Complete question is;
Annealing is a process by which steel is reheated and then cooled to make it less brittle. Consider the reheat stage for a 100 mm thick plate (ρ = 7830 kg/m³, Cp = 550 J/Kg.K, k = 48 W/m K). The plate initially is at 200 °C and is to be heated to a minimum temperature of 550 °C. Heating is effected in a gas-fired furnace where the products of combustion at T∞ = 800 °C maintain a convection heat transfer coefficient of h = 250 W/m.K on both surfaces of the plate. How long should the plate be left in the furnace?
Answer:
860 seconds
Explanation:
We are given;
Initial Temperature; T_i = 200 °C
Minimum Temperature; T_o = 550 °C
T∞ = 800 °C
convection coefficient; h = 250 W/m².K
ρ = 7830 kg/m³
Cp = 550 J/kg K
k = 48 W/m K
Plate thickness = 100mm
Thus,L = 100/2 = 50mm = 0.05 m
Let's find the biot number from the formula;
Bi = hL/K
Bi = (250 × 0.05)/48
Bi = 0.2604
Now, lowest temperature in the slab is given as;
θ_o = (T_o - T∞)/(T_i - T∞)
θ_o = (550 - 800)/(200 - 800)
θ_o = 0.4167
Now, from online tables calculation, we can find the root of the biot number.
Thus, root of the biot number Bi = 0.2604 is;
ζ1 = 0.488 rad
Also, C1 is gotten as 1.0396
Now,formula for thermal diffusivity is;
α = k/ρc
α = 48/(7830 × 550)
α = 1.115 × 10^(-5) m²/s
Also, from online tables, f(ζ1) = 0.401
Thus, we can find the time the plate should the plate be left in the furnace from;
-(ζ1)²(αt/L²) = In 0.401
-(ζ1)²(αt/L²) = -0.9138
t = (-0.9138 × 0.05²)/-(0.488² × 1.115 × 10^(-5))
t ≈ 860 s
Does any form of movement generate thermal energy?
Atoms, molecules, and ions are the smallest particles that make up all matter. These microscopic particles are always in motion, either colliding or oscillating back and forth. Heat (or thermal) energy is created by the motion of particles and is found in all matter. As a result, thermal energy may be defined as an object's ability to perform work as a result of particle movement. Thermal energy is a form of kinetic energy, which is the energy associated with motion, because it is generated by the movement of particles.
a person is able to walk 18 miles in 3 hours. what is that person’s speed? show your work.
Answer:
6 mph
Explanation:
18 divided by 3 equals 6. The person walks 6 miles per hour.
In a novel from 1866 the author describes a spaceship that is blasted out of a cannon with a speed of about 11.000 m/s. The spaceship is approximately 274 m long but part of it is packed with gunpowder, so it accelerates over a distance of only 213 m. What was the acceleration (in m/s2) experienced by the occupants of the spaceship during the launch?
Answer:
[tex]a=0.284\ m/s^2[/tex]
Explanation:
Given that,
Initially, the spaceship was at rest, u = 0
Final velocity of the spaceship, v = 11 m/s
Distance accelerated by the spaceship, d = 213 m
We need to find the acceleration experienced by the occupants of the spaceship during the launch. It is a concept based on the equation of kinematics. Using the third equation of motion to find acceleration.
[tex]v^2-u^2=2ad\\\\a=\dfrac{v^2-u^2}{2d}\\\\a=\dfrac{(11)^2-(0)^2}{2\times 213}\\\\a=0.284\ m/s^2[/tex]
So, the acceleration experienced by the occupants of the spaceship is [tex]0.284\ m/s^2[/tex].
What effect did the virus have on Frank initially in the movie Osmosis Jones
Answer: But with that germ-ridden egg comes a mortal danger: Osmosis discovers Frank has really contracted a villainous and black-hearted deadly virus known as Thrax who arrives and is plotting to ultimately overheat Frank's body, killing him from the inside out!
i can predict the motion of objects based on newton’s laws because ________
Answer;
Newton's laws models the motion of a body perfectly well.
The knowledge of the force acting on a body gives a good grasp of the resulting motion.
There are three know laws of motion postulated by Newton;
1st law; it states that an object will remain in its state of rest or uniform motion unless if it is acted upon by an external force.
2nd law: it states that the acceleration of a body depends on the mass and force acting on it.
3rd law: it states that action and reaction are equal and opposite.
A sound understanding of these law's can help predict and model the motion of a body .
Benny has 20 jellybeans and wants to share with his friends how many will each friend get? there are 5 friends.
Answer each friend will get 3.33333 repeating if he is included. if only his friends are getting them then each one gets 4
Explanation:
devide 20/6 and 20/5 respectively.
Answer:
Yes ma’am I’m not doing it ok I’m sorry I didn’t mean to kitty you didn’t know that I was just trying to kitty kitty mama mama daddy mama mama I don’t wanna talk about it anymore I’m not gonna be mad I just got kicked out of the house I just woke me down and I’m sorry for the time you got snap I just got kicked out of the house I just woke me a text
Explanation:
Which is NOT a fossil fuel?
A)Coal
B)Oil
C)Wood
D)Natural gas
Answer:
wood because, Coal, oil and natural gas are examples of natural gas. Biogas is the mixture of gases produced by the breakdown of organic matter in the absence of oxygen, usually consisting of certain quantities of methane and other constituents. therefore wood is not a fossil fuel
The magnetic field 0.02 m from a wire is 0.1 t. what is the magnitude of the magnetic field 0.01 m from the same wire? 0.01 t 0.05 t 0.1 t 0.2 t
The magnitude of the magnetic field is 0.01 m from the same wire will be 0.2 T.It is the type of domain where the magnetic force is received.
What is a magnetic field?It is the type of field where the magnetic force is obtained. With the help of a magnetic field. The magnetic force is obtained it is the field felt around a moving electric charge.
The given data in the problem is;
r is the radius= 0.02 m
I is the current = 10,000A
x is the position considered = 0.002 m
The value of the electric current is found as;
[tex]\rm B= \frac{\mu_0 Ix }{2 \pi r} \\\\ \rm I= \frac{B \times 2\pi r}{\mu_0} \\\\ \rm I= \frac{0.1 \times 2\times 3.14 \times 0.02}{4 \pi \times 10^{-7}} \\\\ \rm I= 10,000 \ A[/tex]
The megnetic field through the wire will be;
[tex]\rm B= \frac{\mu_0 I}{2 \pi r} \\\\\rm B= \frac{4 \pi \times 10^{-7} \times 10,000}{2 \times 3.14 \times 0.01} \\\\ \rm B= 0.2 \ T[/tex]
Hence the value of the megnetic field will be 0.2 T.
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Answer:
D
Explanation:
If a boy does 150 J of work every 10 seconds that he pulls a wagon, how much power is he producing?
1,500 W
150 W
10 W
15 W
Answer:
15 W
Explanation:
Answer:
15 W
Explanation:
why does a balloon bursts if too much of air is blown into it
Answer:
it is due to the elastic rubber and the air pressure builds up and the rubber expands
A turtle moves at a speed of 1.0 km/h. How fast is the turtle
moving in meters per second (m/s)?
Answer:
0.28 m/s
Explanation:
1.0km/h * (1000m / 1km) * (1h / 3600s) =
The speed of the turtle in meters per second is 0.28.
What is unit conversion?Multiplication or division by a numerical factor, selection of the correct number of significant figures, and unit conversion are all steps in a multi-step procedure.
Speed is defined as the ratio of the time distance traveled by the body to the time taken by the body to cover the distance. The speed is a scalar quantity and does not require any direction to represent it.
Given that the speed of the turtle is 1.0 km/h. The speed in meters per hour will be calculated as below:-
To calculate the speed in meters per second multiply the number by 1000 and divide it by 3600.
1.0 km/h. = 1 x 1000 / ( 3600 )
1.0 km/h. = 1000 / ( 3600 )
1.0 km/h. = 0.28 meter second.
Therefore, the speed of the turtle in meters per second is 0.28.
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Which statement describes dynamic equilibrium?
Answer:An object has balanced forces acting on it and constant velocity.
Explanation:
If 360 Joules of work are needed to move a crate a distance of 4 meters in 5 sec, what is the power used
Answer:
72watts
Explanation:
360/5
=72watts
State Newton's Law of cooling
[tex] \\ \\ [/tex]
(⚆﹏⚆) xD
Answer:
the rate at which an object cools is proportional to the difference in temperature between the object and the object's surroundings.
To state Newton's Law of cooling we say "According to Newton's law of cooling, the speed at which an item cools is proportional to the temperature differential between the object and its surroundings.".
What is Newton's Law of cooling?Generally, According to Newton's law of cooling, the speed at which an item cools is proportional to the temperature differential between the object and its surroundings.
In conclusion, Newton's Law of cooling applies to the temperature interaction of an object and its environment.
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state and explain the structure of ear?
Answer:
The ear has external, middle, and inner portions. The outer ear is called the pinna and is made of ridged cartilage covered by skin. Sound funnels through the pinna into the external auditory canal, a short tube that ends at the eardrum (tympanic membrane).
The function of the outer ear is to collect sound waves and guide them to the tympanic membrane. The middle ear is a narrow air-filled cavity in the temporal bone. It is spanned by a chain of three tiny bones—the malleus (hammer), incus (anvil), and stapes (stirrup), collectively called the auditory ossicles.
the diagram shows a stationery box sitting on the floor which statement about the other force is exerted on the box are true
Susan and Joe push a table 18 meters down a hall by exerting a force of 200
newtons What is the total amount of work done on the table
Answer:
50
Explanation:
prove that f=ma where the symbols have their usual meaning.
Explanation:
According to Newton's second law of motion:
Force is directly proportional to
Change of momentum/time taken
Change of momentum= mv-mu
where m is mass, u is initial velocity and v is final velocity. so,
F∝mv-mu/t
F∝m(v-u)/t
F∝ma (a=v-u/t)
F=kma where k is a constant
In SI units the value of k will become one so the equation will be:
F=ma
What is the mass of a 37.0 N
weight?
m
=
= [ ? ] kg
Answer: 3.775 KG
Explanation: W = 37 N
m = ?
AS WE KNOW THAT
W = mG
37 = m 9.8
m = 37/9.8
m = 3.775 KG
Action and reaction forces are described by which of Newton's laws of motion?
first
second
third
fourth
Answer:
Newtons Third Law
Explanation:
Please give me brainliest much appreciated
Answer:
3rd
Explanation:
How are gravity and air resistance the same?
Answer:
because baconeggandcheese
Explanation:
peepa pug
Suppose you are spinning a child around in a circle by her arms. The
radius of her orbit around you is 2 meter. Her speed is 5 m/s. Her mass
is 20 kg. What is the magnitude and direction of tension in her arms?
Answer: 25
Explanation ;)
A car travels 10 meters east in 4 seconds. What is the car's velocity? *
Answer:
your velocity is 2.5 m/sec
What is the total displacement of the object? Please explain why/show your work
Answer: TOTAL DISPLACEmENT = 312.5 m
Explanation: BY USING FORmULA OF AREA OF TRIANGLE
TOTAL DISPLACEmENT = 1/2 BASE X ALTITUDE
= 1/2 (25-0)(35-10)
= 1/2 (25)(25)
= 625/2
= 312.5 m
Hello people ~
1 hertz is equal to
(a) 1 vibration per minute
(b) 10 vibrations per minute
(c) 60 vibrations per minute
(d) 600 vibrations per minute
60vibrations per minute
Usually 1 hertz equals to 1 vibration per second
1 min=60sTotal vibration=60
So option C is correct
Please someone help me plz I don’t understand 1 or 2 plz help me plz plz plz
Answer: 1.Magnification and resolution are important because the magnification in larges the image and the resolution makes it move shape and detailed creating the perfect image. 2. i dont know the second one, sorry
Explanation:
An image is formed 16 cm behind a convex lens whose focal length is 8 cm. Using the Lens Equation, determine the position of the object.
For an image formed 16 cm behind a convex lens whose focal length is 8 cm, the position of the object is mathematically given as
o=16cm
What is the position of the object.?Question Parameter(s):
An image is formed 16 cm behind a convex lens
focal length is 8 cm
Generally, the equation for the is mathematically given as
1/f=1/o+1/i
Therefore
1/8=1/o+1/16
o=16cm
In conclusion, the position is
o=16cm
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Picturing the way a volcano erupts to remember how a volcano functions is called a. visualizing c. keywording b. categorizing d. all of these please select the best answer from the choices provided a b c d
Answer:
A.
Explanation:
You need to imagine how the volcano erupts to know how the volcano works.
Tim rides at an average speed of 8 mph (mile per hour). How long does it take
for him to ride 44 miles h (show process)
Answer: 5.5 hours
Explanation: 44/8=5.5.
Answer:
5.5 Hours at 8mph to go 44 miles
Explanation:
d=s/t
t=s/d
44/8 = 5.5 time it took 5.5 hours it will take him to ride 44 miles
Bats, which have a high-calorie diet of insects and face little danger from predators, sleep a lot. In contrast, cows, which have a low-calorie diet and are at risk from
predators, sleep loss. What function of sleep theory do these differences support?
a. Sleep enhances immune function.
b. Sleep repairs and restores.
Oc Sleep conserves and protects.
Od. Sleep enhances learning and memory.
yers
The function of sleep theory supported by the illustration is sleep conserves and protects.
Positive impact of sleep
From the first sentence, bats sleep a lot because they face little danger from predators and as such, they have a high-calorie diet of insects.
Negative impact of sleepFrom the second sentence, cows sleep less, because they face more danger from predators and as such, they have a low-calorie diet of insects.
We can conclude that sleep helps to keep animal safe. Therefore, the correct option will be, "Sleep conserves and protects".
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