Explanation:
Acceleration is final velocity minus initial velocity divided by time.
a = (v − u) / t
a = (27 m/s − 5 m/s) / 10 s
a = 2.2 m/s²
Which of the following is an example of a properly written testable hypothesis? *
A people should taste this new health food and see whether it makes them stronger
B When dog owners don't feed their puppies Brand A food, the puppies do not grow properly
C If Frederico had added the leaves to the compost pile last year, he wouldn't have to organic fertilizer
D if it is dark, then an owl will find a mouse by the sound the mouse makes
Answer:
D. if it is dark, then an owl will find a mouse by the sound the mouse makes
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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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.
energy
Potential energy + Kinetic energy
OA) Heat
OB) Chemical
Electrical
OD) Mechanical
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:
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
To solve more questions on Mass and weight, visit the link below-
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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.
3. An earthquake measures 3 on Richterscale:
(i)Would it be recorded by a seismograph ?
(ii)ls it likely to cause much damage ?
Answer:
Yes, it would be recorded by a seismograph. The earthquake with magnitude of 3 on Richter Scale is not likely to cause much damageThe boundary between areas of high and low pressure:
A Front
B Barometer
C Weather
D Air pressure
Help please and explain elaborately thanks in advanced
Answer:
So overall, motion and interference of matter are needed equally for friction, which is held together by the force of gravity. Without gravity, everything would have fly away in the universe, and the friction would not have exist. Hence, friction is dependent on gravity.
Elaborately means in a detailed and carefully arranged manner.
Explanation:
hope this helps!!!!
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)
Which action describes the first step in both scientific investigation and technological design?
researching how solar panels work
identifying a need for a solar panel
communicating to the team that solar panels are easy to install
designing a solution by sketching a prototype for a solar panel
Answer:
The best answer would be D
Explanation:
This would be best because if you sketch about an object or thing you are making it can help you better picture what you are making or someone else therefore the answer is D
Answer:
Answer is D fs
Explanation:
*designing a solution by sketching a prototype for a solar panel*
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
[04.05] An atom has an atomic number of 12 and a mass number of 25. How many neutrons does the atom have?
Answer: is 13
Explanation:
A recipe for a casserole calls for 1 cup of milk. If a chef currently has 0.5 gallons of milk, how many casseroles can the chef make?
Answer:
The chef can make 8 casseroles
Explanation:
Units Conversion
We need to recall 1 gallon = 16 US cups.
A casserole needs 1 cup of milk, and the chef has 0.5 gallons of milk. Those 0.5 gallons are equivalent to 0.5*16 = 8 cups, thus the chef can make 8 casseroles.
A 8 g of iron shot is added to a graduated cylinder containing 46 mL of water. The water level rises to the 49 mL mark, from this information, calculate the density of iron
Answer:
The answer is 2.67 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\[/tex]
From the question
mass of iron = 8 g
volume = final volume of water - initial volume of water
volume = 49 - 46 = 3 mL
We have
[tex]density = \frac{8}{3} \\ = 2.666666...[/tex]
We have the final answer as
2.67 g/mLHope this helps you
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 anther and filament are parts of a flower's:
stamen
petal
pistil
stigma
A ninja applies a force of 1250-N to a piece of 4-inch solid oak with his fist. What is the size of
the force applied to the fist by the piece of oak?
Answer:
The force is 1250-N
Explanation:
Generally according to Newtons third law , which states that for every action there is an equal and opposite reaction
Now considering the question, the action here is the force applied by the ninja while the reaction is the force applied by the oak and from Newton law both of these action are equal but opposite to each other.
Hence the force applied by the the piece of oak on the fist is 1250 N
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?
non examples of kinetic energy
Answer:
Anything that isn't moving
How does changing the force affect the sound?
Answer:
From a sound standpoint, higher tracking force reduces all other things being equal which might reduce the top end a bit and increase bass.
What's the time it takes a car to attain the speed of 30 m/s when accelerating from rest at 2 m/s (squared)
A- 15 s
B- 2 s
C- 60 s
D- 30 s
E- none
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.
Learn more about Newton's second law here, refer to the link;
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Give me an example of heterogeneous mixture
Answer:
oil and water
Explanation:
A force of 6.0 N is applied horizontally to a 3.0 kg crate initially at rest on a horizontal frictionless surface. After the crate is pushed for 1.5 seconds, it has a gelocity of 3.0 m/s. Does this support Newton’s second law of motion, that force equals mass times acceleration?
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:
I need help because I don’t understand that question
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)
who has a iphone (age range 15-19 )
Hi friend! I have an iPhone. why do you ask????