Answer:
Explanation:
Gravity
Identify the heat transfer processes that determine the temperature of an asphalt pavement on a summer day. Write an energy balance for the surface of the pavement.
Answer:
Heat transfer processes: Radiation - Natural Convection
Energy balance:
[tex]\dot Q_{rad} -\dot Q_{conv} = \frac{dU_{sys}}{dt}[/tex]
[tex]\epsilon\cdot \sigma\cdot A_{s}\cdot (T_{s}^{4}-T_{a}^{4})-h\cdot A_{s} \cdot (T_{a}-T_{\infty}) = m\cdot c\cdot \frac{dT_{a}}{dt}[/tex]
Explanation:
The asphalt is heated due to the radiation from the sun and cooled by natural convection of the wind. By the First Law of Thermodynamics, we have the following model that represents the system:
[tex]\dot Q_{rad} -\dot Q_{conv} = \frac{dU_{sys}}{dt}[/tex] (1)
Where:
[tex]\dot Q_{rad}[/tex] - Heat transfer by radiation, measured in watts.
[tex]\dot Q_{conv}[/tex] - Heat transfer by natural convection, measured in watts.
[tex]\frac{dU_{sys}}{dt}[/tex] - Rate of change of thermal energy of the asphalt, measured in watts.
By applying the definitions for conduction, radiation and thermal energy, we expand (1) below:
[tex]\epsilon\cdot \sigma\cdot A_{s}\cdot (T_{s}^{4}-T_{a}^{4})-h\cdot A_{s} \cdot (T_{a}-T_{\infty}) = m\cdot c\cdot \frac{dT_{a}}{dt}[/tex] (2)
Where:
[tex]\epsilon[/tex] - Emissivity of the asphalt.
[tex]\sigma[/tex] - Stefan-Boltzmann constant, measured in watts per square meter-quartic Kelvin.
[tex]A_{s}[/tex] - Surface area of the asphalt, measured in square meter.
[tex]T_{s}[/tex] - Temperature of the sun, measured in Kelvin.
[tex]T_{a}[/tex] - Temperature of the asphalt, measured in Kelvin.
[tex]T_{\infty}[/tex] - Temperature of the wind, measured in Kelvin.
[tex]h[/tex] - Natural convection constant, measured in watts per square meter-Kelvin.
[tex]m[/tex] - Mass of the asphalt, measured in kilograms.
[tex]c[/tex] - Specific heat of the asphalt, measured in joules per kilogram-Kelvin.
Heat is conducted in the axial direction through a cylinder by heating one end. If the diameter of the cylinder is doubled (but the cylinder material, cylinder length, and the temperatures at both ends of the cylinder are unchanged), how will the heat transfer rate be changed
Answer:
hello your question is incomplete attached below is the complete question with the options
answer : Doubling the Diameter increases the heat transfer rate by a factor of 4 ( B )
Explanation:
The heat transfer in the axial direction of the cylinder can be calculated/determined as attached below
[tex]\frac{q_{2} }{q_{1} } = \frac{(2D)^2}{D^2}[/tex]
[tex]q_{2}[/tex] = 4[tex]q_{1}[/tex] ( This shows that Doubling the diameter increases the heat transfer rate by a factor of 4 )
Helppp
In Static Electricity, The charges do not ____
Answer:
basically I will tell you the definition
Explanation:
so when charges are unbalanced statistic energy is formed positive attract negative and negative attracts positive like repell while unlike attract .
Which of the following statements best represents a comparison of the two motions shown on the graph?
A. the top line represents a greater acceleration
B. the bottom line represents a greater acceleration
C. the top line represents a greater velocity
D. the bottom line represents a greater velocity
Answer:
C. the top line represents a greater velocity
Explanation:
The graph is a distance - time graph.
The distance is on the y-axis and time is on the x - axis.
For this graph, the slope is the velocity.
The steeper the line, the higher the velocity or the higher the slope. Since the upper line is steeper, it will have a higher slopeHence a greater velocityThe lower line is not so steep and its slope is lesser compared to the upper one.
The largest planet in the solar system is Jupiter,with a diameter of 71,398 km. What is the diameter of Jupiter in centimeters?
Answer:7139800000
Explanation:
The largest planet in the solar system is Jupiter. Its equatorial diameter is approximately 143,000 kilometres (ca. 88,856 mi miles).
What diameter of Jupiter in centimetres?Jupiter is a gas giant because it consists largely of gas and liquid, as opposed to solid substance. With an equator diameter of 142,984 kilometres (88,846 mi), it is the solar system's biggest planet.
About 80% of Jupiter is hydrogen, and 20% is helium. Over a solid core, a thick layer of liquid hydrogen is covered by swirling gas. At 1,000 kilometres below the cloud layer's outer edge, there is a lot of pressure. The hydrogen gas changes into a liquid there.
Therefore, By squaring the scale factor for length, the scale factor for area may be calculated. Consequently, s2 is the scale factor for area. If the situation is the opposite, a solution to the issue under investigation is offered. The area scale factor is 2.
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The kinetic energy of an object of mass 3.5 kg is 112 J. Its speed is?
64 m/s
8.0 m/s
5.67 m/s
6.8 m/s
What are homophones?
words that are spelled incorrectly several times in one paper
words that are spelled exactly as they sound
words that have different meanings depending on how they are used
words that have the same sound but different spellings and meaning
Answer:
words that have the same sound but different spellings and meaning
Explanation:
Homophones are generally words that sound the same but have different spellings and even meaning.
For example the words new and knew are homophones.
They have the same sound when pronouncing but their meaning is different.
Also, the words bawl and ball are homophones.
We see that both words have very similar pronunciation but their meanings are completely different.
Various radial points on a rotating Ferris wheel have: I. different linear velocities II. different angular velocities III. equal linear velocities IV. equal angular velocities
Answer:
I) True, II) False, III) False, IV) True
Explanation:
In this exercise, it is asked to answer different statements, for this we will use the relationship between angular and linear velocity
v = w r
let's review the claims
I) True. From the initial equation we see that the linear velocity depends on the radius
II) False. All points rotate with the same angular velocity
III) False. Linear velocity changes with radius
IV) True. The angular velocity of all points is the same
At various radial points on a rotating Ferris wheel have, different linear velocity (True), different angular velocity (false), equal linear velocity (false) and equal angular velocity (True).
The angular velocity of a rotating Ferris is calculated as follows;
[tex]\omega = \frac{v}{r} = 2\pi N[/tex]
The linear velocity of a rotating Ferris is calculated as follows;
v = ωr
where;
v is the linear velocityr is the radius of the Ferrisω is the angular velocityThe linear velocity increases with increase in radius.
Thus, we can conclude that, at various radial points on a rotating Ferris wheel have;
different linear velocitiesconstant angular velocityLearn more about angular velocity here: https://brainly.com/question/540174
At highway speeds, a particular automobile is capable of an acceleration of about 1.6 m/s. At
this rate, how long does it take to accelerate from 36 m/s to 50 m/s? (8.8 s)
Proof please
Answer:
8.8s
Explanation:
Given parameters:
Acceleration = 1.6m/s²
Initial velocity = 36m/s
Final velocity = 50m/s
Unknown:
Time taken for the acceleration = ?
Solution:
Acceleration is the rate of change of velocity with time;
Acceleration = [tex]\frac{Final velocity - initial velocity }{time taken }[/tex]
Insert the parameters and solve for time taken;
1.6 = [tex]\frac{50 - 36}{t}[/tex]
1.6t = 14
t = 8.8s
Myra is expected to be a great wife, an attentive mother, and an innovative designer. Sometimes she is overwhelmed by trying to juggle all of these pieces of her life. She can't spend as much time with her husband and kids whe
she is working a lot. Her work falters if she stays home to be with her family. What does Myra's scenario MOST accurately represent?
A. role conflict
B. agents of socialization
C. role strain
D. master status
Answer:
A
Explanation:
Myra is struggling to be a great wife, attentive mother, and an innovative designer all at the same time.
Myra's scenario is most accurately represented by role conflict because she is struggling to be a great wife, attentive mother, and an innovative designer all at the same time.
What is a role conflict?When there are expectations put on an individual that are not compatible with one another in relation to their profession or position, this may lead to role conflict. When a someone feels as if they are being tugged in several ways while attempting to react to the multiple statuses they hold, they are experiencing role conflict.
The work-family conflict, also known as the struggle one has when torn between the demands of personal and professional responsibilities, is perhaps the clearest illustration of role conflict.
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A student draws an energy diagram to explain why the temperature changes between a when a hot flask is placed inside of a cold beaker. What is wrong with the energy diagram below?
Answer:
there is not a picture below but it would be because the beaker was put in cold water then the temp decreased
Explanation:
Heredity is best described as th-
Explanation:
The most established layers are on the base, and the most youthful layers are on the top. Since dregs here and there incorporate once-living creatures, sedimentary stone regularly contains a great deal of fossils. Fossils are once living beings that have been transformed into rock, fit as a fiddle or type of the creature can in any case be seen.
A current of 310 is flowing through a copper wire with a resistance of 30 ohms. What is the voltage?
Answer:
930v
Explanation:
u=i*r
u=310*30=930v
When a 1.7 m tall man stands, his brain is 0.5 m above his heart.
If he bends so that his brain is 0.4 m below his heart, by how much does the blood pressure in his brain
changes? Note: PHeart=13.3x103
Pa.
Answer:
9.54 Kpa
Explanation:
Given :
Pheart = 13.3 * 10^3
Density of blood (ρ) = 1060 kg/m³
Difference in height of brain and heart in standing position = - 0.5
Difference in height of Brain a d heart in bending position = 0.4
g = acceleration due to gravity = 10 m/s²
Blood pressure of brain in standing position:
Pheart + ρ*g(-0.5)
13.3 * 10^3 + 1060 * 10 * - 0.5
13300 - 5300 = 8000 pascal = 8Kpa
Blood pressure of brain in bending position:
Pheart + ρ*g(0.4)
13.3 10^3 + 1060 * 10 * 0.4
13300 + 4240 = 17540 Pa = 17.54 Kpa
17.54Kpa - 8Kpa
= 9.54 Kpa
you discover that Eunice and Bert's go-kart weighs 400 kg and will have a 675 n force actung on it. how fast will it accelerate (to nearest tenth)
Answer:
200
Explanation:
subtract it it's 275
PLEASE ANSWER ASAP BEFORE MY TEACHER AND MY MOM KILLES ME PLEASE ASAP
The first person with the right answer gets to be a brainlest
In the attachment there is a density column where there is colour
Question: tell me why is the red at the bottom of the density column if it is the least dense
Explanation: That is not meant to be red, it‘s the bottom of the beaker. The star is at the very bottom of the beaker. it’s just the base of the beaker.
A 12.0-kg box is being pushed from the bottom to the top of a frictionless ramp. When the box is pushed at a constant velocity, the non-conservative pushing force does 58.0 J of work. How much work is done by the pushing force when the box starts from rest at the bottom and reaches the top of the same ramp with a speed of 1.50 m/s
Answer:
work done = 71.5 J
Explanation:
Given that,
Energy = Fifty eight J
Mass of box = 12.0 Kg
Speed = 1.5 m/s
U = work done
The external force acts solely on the box and also the earth system. conjointly note that the work done by external force
= modification of energy of the system
U = work done - K
Also recall that the box is moving with constant speed therefore, there will not be modification in acceleration, hence, there'll be no modification in K.E..
Therefore, K is adequate to zero.
K= 0
U = work done = energy
U = 58.0 J
work done by pushing force = K + U
work done = final K.E. - initial K.E. + U ........1
Initial K.E. = zero
Substitute the mandatory values into equation one
work done = 1/2m v² - zero + U
work done= 0.5 x 12.0 x 1.5² + 58.0
= 13.5+58.0
work done = 71.5 J
The world one by the pushing force is 71.5 J
What force controls the movement of the planets around the sun, holds together stars grouped in galaxies, and galaxies grouped in clusters? Thoroughly explain your answer, making sure to include an example and describe how this force keeps planets in orbit. Make sure to write at least 3-5 sentences and proper conventions (spelling, grammar, punctuation, etc.) to respond. Put all answers in your own words
Answer:
Gravity creates stars and planets by pulling together the material from which they are made.
Explanation: This is all I have I don't know if my test is the same a others though.
Answer:
Gravity
Explanation:
Gravity keeps things together. It is a force that attracts matter towards it. Anything with mass creates gravity
For a sound coming from a point source, the amplitude of the sound is inversely
proportional to the distance. If the displacement amplitude of an air molecule in a sound
wave is 3.2x10 m at a point 1 m from the source, what would be the displacement
amplitude of the same sound when the distance increases to 4 m?
(Question 3)
Answer ) Sound level equation
The intensity of a sound wave is related to its amplitude squared by the following relationship: I=(Δp)22ρvw I = ( Δ p ) 2 2 ρ v w . Here Δp is the pressure variation or pressure amplitude (half the difference between the maximum and minimum pressure in the sound wave) in units of pascals (Pa) or N/m2.
1.
In any solution, the part in the greatest quantity or volume is called the ___________.
solute
solvent
2.
The most common type of solution is a ___________-___________ solution.
liquid-solid
liquid-gas
3.
Air is a ___________-____________ solution.
solid-gas
Answer:
1) solvent
2) liquid-solid
3) gas - gas
Explanation:
1) A solution is the homogenous mixture of two or more substances in such a way that its components are uniformly distributed. In any solution, the solvent make up the greatest quantity or volume while the solute is of lesser quantity.
2) liquid-solid is the most common type of solution.
3) A gas solution can be a gas dissolved in a gas, or a liquid dissolved in a gas, or a solid dissolved in a gas. Air is a gas - gas solution, it is composed of oxygen and other dissolved gases in nitrogen
Answer:
B, A, B
Explanation:
had this USA test prep
Which of the moon's properties prevents it from being pulled inward by Earth?
O gravity
O inertia
O shape
O structure
Answer:
O inertia
Explanation:
The moon's property that prevents it from being pulled inward by the Earth is called it's inertia.
Every object in the universal space have gravitational force of attraction to one another due to their masses.
An inertia is the reluctant of a body to move or the tendency of it to remain in constant motion.
Inertia entails the property of objects to remain at rest or continue in uniform motion.
As the force of gravity acts between the earth and the moon, inertia keeps a body in constant position.
Copenhagen is located 780 km North and 810 km East of Paris. A flight from Paris to Copenhagen takes two hours. Typically the wind blows from East to West over Europe, but the speed varies. For one particular flight, the wind speed was 165 km/h. What is the magnitude of vpa, the plane's velocity with respect to the air
Answer:
[tex]V_{pa}=690km/hr[/tex]
Explanation:
In order to solve this problem, we can start by drawing a diagram of what the problem looks like. (See attached picture).
We can treat this as a vector problem, so we can start by finding the velocities of the plane with respect to the earth as it goes north and east. Velocity is found by using the following formula:
[tex]Velocity=\frac{distance}{time}[/tex]
so
[tex]V_{paN}= \frac{780km}{2hr}[/tex]
[tex]V_{paN}=390 km/hr[/tex]
Since air isn't affecting the north direction of the plane, we will keep this as the velocity due north.
Now let's find the velocity of the plane with respect to the earth towards the east:
[tex]V_{pE}=\frac{810km}{2hr}[/tex]
[tex]V_{pE}=405 km/hr [/tex]
In this case, since the wind is blowing from east to west, then it affects directly the velocity of the plane with respect to the earth, so we can use the following formula to determine the Velocity of the plane with respect to the air in the eastern direction:
[tex]V_{paE}-V_{a}=V_{pE}[/tex]
so we can solve this for the velocity of the plane on the air towards the east, so we get:
[tex]V_{paE}=V_{pE}+V_{a}[/tex]
so we get:
[tex]V_{paE}=405 km/hr + 165km/hr[/tex]
[tex]V_{paE}=570 km/hr[/tex]
So now we can use this data to find the velocity of the plane with respect to the air:
[tex]V_{pa}=\sqrt{V_{paN}^{2}+V_{paE}^{2}}[/tex]
so we get:
[tex]V_{pa}=\sqrt{(390km/hr)^{2}+(570km/hr)^{2}}[/tex]
[tex]V_{pa}=690.65 km/hr[/tex]
A 1.5 x 10 3kilogram car is moving at 10 meters per second east. A braking force acts on the car for 5.0 seconds, reducing its velocity to 2.0 meters per second east. ??
Answer:
What should we find state that first.
Define specific charge of an electron. Write its value.
Answer:
The specific charge is defined as a charge by mass ratio i.e e/m. The charge on an electron (e) = 1.602 X 10-19C. The mass of the electron (m) = 9.1×10−31Kg.
A football game starts with a kickoff. If the ball is kicked with a velocity of 72 m/s 35 o to
the horizontal. How far will the football travel? What is the speed an angle of impact?
Explain please
Answer:
Explanation: very far
State one activity in our daily life by using the characteristic of iron rod.
Answer:
In our house ceilings.
Explanation:
In our daily life, iron rod is used in the construction of ceiling of our homes which made our ceiling stronger enough to make it multi story. It is extensively used in big construction projects such as multi story buildings and other tall buildings etc. So we can say that iron rod is used for construction of big houses and buildings.
A 600 kg elevator starts from rest. It moves upward for 4.50 s with constant acceleration until it reaches its cruising speed, 1.75 m/s. (a) What is the average power of the elevator motor during this period
Answer:
408.33watts
Explanation:
Power is expressed according to the formula
Power = work done/time
Power = force × distance/time
Power = Force× velocity
Find the force
F = mv/t
F = 600×1.75/4.5
F = 1050/4.5
F=233.33N
Get the power
Power = 233.33×1.75
Power = 408.33watts
Hence the average power of the elevator motor during this period is 408.33m/s
Define friction. Prove that tangent of angle of friction is equal to coefficient
of friction.
Answer:
Explained below
Explanation:
- Friction is the force that opposes the motion between two or more objects/surfaces in contact with each other.
- On an inclined plane, the coefficient of static friction is given by the relation;
μ = F_max/F_n
Where;
F_max is maximum frictional force before slip = mg sin θ
F_n is normal force = mg cos θ
Thus;
μ = mg sin θ/mg cos θ
μ = tan θ
A 0.500-kg object connected to a light spring with a spring constant of 20.0 N/m oscillates on a frictionless horizontal surface. (a) Calculate the total energy of the system and b) the maximum speed of the object if the amplitude of the motion is 3.00 cm. (c) Compute the kinetic and potential energies of the system when the displacement is 2.00 cm
Answer:
a = 0.009 J
b = 0.19 m/s
c = 0.005 J and 0.004 J
Explanation:
Given that
Mass of the object, m = 0.5 kg
Spring constant of the spring, k = 20 N/m
Amplitude of the motion, A = 3 cm = 0.03 m
Displacement of the system, x = 2 cm = 0.02 m
a
Total energy of the system, E =
E = 1/2 * k * A²
E = 1/2 * 20 * 0.03²
E = 10 * 0.0009
E = 0.009 J
b
E = 1/2 * k * A² = 1/2 * m * v(max)²
1/2 * m * v(max)² = 0.009
1/2 * 0.5 * v(max)² = 0.009
v(max)² = 0.009 * 2/0.5
v(max)² = 0.018 / 0.5
v(max)² = 0.036
v(max) = √0.036
v(max) = 0.19 m/s
c
V = ±√[(k/m) * (A² - x²)]
V = ±√[(20/0.5) * (0.03² - 0.02²)]
V = ±√(40 * 0.0005)
V = ±√0.02
V = ±0.141 m/s
Kinetic Energy, K = 1/2 * m * v²
K = 1/2 * 0.5 * 0.141²
K = 1/4 * 0.02
K = 0.005 J
Potential Energy, P = 1/2 * k * x²
P = 1/2 * 20 * 0.02²
P = 10 * 0.0004
P = 0.004 J
The total energy of the system is 0.009 J
The maximum speed of the object is 0.19 m/s
The kinetic and potential energies of the system when the displacement is 2.00 cm are 0.005 J and 0.004 J respectively
The object is under simple harmonic motion.
Given that the mass of the object m =0.5 kg , spring constant k = 20N/m
(a) The total energy of the system in SMH,
[tex]E=\frac{1}{2}kA^2[/tex]
If the amplitude of motion A = 3cm = 0.03m, then total energy
[tex]E=\frac{1}{2}*20*0.03*0.03 J\\\\E = 0.009J[/tex]
E = 0.009J is the total energy of the system.
(b) maximum speed of the object
the maximum kinetic energy of the object = total energy of the object
[tex]\frac{1}{2} m(v_{max})^{2} =E\\\\v_{max}=\sqrt{2E/m}\\\\v_{max}=\sqrt{2*0.009/0.5}\\\\v_{max}=0.19m/s[/tex]
0.19 m/s is the maximum speed
(c) KE and PE when x = 2cm = 0.02m
potential energy at x = 0.02
[tex]PE=\frac{1}{2}kx^2\\\\PE=\frac{1}{2}*20*0.02*0.02\\\\PE= 0.004J[/tex]
Now, Kinetic energy + potential energy = total energy
KE + PE = E
KE = E - PE
KE = 0.009J - ).004J
KE = 0.005J
The kinetic and potential energies are 0.005 J and 0.004 J respectively.
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What is the available energy content, in joules, of a battery that operates a 2.00-W electric clock for 18 months
Answer:
93312000 Joules
Explanation:
Energy can be explained as the capacity for doing work. And can be expressed as
E= pt....................eqn(1)
Where
E= Energy in Joules
P= power in Watt= 2.00W
t= time in seconds
Time= 18 months, which can be converted to "seconds" as;
18 months = [ 18 monthsx 30 days x 24 hours x 60 min x 60 sec] = 46656000
Then
time= 46656000 seconds
Power=2 watt
If we substitute into equation (1) we have
Energy = 2 watt × 46656000 seconds
Energy= 93312000 Joules
