Answer:
A
Explanation:
Detailed balance, i.e. 2nd law of thermodynamics, requires a relationship between absorbing incoming radiation and turning it into heat, versus emitting thermal radiation. A perfect mirror at rest does not absorb any incoming radiation, therefore it is a "whitebody", not a blackbody, and emits no thermal radiation.
Answer:
A. it reflects most electromagnetic radiation instead of absorbing it.
Explanation:
a p e x, just took the quiz
Three children are struggling and pulling on a single toy. Two of the children, Abe and Barry, are EACH (individually) pulling with a force of 60 Newtons. The third child, Eric, is pulling with enough force to exactly balance Abe and Barry (no child is winning the tug-o-war for the toy). We can label our forces A, B, and E (from each child's name). These three forces are in equilibrium.
If Abe is pulling toward the North and Barry is pulling toward the East, we want to find the total force R due to Abe and Barry (the Resultant of their forces). Note: in THIS case the two forces and R form a right-triangle (with R as the hypotenuse) - as seen using graphical vector addition. As a convention let's have NORTH upward and EAST rightward on this page.
a. Sketch an ACCURATE free-body diagram (three arrows outward from a point showing LABELED forces A, B, and E - each arrow a reasonable length and correct direction):
b. Sketch a labeled diagram for graphical addition of A and B to get R:
c. Show the calculation of the magnitude of R from the magnitudes of A and B:
d. Give the magnitude of force E (in units of Newtons):
e. Describe the direction of force E in terms of the "cardinal" directions (north, east, south, and/or west):
Solution :
c). [tex]$\vec{F}_A = $[/tex] force applied by Abe
[tex]$\vec{F}_B = $[/tex] force applied by Barry
[tex]$\vec{F}_E = $[/tex] force applied by Eric
[tex]$\vec{F}_R = $[/tex] Resultant force
[tex]$\vec{F}_A $[/tex] in the vector form can be written as :
[tex]$\vec{F}_A = 0 \hat{i} + 60 \hat{j}$[/tex]
[tex]$\vec{F}_B $[/tex] in the vector form can be written as :
[tex]$\vec{F}_B = 60 \hat{i} + 0 \hat{j}$[/tex]
The resultant,
[tex]$\vec{F}_R= \vec{F}_A+\vec{F}_B $[/tex]
[tex]$=(0 \hat i + 60 \hat j)+(60 \hat i + 0\hat j)$[/tex]
[tex]$=60 \hat i + 60 \hat j$[/tex]
[tex]$|\vec{F}_R| = \sqrt{60^2+60^2}$[/tex]
= 84.853 N
d). As the three forces are in equilibrium, therefore,
[tex]$|\vec F_E| = |\vec F_R|$[/tex]
[tex]$|\vec F_E| =84.853 \ N$[/tex]
e). The direction of the force exerted by Eric is exactly opposite to the direction of the resultant force.
The direction of the resultant force is :
[tex]$\theta = \tan ^{-1}\left(\frac{F_y}{F_x}\right)$[/tex]
[tex]$ = \tan ^{-1}\left(\frac{60}{60}\right)$[/tex]
= 45° north east
The direction of the force E is 45° west or 45° south west.
PLEASE HELP!!!!
ITS URGENT!
Answer:
the answer is D
Explanation:
The figure below shows the head of a patient being fixed to a
Russell Traction System, where the patient is laying down on his
back on a bed that is inclined by 20° with the horizontal as
shown. The static frictional force between the patient and the
bed is 190N and the coefficient of static friction is 0.4.
(a) Find the weight of the patient.
(b) Find the minimum balancing mass, M that stretches the
patient from
Answer:
a) 505.5
Explanation:
draw all the forces acting on the body then
w cosθ = Fn --> W = [tex]\frac{Fn}{cos\\}[/tex]
we can find Fn from
Fs= MEU(s) x Fn
What problem did Katherine face in checking other people’s calculations in the movie ¨Hidden figures¨
Answer:
Information from the leading mathematicians was considered "classified".
[O.04H]The table below shows the use of some energy production methods over time.
Type of energy Average energy used annually in the past (in million tons) Average energy used annually at present (in million tons) Average energy most likely to be used annually in the future (in million tons)
Oil 200 4000 300
Gas 100 2500 700
Coal 1000 2500 1500
Wind 0.1 50 2000
Hydropower 0.7 60 150
Tidal power 0.02 50 500
Based on the table, which of these statements best describes the impact of different methods of energy production on the environment in the past?
There was a rise in the height of tides.
There was a rise in greenhouse gases.
The coastal ecosystem was harmed.
The coastal areas were highly polluted.
I think The coastal areas were highly polluted
Answer:
i think its greenhouse gases may increase
Explanation:
Martin has hypothesized that the size and types of trees differ between valleys and higher elevations. He sets up a transect line in a wooded valley and randomly creates three 10 x 10 meter plots along the transect line, recording GPS coordinates for the northwest corner of each plot. He identifies and measures (diameter at breast height) every tree within the plots. He repeats this procedure in a wooded area on the ridge above the valley.
Using the scenario above, state the independent and dependent variables.
Answer: The dependent Variables include: Size and Types of trees.
The independent Variables include:
geographic elevations that is, valleys and the higher elevations.
Explanation:
The dependent variable simply refers to the variable a researcher tests or measures during an experiment. On the other hand, the independent variable simply refers to the variable that's controlled during an experiment.
Based on the definition above, the dependent variables include the size and the types of trees while the independent variables include the
geographic elevations that is, the valleys and the higher elevations.
Oberon is a moon of Uranus. It has a mass of 3.01 x 1021 kg and is 761.4 km away from Uranus. If the force of gravity
of Uranus is pulling 3.00 x 1025 N on Oberon, what is the mass of Uranus? (6 points)
Answer:
acc to formula= F= G m1m2/rsq
mass of Uranus= F×r sq/G×m
M=3.00×10^25×761.4×761.4×10^6/6.67×10^ -11×3.01×10^21
=3×10^25-8×7614×7614/667×301×10^-2-11+21-2
=173918988×10^11/200767
=866×10^11(approx)
Studying children's interactions by watching them play on the school playground is
an example of
a survey.
naturalistic observation.
a case study.
a single-blind study.
Answer:
a survey
Explanation:
how kids like the playground or they do not like it at all
Which are uses of convex mirrors? Check all that apply.
magnifying mirrors for putting on makeup
side-view mirrors on vehicles
hallway safety mirrors
focusing automobile headlights
lenses in sunglasses
Answer:
B. Side-view mirrors on vehicles
C. Hallway safety mirrors
E. Lenses in sunglasses
Explanation:
Trust Me, Look At Attachment.
Answer:
2, 3, and 5 on Edge, 2022.
Explanation:
I had this question on Edge.
(See the attachment below.)
The rest of the answers are:
O Slide 8 - Sample Response: The image seems to be behind the mirror, but nothing is really there.
O Slide 9 - Concave
O Slide 10 - Same size
On July 4, 2005, the NASA spacecraft Deep Impact fired a projectile onto the surface of Comet Tempel 1. This comet is about 9.0 km across. Observations of surface debris released by the impact showed that dust with a speed as low as 1.0 m/s was able to escape the comet.
1. Assuming a spherical shape, what is the mass of this comet? ( The escape speed for an object at the surface of Earth is 11.2 km/s).
Express your answer using two significant figures.
M = ____________ kg
2. How far from the comet's center will this debris be when it has lost 60% of its initial kinetic energy at the surface?
Express your answer using two significant figures.
r = ____________ km
Answer:
1. M = 67,422,800,892,977.54 kg
2. r = 15 km
Explanation:
The diameter of the Comet Tempel 1, D = 9.0 km across
The speed with which the dust escapes = 1.0 m/s
1. The escape velocity, [tex]v_e[/tex], is given by the following formula
[tex]v_e = \sqrt{\dfrac{2 \cdot G \cdot M}{R} }[/tex]
Where;
G = The universal gravitational constant = 6.67430 × 10⁻¹¹ N·m²/kg²
[tex]v_e[/tex] = The escape velocity of the debris = 1.0 m/s
M = The mass of the comet from where the debris escapes
From the escape velocity equation, we have;
[tex]M = \dfrac{v_e^2 \cdot R}{2 \cdot G}[/tex]
Plugging in the values for the variables, we get the mass of the comet, 'M', as follows;
[tex]M = \dfrac{1.0^2 \times 9,000}{2 \cdot 6.67430 \times 10^{-11}} \approx 67,422,800,892,977.54 \, kg[/tex]
The mass of the comet, M ≈ 67,422,800,892,977.54 kg
2. When the debris has lost 60% of its initial kinetic energy, we have;
[tex]60\% \, K.E. = 0.6\cdot K.E. = 0.6 \times \dfrac{1}{2} \times m \times v_e^2 = \dfrac{G \cdot M \cdot m}{r}[/tex]
[tex]\therefore \, The \ distance \ of \ debris \ from \ the \ center, \, r = \dfrac{G \cdot M }{0.6 \times \dfrac{1}{2} \times v_e^2 }[/tex]
[tex]r = \dfrac{6.67430 \times 10^{-11} \times 67,422,800,892,977.54}{0.6 \times \dfrac{1}{2} \times 1^2 } = 15,000[/tex]
When the debris has lost 60% of its initial kinetic energy, the distance the debris will be from the comet's center, r = 15,000 m = 15 km
write any three utilities of plastics
Explanation:
container, bottles, boxes, cups
If the mass of an object increases by a factor 2, kinetic energy?
Options:
A) Increases by a factor of 2
B) Increases by a factor of 4
C) Decreases by a factor of 2
D) Decreases by a factor of 4
Answer:
A) Increases by a factor of 2
Explanation:
Kinetic energy can be defined as an energy possessed by an object or body due to its motion.
Mathematically, kinetic energy is given by the formula;
[tex] K.E = \frac{1}{2}MV^{2}[/tex]
Where;
K.E represents kinetic energy measured in Joules.
M represents mass measured in kilograms.
V represents velocity measured in metres per seconds square.
Given that mass, m = 2m
Substituting into the equation, we have;
K.E = ½mv²
K.E = ½*2mv²
Cross-multiplying, we have;
2K.E = 2mv²
Hence, if the mass of an object increases by a factor 2, kinetic energy is increased by a factor of 2.
A laser beam with a frequency of 180 Hz forms an 8 m standing wave with 10 nodes.
How many nodes would be formed by the same beam over the same distance at 600 Hz?
What are the nodes?
Answer:33
Explanation:
F = frequency
N = Node count
w = wave lenght
v = wave velocity
L = distance wave traveled
First find wave length of laser
w = (2/(N))*(L)
w = (2/(10))*(8)
w = 1.6
then using (w), find velocity
V = (w)(F)
V = (1.6)*(108)
V = 288
Plug in V and the new frequency to solve for new node count
F = NV/2L
(600) = (N)*(288) / 2 * (8)
(N) = 33.33
there are 33 nodes
A Body OF Volume 36cc Floats With 3/4 of its volume submerged in water . The density Of Body is
1. 0.25g/cc 2. 0.75g/cc
3. 0.9g/cc 4. 0.1g/cc
Answer:
Density of body = 0.25g/cc
Explanation:
Given:
Volume submerged in water = 3/4
Find:
Density Of Body
Computation:
Density of body = fraction of body in liquid x density of water
Density of body = [1-3/4]1
Density of body = 0.25g/cc
In a 1953 experiment a rocket sled went from 284 m/s to rest within 178 m. If the test subject, John Stapp, had a mass of 84.0 kg: a) what is the amount of Work done to stop the John Stapp? b) how much Force was applied to John Stapp?
The velocity of an object with mass = 2kg is given as a function of time:
V = 2ti + 4[tex]t^{2}[/tex]j
Find the force acting on the object at t = 2 seconds.
Answer:
The force acting on the object at [tex]t = 2\,s[/tex] is [tex]\vec F = (4, 32)\,[N][/tex].
Explanation:
Given that object has a constant mass in time, the force acting on the object ([tex]\vec F[/tex]), in newtons, is defined by following expression:
[tex]\vec F = m\cdot \vec a[/tex] (1)
Where:
[tex]m[/tex] - Mass, in kilograms.
[tex]\vec a[/tex] - Acceleration, in meters per square second.
By definition of acceleration, we know that:
[tex]\vec a = \frac{d}{dt} \vec v[/tex] (2)
Let suppose that given vector velocity is expressed in meters per second. If we know that [tex]m = 2\,kg[/tex], [tex]\vec v = (2\cdot t, 4\cdot t^{2})\,\left[\frac{m}{s} \right][/tex] and [tex]t = 2\,s[/tex], then the force acting on the object is:
[tex]\vec a = (2, 8\cdot t)\,\left[\frac{m}{s^{2}} \right][/tex]
[tex]\vec F = (4, 16\cdot t)\,[N][/tex]
[tex]\vec F = (4, 32)\,[N][/tex]
The force acting on the object at [tex]t = 2\,s[/tex] is [tex]\vec F = (4, 32)\,[N][/tex].
Which of the following planets were the ancient Greeks able to see and make careful observations of?
Saturn and Neptune
Neptune and Uranus
Mars and Venus
Mercury and Uranus
Answer:
Neptune and Uranus
Explanation:
Did a quiz on this not to long ago
Look at the graph. What is the slope of the line?
For the first hour, the slope is zero.
After that, the slope is -2 miles per hour.
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DOCS
3. A ball is thrown vertically upward from a window that is 3.6 m above the ground. The ball's initial speed is
2.8 m/s and the acceleration due to gravity is 9.8 m/s2
[ 6 marks]
(a) What is the ball's speed when it hits the ground?
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(b) How long after the first ball is thrown should a second ball be simply dropped from the same window so
that both balls hit the ground at the same time?
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Answer:
?
Explanation:
If 11,550 J heat is absorbed by a copper object when it is heated from 20.0°C to 30.0°C,
what is the mass of the copper?
The specific heat of copper is 385 J/kgK.
Answer:
The mass of the copper is 3.00kg
Explanation:
Light passing through a double slit
with separation d = 2.42x10-5 m
creates its second maximum (m = 2)
at an angle of 2.74 deg. What is the
wavelength of the light, IN
NANOMETERS?
(Hint: The answer will be between 400 and
700.) (Unit = nm)
Answer:
573
Explanation:
totally not stealing previous answer cause I know it's right
The wavelength of the light is 578.45 nm.
Light passing through a double slit with separation is given as
d = 2.42 × 10⁻⁵ m.
Line number m = 2
Angle θ = 2.74°
How wavelength is calculated and what is the wavelength of the light?The distance between two sound waves i.e., crest and trough is called the wavelength.
To find the wavelength, here we use the formula as,
sin θ = Line number × λ ÷ ( distance )
By substituting all the given values,
Sin ( 2.74° ) = 2 × λ ÷ ( 2.42 × 10⁻⁵ )
Rearranging the equation,
λ= (Sin ( 2.74° ) × ( 2.42 × 10⁻⁵ ) ) ÷ (2)
λ = 578.45 nm.
Thus, wavelength λ of the light is 578.45 nm.
Learn more about wavelength,
https://brainly.com/question/12924624
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Calculate the acceleration of a school bus that was stopped at a bus stop and then traveled down the road at a speed of 15 meters per second in 13 seconds
A student lifts their 75 N backpack 0.50 m onto their chair. How much work is done?
Answer:
37.5 J
Explanation:
With work done equation: W=Fs
W=75*0.50=37.5 J
or use mgh=(75)(0.5) which is the same
A football (450 g) falls vertically from rest onto the ground from a height of 5.0 m. If the force that
compresses the ball when it hits the ground is (100 N). What is the amount of compression of the ball?
Draw explanatory diagram.
marks]
a mass of 0.8kg at the end of a rope 0.5m long is whirled round ina horizontal circle at an angular speed of 10 rads^-1. what is it's angular momentum?
Answer:
L = 2 J.s
Explanation:
The angular momentum of an object travelling in a horizontal circle is given by the following formula:
[tex]L = mvr[/tex]
where,
L = Angular momentum = ?
m = mass = 0.8 kg
v = linear speed = rω
r = radius of circular path = length of rope = 0.5 m
ω = Angular Speed = 10 rad/s
therefore,
[tex]L = mr^2\omega\\L = (0.8\ kg)(0.5\ m)^2(10\ rad/s)\\[/tex]
L = 2 J.s
A person drives a car around a circular road with a constant speed of 20 m/s. The
radius of the circular road is twenty-five meters. What is the acceleration of the car?
o 20 m/s2
O 16 m/s2
O 10 m/s2
O 8 m/s2
Answer:
16 m/s^2
Explanation:
acceleration tangential = (v^2)/r
a=400/25
a=16 m/s^2
Side note: next time, be more specific when asking about acceleration in circular motion. There's more than one type! Example:
angular acceleration=acceleration tangential/r
angular acc.=16/25
angular acc.=0.64 rad/s^2
Suppose it takes at least 5 people to push a very heavy box up a 400-cm ramp. If there are actually 6 people there to help push, which ramp(s) could they use to get the box moved? (Assume no friction.)
Suppose it takes at least 5 people to push a very heavy box up a 400-cm ramp. If there are actually 6 people there to help push, they could use ramp(s) = 480 cm to get the box moved.
What is force?According to newton if there is a object at rest then a physical or non physical thing acting on it and it helps him to move a bit that called the force. It is a vector quantity. It can be measured in newton, dyne.
How can we calculate the ramp?To calculate the ramp we are using the formula,
s= s₁×(p₂/p₁)
Here we are given,
s₁= The initial length of the ramp. = 400m
p₂= The final number of people. = 6
p₁=The initial number of people. = 5
We have to calculate the final length of ramp.= s cm
Now we put the values in above equation, we get
s= s₁×(p₂/p₁)
Or, s= 400×(6/5)
Or, s=480 cm
From the above calculation we can say that, If there are actually 6 people there to help push, they could use ramp(s) = 480 cm to get the box moved.
Learn more about force:
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Your television picture is created by 480 horizontal lines of pixels, arranged on a screen of total height h. Assume that your ability to resolve the lines is limited only by the Rayleigh criterion, and that the pupils of your eyes are 5.12 mm in diameter. Beyond a certain distance from the screen D, you won't be able to resolve individual lines of pixels and the TV picture will not appear pointillistic. Calculate this ratio D/h of minimum viewing distance to screen height. Assume that the average wavelength of the light coming from the screen is 537 nm.
Answer:
Ratio D/h of minimum viewing distance to screen height is 16.28
Explanation:
Given the data in the question;
Rayleigh criterion sin[tex]\theta[/tex] = 1.22 λ/D
D is diameter (5.12 mm) = 5.12 × 10⁻³
λ is wavelength ( 537 nm) = 537 × 10⁻⁹ m
so we substitute
sin[tex]\theta[/tex] = 1.22 × 537 × 10⁻⁹ / 5.12 × 10⁻³
sin[tex]\theta[/tex] = 655.14 × 10⁻⁹ / 5.12 × 10⁻³
sin[tex]\theta[/tex] = 0.000127957
[tex]\theta[/tex] = sin⁻¹ ( 0.000127957 )
[tex]\theta[/tex] = 0.007331°
now, tan[tex]\theta[/tex] = y/D
y = h/480
so
tan[tex]\theta[/tex] = h/480 / D
h/D = 480 × tan[tex]\theta[/tex]
D/h = 1 / ( 480 × tan[tex]\theta[/tex] )
we substitute in value of [tex]\theta[/tex]
D/h = 1 / ( 480 × tan( 0.007331° ) )
D/h = 1 / ( 480 × 0.00012795 )
D/h = 1 / 0.061416
D/h = 16.28
Therefore, Ratio D/h of minimum viewing distance to screen height is 16.28
explain the role of good marketing in the success of business
Answer:
I am joker if you are mad x_________-..............,,,,,,........ €£
A 2-C charge experiences a force of 40 N when put at a certain location in
space. The electric field at that location is a. 2 N/C.b. 20 N/C. c. 30 N/C. d.
40 N/C. e. 60 N/C.
Answer:
E = 20 N/C
Explanation:
Given that,
Charge, q = 2 C
Force experience, F = 40 N
We need to find the electric field at that location.
The electric field in terms of electric force is given by :
F = qE
Where
E is the electric field
[tex]E=\dfrac{F}{q}\\\\E=\dfrac{40\ N}{2\ C}\\E=20\ N/C[/tex]
So, the electric field at that location is 20 N/C.