Answer:
The thermal conductivity [tex]k = 1.4094 W/ m\cdot K[/tex]
Explanation:
From the question we are told that
The depth of the thermocouple from the surface is x = 10 mm = 0.01 m
The temperature is [tex]T_f = 100 ^o C[/tex]
The initial temperature is [tex]T_i = 30 ^o C[/tex]
The temperature of the thermocouple after t = 2 minutes( 2 * 60 = 120 \ seconds) is [tex]T_t = 65 ^o C[/tex]
The density of the material is [tex]\rho = 2200 kg/m^3[/tex]
The specific heat of the solid [tex]c_s = 700 J/kg \cdot K[/tex]
Generally the equation for semi -infinite medium is mathematically as
[tex]\frac{T_s - T }{T_i - T} = erf [\frac{x}{2 \sqrt{\alpha * t} } ][/tex]
[tex]\frac{65 - 100 }{30 - 100} = erf [\frac{x}{2 \sqrt{\alpha * t} } ][/tex]
[tex]0.5 = erf [\frac{0.01}{2 \sqrt{\alpha * 120} } ][/tex]
Here [tex]\alpha[/tex] is a constant with unit [tex]m^2 /s[/tex]
[tex]\frac{0.01}{ 2 (\sqrt{\alpha * 120 } )}[/tex] this is from the Gaussian function table
[tex]0.0 1 = 0.954 * (\sqrt{\alpha * 120 } )[/tex]
=> [tex]\sqrt{\alpha * 120 } = \frac{0.01 }{0.954 }[/tex]
=> [tex]\alpha = 9.1525 *10^{-7} \ m^2 /s[/tex]
Generally the thermal conductivity is mathematically represented as
[tex]k = \alpha * \rho * c_s[/tex]
[tex]k = 9.1525 *10^{-7} * 2200 * 700[/tex]
[tex]k = 1.4094 W/ m\cdot K[/tex]
write .00000023 in scientific notation
Answer: 2.3 x 10^-7
Explanation:
When you move the decimal to the right, you decrease the exponent. So lets count how many spots you have to move the decimal spot to get an answer between 1 and 10. I counted seven spots.
So:
[tex]2.3 *10^-^7[/tex]
2.3 * 10 °−7
The degree indicates that the number is that small thing that floats above
A 2.60-kg box is sliding across the horizontal floor of an elevator. The coefficient of kinetic friction between the box and the floor is 0.380. Determine the kinetic frictional force that acts on the box for each of the following cases. (a) The elevator is stationary. N (b) The elevator is accelerating upward with an acceleration whose magnitude is 1.20 m/s2. N (c) The elevator is accelerating downward with an acceleration whose magnitude is 1.20 m/s2. N Additional Materials
Answer:
a) F = 9.69 N
b) F = 10.88 N
c) F = 8.51 N
Explanation:
a) The kinetic frictional force when the elevator is stationary is the following:
[tex] F_{k} = \mu_{k}N = \mu(mg) [/tex]
Where:
F(k) is the kinetic frictional force
N is the normal force = mg
m: is the mass = 2.60 kg
g: is the gravity = 9.81 m/s²
μ(k) is the coefficient of kinetic friction = 0.380
[tex] F_{k} = \mu(mg) = 0.380*2.60 kg*9.81 m/s^{2} = 9.69 N [/tex]
b) When the elevator is accelerating upward with acceleration "a" equal to 1.20 m/s²
[tex] F_{k} = \mu_{k}N = \mu[m(g + a)] [/tex]
The normal is equal to mg plus ma because the elevator is accelerating upward
[tex] F_{k} = \mu m(g + a) = 0.380*2.60 kg(9.81 m/s^{2} + 1.20 m/s^{2}) = 10.88 N [/tex]
c) When the elevator is accelerating downward with a =1.20 m/s² we can find the kinetic frictional force similar to the previous case:
[tex] F_{k} = \mu m(g - a) = 0.380*2.60 kg(9.81 m/s^{2} - 1.20 m/s^{2}) = 8.51 N [/tex]
I hope it helps you!
If a bird applies a 5 N upward force on a branch to lift the branch of ground to a
height of 24 m, how much work did the bird do?
Explain period motion of oscillatory body.
Answer:
motion repeating itself is referred to as periodic or oscillatory motion. An object in such motion oscillates about an equilibrium position due to a restoring force or torque. ... This motion is important to study many phenomena including electromagnetic waves, alternating current circuits, and molecules.
Explanation:
Answer:
Moves to and from about it's mean position in a fixed time interval.
Francesco, a pizza chef preparing the dough for your pizza is throwing it to expand it. In this process, you notice that a chunk of it comes off, flying separately from the rest and on to the floor. If Francesco is 6 feet and 3 inches tall, and the chunk flies off vertically straight up from this height at a speed of 1 m/s, with what speed does the chunk hit the ground?
Answer:
6.12 m/s
Explanation:
In order to solve this we have two parts of this problem, first we have the time that the pizza dough spent going upwards and after that we have a free fall from there, so we will use the free fall formula after we figured out whats the final height the dough reached after being thrown from Francesco's height which is 6ft3inches or 1.90 meters
We first have to find out how much time the dough spent in the air before reaching 0 as final speed and then started the free falling:
The formula would be:
[tex]Vf=Vo-at\\0=1-(-9.81t)\\1=9.81t\\t=\frac{1}{9.81}\\t=.101[/tex]
The formula to find out final height would be:
[tex]y = \frac{ h + Vy (t-gt^{2})}{2} \\[/tex]
Now we just insert the values we know
[tex]y = h+ \frac{ Vy (t-gt^{2})}{2} \\\\y = 1.90 +\frac{ .101-(-9.81)(.101)^{2})}{2} \\\\y=1.91[/tex]
So from 1.91 meteres the free fal started we have to just calculate the final velocity with the formula for free fall and velocity:
[tex](vf)^{2} =Vo^2 +2ad[/tex]
Since Vo is 0 because we are talking about free falling we just insert the values we know:
[tex](vf)^{2} =Vo^2 +2ad\\(vf)^{2} =2ad\\(vf)^{2} =2(9.81)(1.91)\\vf=\sqrt{37.4742} \\Vf=6.12m/s[/tex]
So the final speed that the dough hit the ground with is 6.12 m/s
If the efficiency of a machine is equal to 85% and the work input is 10.0 , what is the work output?
Answer:
8.5
Explanation:
to find efficiency take the ratio between the output and input
85/100=output/input
Julie takes a cold glass of dear, doness houd out the register and pusi on the babe hathewwad warme up to room temperature, Julie sees buthles of gas form in the und and me to the face Which conclusion is best supported by Jules onervations? The liquid is a pure sutrance because it is closers O The liquid is a mixture because its temperature res The liquid is a pure substance because it remains lowd when The liquid is a mixture because it has a gas dissolved in a loud
Answer:
D. The liquid is a mixture because it has a gas dissolved in a liquid.
Two velocity vectors, one is twice of the other, and separated by 90 Degree angle. If their resultant is calculated 90 m/s, what the magnitude of bigger vector?
Answer:
Vy = 80.5 [m/s]
Explanation:
In order to solve this problem we must use the Pythagorean theorem.
V = 90 [m/s]
The components are Vx and Vy:
Therefore:
[tex]v=\sqrt{v_{x}^{2} + v_{y}^{2} }[/tex]
where:
Vy = 2*Vx ; because one is twice of the other.
[tex]90 = \sqrt{v_{x}^{2} +(2*v_{x})^{2} }\\ 90 =\sqrt{v_{x}^{2}+4*v_{x}^{2}} \\90 =\sqrt{5v_{x}^{2}} \\90=2.23*v_{x} \\v_{x}=40.25[m/s][/tex]
and the bigger vector is:
Vy = 40.25*2
Vy = 80.5 [m/s]
An automobile accelerates from rest 5.0m/s ever second. How far does it travel after 3.0 s
Answer:
30 m
Explanation:
Two asteroides crashed. The crash caused both asteroids to change speed.Scientist wants to use the change in speed and motion to figure out which asteroide has more mass.Based on the information in the diagram which statement is correct ? In your answer explain ,explain what the forces were like and why the asteroids changed in motion
Astroid one has less asked her to. Able to use enough force to not only change or keep it self go in the same direction.
(a) If the initial speed both asteroids before collision is the same, then the asteroid with greater mass will have more momentum before collision while the asteroid with lesser mass will have greater momentum after collision.
(b) The force of the impact depends of the velocity change and time of collision of the asteroids.
According to the principle of conservation of linear momentum, the sum of the momentum of each asteroid before collision must equal the sum of their momentum after collision.
[tex]m_1 u_1 + m_2 u_2 = m_1v_1 + m_2 v_2[/tex]
where;
m is the mass of the asteroidsu is the initial speed of the asteroidsv is the final speed of the asteroidsIf the initial speed both asteroids before collision is the same, then the asteroid with greater mass will have more momentum before collision while the asteroid with lesser mass will have greater momentum after collision to conserve the momentum.
The force of the impact depends of the velocity change and time of collision of the asteroids.
[tex]F = \frac{m\Delta v}{t}[/tex]
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A train travels 600 km in 4 hours. What is the speed of the train?
0.007 km/h
O 604 km/h
O 150 km/h
O 2,400 km/h
The speed of the train is 150 Km/h.
Speed can be defined as the distance travelled over a period of time. Mathematically, it can be expressed as:
Speed = Distance / Time
With the above formula, we can obtain the speed of the train as shown below:
Distance = 600 KmTime = 4 hours Speed =?Speed = Distance / Time
Speed = 600 / 4
Speed = 150 Km/h
Therefore, the speed of the train is 150 Km/h.
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which of the following statements describes how a balance obtains a measurement
A. A ruler is placed next to an object, and its length is noted.
B. An object is placed on one side and weights are placed on the other side until the two dishes are even.
C. The sides of an object are measured and multiplied to get the final measurement.
D. An object is placed in a cylinder, and the water displaced gives the measurement.
Which of the following statements describes how a balance obtains a measurement
Explanation:
A balance obtains a measurement by the sides of an object which are measured and multiplied to get the final measurement. Thus, the correct option is C.
How a balance obtains measurement?A balance is an instrument used for comparing the weights of two objects. It is usually for the scientific purposes, to determine the difference in mass or weight of an object.
Weighing of objects directly requires that the balance be carefully zeroed that is it reads zero with nothing on the balance pan in order to obtain accurate results of the measurement.
The sides of an object are measured and multiplied with a factor to get the final measurement of the object. Through this, a balance obtains the measurement.
Therefore, the correct option is C.
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Please help willing to give brainliest
Electromagnetic waves do not require a medium to travel. Which one
below is an example of an electromagnetic wave?
1.ultraviolet waves
2.sound waves
3.water waves
Answer:
sound water because sound is the most important electronic wave for water
Which statement describes the interaction between the north and south poles of two magents?
Answer:
A south pole attracts a north pole :)
Explanation:
I need help with number 7 please.
The SPEED of a car on the highway is 75 mph.
(You're correct on #6.)
9.
Un Pldle UI TUL!
What acceleration is produced on a mass of 200 g, when a force of 10 N is
exerted on it ?
Given parameters:
Mass of the body = 200g
Force on the body = 10N
Unknown parameters:
Acceleration produced by the force = ?
To solve this problem we must first define force in terms of mass and acceleration. This is possible due to the Newton's first law of motion.
Force = mass x acceleration
Here the unknown is acceleration and we can easily solve for it.
But we must take the mass to kilogram in order for it to cancel out.
1000g = 1 kg
200g = x kg = [tex]\frac{200}{1000}[/tex] = 0.2kg
Now input the parameters and solve;
10 = 0.2 x acceleration
Acceleration = [tex]\frac{10}{0.2}[/tex] = 50m/s²
The acceleration produced by the body is 50m/s²
Alcohol wiped across a tabletop rapidly disappears. What happened to the temperature of the tabletop
Answer:
it gets colder
Explanation:
because if you put anything on a table top it will become colder
A man climbs on to a wall that is 3.6 m high and gains 2222.64 J of potential
energy. What is his mass?
63 kg
17.5 kg
405 kg
617.4 kg
Which of the following elements are most likely to have similar chemical properties?
Answer:
transition metal, and inner transition metals groups are numbered 1-18 from left to right
f F= {mango, apple, banana, orange)
Answer:
n(F) = 4Explanation:
Cardinality of a set is the number of elements in that set. Given the set.
F= {mango, apple, banana, orange), we are to determine the cardinality of the set i.e the amount of fruit present in the set. Cardinality of the set F is represented as n(F).
Since there are 4 different fruit in the given set F, hence the cardinality of the set F is n(F) = 4
4. A tankful of liquid has a volume
of 0.2m3. What is the volume in (a)
lities (b) cm3 (c)ml
Explanation:
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the law conservation of____ states that matter can not be created or destroyed on changed from one to another
Answer:
energy
Explanation:
Energy can't be destroyed or created, just transferred.
Assume you push a 20 kg child in a little red wagon with a force of 100 N. However, the dirt and rocks below the wheels
create a frictional force of 25 N. What is the acceleration on the wagon and child?
A. 1.25 m/s2
B.3.75 m/s2
C. 5 m/s2
D. 0.2 m/s2
Answer:
a
Explanation:
Ray runs 78 feet north, then 61 feet west. Calculate the total displacement traveled by in feet
Answer:
hdhshsisjsbrtheisebvrtctvsjusyevevrvrg eggs haushehegehs
An object that gains electrons becomes ___charged?
Answer:The charge becomes nuetral
Explanation:
Whenever electrons are transferred between objects, neutral matter becomes charged. When an atom loses electrons, it becomes a positively charged ion, or cation. When an atom gains electrons, it becomes a negative charged ion, or anion.
• An evacuated long tube contains a coin and a feather. If both objects fall together starting from the top of the tube, it is expected that:
(a) the coin will reach the bottom first.
(b) the feather will reach the bottom first.
(c) both objects will reach the bottom at the same instant.
• If this experiment is repeated at a place 2000 kilometers above the sea-level, the acceleration due to gravity gexp is expected to :
(a) increase. (b) decrease. (c) remain constant.
Answer:
c-) both objects will reach the bottom at the same instant.
(b) decrease.
Explanation:
Although the feather is lighter than the coin, the tube where the experiment is performed is evacuated. Therefore there is no air that prevents the feather from falling freely with the same acceleration and speed as the coin.
In fact in the equations of kinematics proposed by Newton, the mass of the bodies is not taken into account, as we can see in the following equation:
[tex]v_{f}= v_{i} +g*t[/tex]
where:
Vf = final velocity [m/s]
Vi = initial velocity [m/s]
g = gravity acceleration [m/s^2]
t = time [s]
Therefore the answer is C.
Gravitational pull is a function of height, as the height of the body increases, the force of gravity decreases.
Please help in 5 mintues
A piece of chess game called master
a. king
b. queen
c. rook
d. bishop
how far will a body move in 4sec if uniformly accelerated from rest at the rate of 2m/s2
Answer:
32m
Explanation:
v=u+at
v=0+2×4
v=8m/s
d=vt
d=8×4
d=32m
I WILL MARK YOU AS BRAINLIEST IF RIGHT
You fall off the top of the Sears Tower and begin accelerating 9.8 m/s^2 toward the ground. If you fall for 10 seconds, how fast will you be going when you hit the ground ?
Answer:
Falling from the Sears Tower
• After 5 seconds, the ball falling from the
Sears Tower will have fallen
distance = ½ • 32 ft/s2 • (5 s)2 = 16 • 25
= 400 feet.
• We can turn the formula around to figure
out how long it would take the ball to fall all
the way to the ground (1450 ft)
Ætime = square root of (2 x distance/g)
Explanation:
a satellite is revolving around the sun in a circular orbit with uniform velocity v. if the gravitational force suddenly disappears the velocity of the satellite will be?
Answer:
when gravitational force suddenly disappears, then only centrifugal force will be acting and velocity is tangential to the orbit and hence, the satellite will fly off tangentially with same velocity v.
