 30 m/s
Final velocity, v = 100 m/s
Acceleration, a = 40 m/s²
Distance traveled, s = ?
According to the 3rd equation of motion,
We know that,
v² - u² = 2as
So, putting all the values, we get
⇒ v² - u² = 2as
⇒ (100)² - (30)² = 2 × 40 × s
⇒ 10000 - 900 = 80s
⇒ 9100 = 80s
⇒ 9100/80 = s
⇒ s = 113.75 m.
Where does the focal point of a convex mirror fall?
a. In front of the mirror.
b. Behind the curvature of the mirror.
C. At the vertex.
d. None of the above.
The heat loss from a boiler is to be held at a maximum of 900Btu/h ft2 of wall area. What thickness of asbestos (k= 0.10 Btu/h ft ℉) is required if the inner and outer surfaces of the insulation are to be 1600 and 500℉, respectively? Now if a 3-in.-thick layer of kaolin brick (k= 0.07 Btu/h ft ℉) is added to the outside of the asbestos, what heat flux will be result if the outside surface of the kaolin is 250℉? What will be the temperature at the interface between the asbestos and kaolin for this condition?
Answer:
a. 0.122 ft b. -70 Btu/h ft² c. 633.33 °F
Explanation:
a. Since the rate of heat loss dQ/dt = kAΔT/d where k = thermal conductivity, A = area, ΔT = temperature gradient and d = thickness of insulation.
Now [dQ/dt]/A = kΔT/d
Given that [dQ/dt]/A = rate of heat loss per unit area = -900Btu/h ft², k = 0.10 Btu/h ft ℉(for asbestos), ΔT = T₂ - T₁ = 500 °F - 1600 °F = -1100 °F. We need to find the thickness of asbestos, d. So,
d = kΔT/[dQ/dt]/A
d = 0.10 Btu/h ft ℉ × -1100 °F/-900Btu/h ft²
d = 0.122 ft
b. If the 3 in thick Kaolin is added to the outside of the asbestos, and the outside temperature of the asbestos is 250℉, the heat loss due to the Kaolin is thus
[dQ/dt]/A = k'ΔT'/d'
k' = 0.07 Btu/h ft ℉(for Kaolin), ΔT' = T₂ - T₁ = 250 °F - 500 °F = -250 °F and d' = 3 in = 3/12 ft = 0.25 ft
[dQ/dt]/A = 0.07 Btu/h ft ℉ × -250 °F/0.25 ft
[dQ/dt]/A = -70 Btu/h ft²
c. To find the temperature at the interface, the total heat flux equals the individual heat loss from the asbestos and kaolin. So
[dQ/dt]/A = k(T₂ - T₁)/d + k'(T₃ - T₂)/d' where [dQ/dt]/A = -900Btu/h ft², k = 0.10 Btu/h ft ℉(for asbestos), k' = 0.07 Btu/h ft ℉(for Kaolin), T₁ = 1600 °F, T₂ = unknown and T₃ = 250℉.
Substituting these values into the equation, we have
-900Btu/h ft² = 0.10 Btu/h ft ℉(T₂ - 1600 °F)/0.122 ft + 0.07 Btu/h ft ℉(250℉ - T₂)/0.25 ft
-900Btu/h ft² = 0.82 Btu/h ft ℉(T₂ - 1600 °F) + 0.28Btu/h ft ℉(250℉ - T₂)
-900 °F = 0.82(T₂ - 1600 °F) + 0.28(250℉ - T₂)
-900 °F = 0.82T₂ - 1312°F + 70 °F - 0.28T₂
collecting like terms, we have
-900 °F + 1312°F - 70 °F = 0.82T₂ - 0.28T₂
342 °F = 0.54T₂
Dividing both sides by 0.54, we have
T₂ = 342 °F/0.54
T₂ = 633.33 °F
The thickness of asbestos required is 0.122 ft.
The heat flux will be -70 Btu/h ft²
And the temperature of the interface is 633.33 °F.
(i) the rate of heat loss :
dQ/dt = kAΔT/d
where k = thermal conductivity, A = area, ΔT = temperature gradient, and
d = thickness of insulation.
[dQ/dt]/A = kΔT/d
Given that [dQ/dt]/A = rate of heat loss per unit area = -900Btu/h ft²,
k = 0.10 Btu/h ft ℉,
ΔT = 500 °F - 1600 °F = -1100 °F
We have to find the thickness of asbestos that is d.
d = kΔT/[dQ/dt]/A
d = 0.10 Btu/h ft ℉ × -1100 °F/-900Btu/h ft²
d = 0.122 ft is the thickness required.
(ii) a 3-in thick Kaolin is added to the outside of the asbestos
outside temperature of the asbestos is 250℉,
the heat loss due to the Kaolin is:
[dQ/dt]/A = k'ΔT'/d'
k' = 0.07 Btu/h ft ℉(for Kaolin), ΔT' = T₂ - T₁ = 250 °F - 500 °F = -250 °F and d' = 3 in = 3/12 ft = 0.25 ft
[dQ/dt]/A = 0.07 Btu/h ft ℉ × -250 °F/0.25 ft
[dQ/dt]/A = -70 Btu/h ft²
(iii) temperature at the interface
the total heat flux :
[dQ/dt]/A = k(T₂ - T₁)/d + k'(T₃ - T₂)/d'
where [dQ/dt]/A = -900 Btu/h ft²,
k = 0.10 Btu/h ft ℉ (for asbestos),
k' = 0.07 Btu/h ft ℉ (for Kaolin),
T₁ = 1600 °F and T₃ = 250℉.
-900 = 0.10(T₂ - 1600 °F)/0.122 + 0.07(250℉ - T₂)/0.25
-900 = 0.82(T₂ - 1600 °F) + 0.28(250℉ - T₂)
-900 °F = 0.82(T₂ - 1600 °F) + 0.28(250℉ - T₂)
-900 °F = 0.82T₂ - 1312°F + 70 °F - 0.28T₂
-900 °F + 1312°F - 70 °F = 0.82T₂ - 0.28T₂
342 °F = 0.54T₂
Dividing both sides by 0.54, we have
T₂ = 342 °F/0.54
T₂ = 633.33 °F
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Round the following answer to the correct number of
significant figures. 25.657 + 134.24 = ? *
Answer:
I'm pretty sure its 160, correct me if I am wrong
Explanation:
Answer:
ya it is 160
Explanation:
the original answer is 159.897 so if u round it to 3 Sig u get 160
who has a iphone (age range 15-19 )
Hi friend! I have an iPhone. why do you ask????
how long would it take for a car to travel 200 km if it has an average speed of 55 km/hr?
Answer:
3.6
Explanation:
Answer:
3.64 hrs
Explanation:
Whats the difference between a solar eclipse and a lunar eclipse?
Answer:
A solar eclipse results when the moon passes in between the earth and the sun hiding the sun fully or partly for some time. A lunar eclipse occurs when the earth passes in between the moon and the sun casting its shadow on the moon and thus hiding it fully or partly for some time.
Explanation:
your welcome
You are designing an apparatus to shoot a water balloon through a 3rd story window (25m above the ground)
Answer:
The balloon needs a vertical velocity of approximately 22.14 m/s to reach the window
Explanation:
The given parameters are;
The destination of the designed water balloon we shoot = The 3rd story window
The height of the 3rd story window which the water balloon should reach = 25 m
Therefore, we have, the equation of motion of the water balloon given as follows;
v² = u² - 2 × g × s
Where;
[tex]u_y[/tex] = The initial vertical velocity of the balloon
[tex]v_y[/tex] = The final vertical velocity of the balloon = 0 m/s
g = The acceleration due to gravity = 9.8 m/s
s = The height the balloon is intended reach at the final velocity becomes 0 m/s = The height of the 3rd story window
∴ s = 25 m
Substituting the values, we have;
0² = [tex]u_y[/tex]² - 2 × 9.8 × 25
[tex]u_y[/tex]² = 2 × 9.8 × 25 = 490
[tex]u_y[/tex] = √490 = 7·√10
The initial vertical velocity of the balloon = [tex]u_y[/tex] = 7·√10 m/s
Therefore, the balloon needs a vertical velocity of 7·√10 m/s which is approximately 22.14 m/s to reach the window.
Jack took up the job of a front desk staff at a reputed hotel. He will be interacting with various customers and employees from different parts of the world. What should his manager do to help Jack adapt to a diverse workplace? The manager is quite impressed with Jack. He wants to encourage Jack to actively listen and explore all solutions. He also wants to train Jack to avoid using I-statements and encourage him to participate in programs that teach him more about his own ethnic group. In addition, the manager wants to help Jack to understand the customs of other cultures.
Answer:
a. He wants to encourage Jack to actively listen and explore all solutions.
d. the manager wants to help Jack to understand the customs of other cultures.
Explanation:
As a front desk staff of the hotet, jack has to learn to activel listen, and explore all solutions available within his reach when deali with customers.
Because he is the first point of contact in the hotel as the front desk officer, this means he would get to interact with people of diverse cultures, customs e.t.c. Jack needs to learn and understand this cultures.
write any three rules two keep in in mind while using SI units
Answer:
Rules and conventions for writing SI units and their symbols
The units named after scientists are not written with a capital initial letter. ...
The symbols of the units named after scientist should be written by a capital letter. ...
Small letters are used as symbols for units not derived from a proper name
Explanation:
Hope this helps u
Crown me as brainliest:)
Answer:
when temperature is expressed in Kelvin,the degree sign is omitted.
only accepted symbols should be used.
some space is always to be left between the number and the symbol of the unit and also between the symbols for compound units such as force,momentum, etc.
a spring balance used to weigh candy is built with a spring the spring stretches 3.00 cm when a 15 n weight is placed in the pan. when the weight is replaced with 3 kg of candy, what distance will the spring stretch?
a.7.0 b.4.5 c.3.8 d.5.9
Answer: 5.9cm
Explanation:
15N/3cm=5
Convert 3kg to N (29.42N)
Use the 5 from earlier to divide 29.42/5=5.884
Round to 5.9
5.9cm is the answer
(I don’t know if I solved this the correct way but I got it right. 5.9 is the correct answer)
A marble accelerates from rest at a constant rate .it travels 36 m in 12.0 sec what’s is it’s final velocity and what was the acceleration
Answer:
a = 0.50 m/s²
v = 6.0 m/s
Explanation:
Step 1: Given data
Initial velocity (u): 0 m/s (rest)Displacement of the marble (s): 36 mTime elapsed (t): 12.0 sFinal velocity (v): ?Acceleration (a): ?Step 2: Calculate the acceleration
We will use the following suvat equation.
s = u × t + 1/2 × a × t²
s = 0 × 12.0 s + 1/2 × a × (12.0 s)²
36 m = a × 72.0 s²
a = 0.50 m/s²
Step 3: Calculate the final velocity
We will use the following suvat equation.
v = u + a × t
v = 0 + 0.50 m/s² × 12.0 s
v = 6.0 m/s
define engineering in your own words
Answer:
engeenering
Explanation:
how you design or do something with tools or with hand
In february a little town received snow on a daily basis. The first day they had 10 inches, 3 inches the second, 7 inches the 3rd, and 4 inches on the fourth day. What was the average snowfall?
Answer:
The average is 6
Explanation:
To find the average, you have to first add all the numbers. After you add all the numbers up, then you divide by how many numbers there are. This one had 4 numbers so you divide by 4
The average snowfall of the four days was 6 inches.
What is snow?
When atmospheric water vapor freeze into small ice crystals and falling in small white flakes or lying on the ground as a white layer, it is called snow.
In the question it is said that,
Amount of snow received by the town on first day = 10 inches.
Amount of snow received by the town on second day = 3 inches.
Amount of snow received by the town on third day = 7 inches.
Amount of snow received by the town on fourth day = 4 inches.
Total amount of snow received by the town on these four days = ( 10 + 3+ 7 + 4) inches.
=24 inches.
Hence, average amount of snow received by the town on these four days = total amount of snow received ÷ 4
= ( 24 ÷ 4) inches.
= 6 inches.
Hence, the average snow received by the little town was 6 inches on those days.
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Two children fight over a toy. One pulls with a force of 8N to the right. The other pulls with
a force of 6N to the left. What is the strength and direction of the net force on the toy?
Answer: To the right
Explanation:
8n is more strength then 6n periodt pooh ✨
When two children fight over a toy. One pulls with a force of 8N to the right. The other pulls with a force of 6N to the left then the net force on the toy would be 2 N to the right.
What is Newton's second law?Newton's Second Law states that The resultant force acting on an object is proportional to the rate of change of momentum.
The mathematical expression for Newton's second law is as follows
F = ma
As given in the problem, two children fight over a toy. One pulls with a force of 8N to the right. The other pulls with a force of 6N to the left.
Net force = 8 - 6
= 2 Newtons
Thus, the net force of the toy comes out to be 2 Newtons.
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Why is thermal energy classified as kinetic energy?
Answer:
Thermal energy is an example of kinetic energy, as it is due to the motion of particles, with motion being the key. Thermal energy results in an object or a system having a temperature that can be measured. Thermal energy can be transferred from one object or system to another in the form of heat.
Explanation:
Answer:
Thermal energy is an example of kinetic energy, as it is due to the motion of particles, with motion being the key. Thermal energy results in an object or a system having a temperature that can be measured. Thermal energy can be transferred from one object or system to another in the form of heat.
Explanation:
What was the instantaneous speed of Bear A at 5 seconds in meters/min? (No unit conversions necessary, no units required for answer).
Answer:
Answer: The answer is 40.
Explanation: There is a typo, they mean 5 minutes. Five minutes is the line between zero and 10, and the dot matches up at 5 and 200. 200 divided by 5= 40.
(i got this answer from: https://brainly.com/question/18253554)
What state of matter has the highest energy? Lowest?
Answer:
The highest state of matter in energy is gas. The lowest is solid.
Explanation:
The reason why is because gas is the highest conductor of electricity (which is why we have lightning). However, solids don't conduct electricity very well.
Hydrogen is found as a gas on Earth but exists in all four states in the solar
system. Four samples of hydrogen have equal masses but are each in a
different state. Which statement about the relative amounts of thermal
energy in the samples is true?
Answer: the sample of solid has less energy than the sample of gas
Explanation:
APEX
if your mass is 72kg your textbooks in Madison has 3.7 kg and you and your textbook are separated by a distance of 0.33 M what is the gravitational force between you and your textbook
Answer:
1.63 X 10^-7N
Explanation:
Give me an example of heterogeneous mixture
Answer:
oil and water
Explanation:
Which of the following statements is accurate when considering the role of cognition in shaping behavior? A. Cognition helps determine if a consequence is influential enough to control behavior. B. Cognition will most likely decrease the chance for classical conditioning to work. C. One’s cognitive processes are irrelevant when it comes to shaping behavior. D. One’s cognitive processes only work in shaping behavior when a particular consequence is desired. Please select the best answer from the choices provided A B C D
Answer: the answer is A.
Explanation:
brainliest please?
Answer:
A.
Cognition helps determine if a consequence is influential enough to control behavior.
Explanation:
This is right on edg. 2020
What happens to particle spacing when temperature increase, What we call this process?
Answer:
The atoms start vibrating really fast, making the space between them larger. It's an increase in Kinetic Energy.
The reverse of the process of sublimation is called
a freezing.
b vaporization.
c deposition.
d condensation.
Science
Using the graphs on your notes, how are wavelength and frequency related to sound waves? Make sure to use proper terminology in your response.
A delivery drone uniformly slowed down from 45 m/s to 23 m/s in a straight line over a 30-minute duration within a 16-kilometer radius of its warehouse. What was the magnitude of its average acceleration?
A. 1.2 x 10^−2 m/s^2
B. 5.3 x 10^−1 m/s^2
C. 7.3 x 10^−1m/s^2
D. 4.4 x 10^1 m/s^2
Pregunta 2
George took his puppy to a dog park and unleashed her once they entered the gate. The puppy accelerated Northward, from rest, to 15 meters per second in 10
seconds. What was China's displacement in this time interval?
How does an object become negatively charged
Explanation:
When insulating materials rub against each other, they may become electrically charged . Electrons , which are negatively charged, may be 'rubbed off' one material and on to the other. The material that gains electrons becomes negatively charged. The material that loses electrons is left with a positive charge.
The speed of an object undergoing constant acceleration increases from 8.0 m/s to 12.0 m/s in 10.0 seconds. How far does the object travel during the
10.0 seconds?
4 m
100 m
800 m
10 m
Answer:
is the question finnished
Explanation:
What is the weight of a 328N emperor penguin?
Answer:
Weight = 3217.68
Explanation:
N times Gravity = weight
Gravity= 9.81
The weight of the emperor penguin whose mass is 328 Kg on is 3214.4 Newtons.
What is Weight ?
Weight is the force exerted by the earth on an object at the surface of the earth. Mathematically -
W = m x g
where -
[m] is the mass of object
[g] is acceleration due to gravity
Given is the mass of an emperor penguin as 328 Kg.
We can write -
Mass [m] = 328 kg
Acceleration due to gravity [g] = 9.8 m/s²
Therefore, the weight of the emperor penguin will be
W[P] = m x g = 328 x 9.8 = 3214.4 Newtons
Hence, the weight of the emperor penguin whose mass is 328 Kg on is 3214.4 Newtons
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Which answer explains why plate B is moving underneath plate A
A. Plate B is more dense than plate A because it is composed of oceanic crust
B. Plate A is more dense than plate B because it is composed of oceanic crust
C. plate B is more dense than plate A because it is composed of continental crust
D. Plate A is more dense than plate B because it is composed of continental crust
Answer:
A.
Explanation:
Earth is composed of different layers and one layer moves over another due to differences in the densities.
According to the physics of density, a substance having less density floats over a higher density substance. The oceanic crust has more density than the continental crust that is why continental crust float over oceanic crust.
So in the given example, plate B is moving below the plate A, it means plate B is more dense than plate A because plate B is composed of oceanic crust . For example : continents float over the asthenosphere (a layer below the lithosphere).
Hence, the correct answer is "A ".