Answer:
They can be penetrated only with longer wavelengths such as radio and infrared.
Explanation:
A dark nebula can be defined as an interstellar cloud that is so dense as a result of high concentration of gas and dust and as such it obscures the visible wavelengths of light from stars behind it, thus appearing completely opaque (dark patch) in front of a bright emission nebula or in regions having plenty stars.
Hence, dark nebulae can be penetrated only with longer wavelengths such as radio and infrared light because they cannot be absorbed by the dust layers or particles coated with frozen carbon monoxide and nitrogen residing in the dark nebulae.
A rock is thrown at a window that is located 16.0 m above the ground. The rock is thrown from the ground at an angle of 40.0° above horizontal with an initial speed of 30.0 m/s and experiences no appreciable air resistance. If the rock strikes the window on its upward trajectory, from what horizontal distance from the window was it released?
Answer:
x = 27.3 m
Explanation:
This is a projectile launching exercise, let's start by looking for the time it takes for the rock to reach the height of the window.
Let's use trigonometry to find the velocities of the rock
sin 40 = [tex]v_{oy}[/tex] / v
cos 40 = v₀ₓ / v
v_{oy}= v sin 40
v₀ₓ = v cos 40
v_{oy} = 30 sin 40 = 19.28 m / s
v₀ₓ = v cos 40
v₀ₓ = 30 cos 40 = 22.98 m / s
we look for the time
[tex]v_{y}^2[/tex] = v_{oy}^2 - 2 g y
v_{y}^2 = 19.28 2 - 2 9.8 16 = 371.71 - 313.6 = 58.118
v_{y} = 7.623 m / s
we calculate the time
v_{y} = v_{oy} - gt
t = (v_{oy} - v_{y}) / g
t = (19.28 -7.623) / 9.8
t = 1,189 s
since the time is the same for both movements let's use this time to find the horizontal distance
x = v₀ₓ t
x = 22.98 1,189
x = 27.3 m
What benefits does preforming this investigation in the physical world have over the computer simulation?
Please help!!
Explanation:
Can be safer and cheaper than the real world. Able to test a product or system works before building it. Can use it to find unexpected problems. Can speed things up or slow them down to see changes over long or short periods of time.
.
.
.
.
Answer:
"Performing this experiment in the physical world gives you more control over which parameters you can adjust. You also gain experience with scientific equipment and procedures. In addition, there may be flaws in the computer model, since no model is perfect."
Explanation:
edmentum
Find out the name of metals which can be obtained from the following .a) argentite b)hematite c)chalcopryite d)bauxite e)calverite
Answer:
a). Silver, Ag
b). Iron, Fe
c). Copper, Cu
d). Aluminium, Al
e). Gold, Au
Hess's law states that:
A. Energy cannot be created nor destroyed, it can only change form.
B. The enthalpy change when 1 mole of a substance undergoes complete combustion under standard conditions is equal to molar masses of the compounds.
C. When the enthalpy changes under standard conditions, 1 mole of a substance is formed from its elements.
D. The overall enthalpy change for a reaction is independent of the route the reaction takes.
Answer:
D. The overall enthalpy change for a reaction is independent of the route the reaction takes.
Answer: Hess's law states that the overall enthalpy change for a reaction is independent of the route the reaction takes. Option D is correct.
It is given Hess's law.
It is required to state the Hess's law.
What is Hess's law ?Thermochemical equations can be manipulated to give the data chemical reactions. We find exactly how much energy will be absorbed or released by the reaction because we may face various explosions.
There are mainly two ways to calculate ΔH of any reaction. First If the reaction has ΔH then the reverse of the reaction will have opposite ΔH and the second is if double the ΔH of the substances, double the ΔH.
Therefore Hess's law states that the overall enthalpy change for a reaction is independent of the route the reaction takes.
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A long, straight, horizontal wire carries a left-to-right current of 40 A. If the wire is placed in a uniform magnetic field of magnitude 3.7 ✕ 10−5 T that is directed vertically downward, what is the resultant magnitude of the magnetic field 22 cm above the wire (in T)?
Answer:
The magnitude of the resultant of the magnetic field is [tex]4.11\times10^{-5}\ T[/tex]
Explanation:
Given that,
Current = 40 A
Magnetic field [tex]B=3.7\times10^{-5}\ T[/tex]
Distance = 22 cm
We need to calculate the magnetic field
Using formula of magnetic field
[tex]B'=\dfrac{\mu_{0}I}{2\pi r}[/tex]
Where, r = distance
I = current
Put the value into the formula
[tex]B'=\dfrac{4\pi\times10^{-7}\times20}{2\pi\times0.22}[/tex]
[tex]B'=1.8\times10^{-5}\ T[/tex]
We need to calculate the magnitude of the resultant of the magnetic field
Using formula of resultant
[tex]B''=\sqrt{B^2+B'^2}[/tex]
Put the value into the formula
[tex]B''=\sqrt{(3.7\times10^{-5})^2+(1.8\times10^{-5})^2}[/tex]
[tex]B''=4.11\times10^{-5}\ T[/tex]
Hence, The magnitude of the resultant of the magnetic field is [tex]4.11\times10^{-5}\ T[/tex]
plz help
I need it fast
Answer:
perpendicular to
Explanation:
it means perpendicular to .....should u come across something like this / / , this one means parallel to .....
Answer:
perpendicular
Explanation:
Some of the most popular symbols are:
Heart symbol: this represents love, compassion and health.
Dove symbol: this represents peace, love, and calm.
Raven symbol: this represents death and doom.
Tree symbol: this represents growth, nature, stability, and eternal life.
Owl symbol: this represents wisdom and intelligence.
what do you mean by 5meter length
Answer:
h, nzk SC j AZ hsbzkzjx NM s in xbxnjxjxwhat is the story of coal
Explanation:
Coal is a fossil fuel and is the altered remains of prehistoric vegetation. The energy we get from coal today comes from the energy that plants absorbed from the sun millions of years ago. In the burning process of coal, carbon dioxide (CO2) is emitted. Humans expel CO2, and plants utilize it every single day. Carbon is a building block for all forms of life and is used in a lot of everyday products.
Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen.Coal is formed when dead plant matter decays into peat and is converted into coal by the heat and pressure of deep burial over millions of years. Vast deposits of coal originate in former wetlands—called coal forests—that covered much of the Earth's tropical land areas during the late Carboniferous (Pennsylvanian) and Permian times. However, many significant coal deposits are younger than this and originate from the Mesozoic and Cenozoic eras.
Answer:
look it up of goog le
Explanation:
what change in gravitational force become when mass of both bodies is double and distance between them is halved
Answer:
in such condition the gravitational force will increase 16 times
Please find attached photograph for your answer.
mot o to ro ben luc 6h voi van toc toc 40 km/h
Answer:
? có thể cụ thể hơn ko
Explanation:
Seje
A burning electric bulb is a good example of a(an)... object.
2 points
illuminated
luminous
translucent
transparent
Clear selection
Can you help me answer this pls
Answer:
luminous bcz they emits light by their own and don't need other resources to emit light
A 5000 pound car sitting in the last parking space in the block a scalar or vector quantity??
Answer:
scalar
Explanation:
pounds is a unit of mass, and mass is a scalar quantity.
if it was weight (in newtons) it would be a vector.
A 5000-pound car sitting in the last parking space in the block is a scalar quantity, not a vector quantity.
What are scaler quantity and vector quantity?The scaler quantity is only the quantity having some amount of magnitude but not direction and vector quantity is that which consists of both magnitude and the direction with them.
In 5000 pound car sitting in the last parking space in the block, it has a magnitude of 5000 pounds but does not have any direction to move and it comes under the scalar quantity.
Therefore, a car has scalar quantity not vector if, a 5000-pound car sitting in the last parking space in the block.
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help me pleaseeeeeeddd
Answer:
Explanation:
a )
According to graph the object moves with constant velocity of 10 m /s during first 8 s and then its velocity changes to - 5 m /s from 8 th second upto 12 th second .
Initial displacement = 8 m
displacement during 8 s = velocity x time
= 8 x 10 = 80 m
total displacement = 88 m
b )
displacement during period from 8 th to 12 th s
= - 5 x 4 = - 20 m
total displacement after 12 s
= 88 - 20 = 68 m
c ) average speed = total distance covered during 12 s / total time
= (80 + 20) / 12
= 8.33 m /s
average velocity = total displacement during 12 s / total time
= 80 - 20 / 12
= 60 / 12
= 5 m /s .
Calculate the current passing through a conductor of resistance 4ohms. If a potential difference of 15V its ends______
Explanation:
current = velocity/resistance
I = V/R
15/4
current = 3.75A
hope this helps...
A hammer is used to hit a nail into a board. Which statement is correct about the forces at play between the nail and the hammer? The nail exerts an equal force on the hammer in the same direction. The nail exerts a much smaller force on the hammer in the opposite direction. The nail exerts an equal force on the hammer in the opposite direction. The nail exerts a much smaller force on the hammer in the same direction.
Answer:
The nail exerts an equal force on the hammer in the opposite direction.
Explanation:
The Newtons third law states that there is an equal an opposite reaction for every action. When hammer pushes the nail, the nail will push the hammer back in opposite direction. When the hammer hits a nail then nail will exert the equal and opposite force to the hammer. These both objects will exert force on each other in opposite directions.
Hello, I am BrotherEye
Answer:
Answers are
1. "The nail exerts an equal force on the hammer in the opposite direction."
2. "500 N"
3. "The iron piece exerts a force of 1 N on the magnet in the opposite direction."
4. "When mass moves closer to the point of rotation, rotational inertia decreases."
5. "The skater spins slower because his rotational inertia has increased."
Explanation:
A small cylinder is rolled along a ruler and completes two revolutions. The circumference is the distance around the outside of a circle. What is the circumference of the cylinder? A 4.4 cm B 5.2 cm C 8.8 cm D 10.2 cm
Answer; 4.4cm
Explanation: There is a ruler upon which the cylinder start from 1.4cm and reaches 10.2cm
distance traveled =10.2-1.4=8.8
since this cylinder is small so the linear distance can be approximately taked as rotational distance(as in case of point charge) so
2x2πxr =8.8
so the circumference will be 2πr=4.4cm
A glass rod acquires charge by rubbing silk cloth. The charge on the glass is due to:
(a) Friction
(b) Conduction
(c) Induction
(d) Radiation
Answer:
(a)Friction
Explanation:
It is due to friction as you are rubbing the glass rod with silk cloth
as friction occurs when 2 surfaces are rubbed against each other
Therefore it is charging by friction
5. A combination of waves is producing oscillations on a rope that is fixed at both ends and has a tension of 100 ????. The wavelength of the resulting net wave is equal to the length of the rope. If the equation for the displacement of a point on the rope is given by y(x, t) = (0.1 m) sin π x sin 12πt, where the rope begins at x = 0, x is in meters, and t is in seconds, what are the a) length of the rope, b) the speed of the waves on the rope, and c) the mass of the rope?
Answer:
a) 4 m
b) 24 m/s
c) 0.174 kg
Explanation:
a) Tension in string equation
The information given are;
The wavelength is equal to the rope length , λ = L
The tension = 100 N
The displacement of a point on the rope is y(x, t) = (0.1 m) sinπ x sin 12πt
Given that the wavelength = the length of the rope, the rope is on second harmonic
L = 2·n and the length of the wire = 2 × 2 = 4 m given the dimensions are in meters
b) Where k = 2·π/λ
v = ω/k = 12π/(2·π/λ)= (12π/2π)×λ = 24 m/s
c) f = v/λ = 24/4 = 6 Hz
[tex]f = \dfrac{\sqrt{\dfrac{T}{m/L} } }{2L} = \dfrac{\sqrt{\dfrac{100}{m/4} } }{2 \times 4}[/tex]
[tex]6 \times 8= {\sqrt{\dfrac{100}{m/4} } }[/tex]
m/4 = 100/2304
m = 0.174 kg.
prove that, s=u+v/2
please I need help
Answer:
Actually the formulae is S=(u+v/2)t
.TO explain,from average velocity=distance /time
and average velocity is u+v/2
hence using the formular
Average velocity=distance/time
distance will be=average velocity ×time
so S=(u+v/2)t
Please round 1045.2 to three significant digits
Answer:
1040
Explanation:
The rules for significant digits is that non-zero digits are significant figures. The zero in between 1 and 4 is significant because any zeroes between two significant digits are significant. Trailing zeroes if there is no decimal point are insignificant.
The number 1045.2 rounded to three significant digits would be 1040 because the rightmost zero is not a significant digit.
What are significant figures?In positional notation, significant figures refer to the digits in a number that is trustworthy and required to denote the amount of something, also known as the significant digits, precision, or resolution.
The definition of a significant digit according to the criteria is a non-zero digit. Any zeroes between two significant digits, such as the one between 1 and 4, are noteworthy. In the absence of a decimal point, trailing zeroes are not relevant.
According to the criteria for significant digits, non-zero digits are important numbers. The zero between 1 and 4 is crucial, as is any zero between two significant digits. The trailing zeroes are irrelevant if there is no decimal point.
Thus, the number 1045.2 rounded to three significant digits would be 1040.
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At what altitude the value of ‘g’ would become one fourth (¼)of the surface of the earth?
Answer:
Explanation:
For acceleration due to gravity g , the expression is
g = GM / R² , where G is gravitational constant M is mass of the earth and R is radius of the earth .
At height h , let the value of it becomes g / 4 , so
g / 4 = GM / ( R + h )²
dividing
4 = [( R+ h)² / R² ]
2 = (R + h) / R
2 = 1 + h / R
h / R = 1
h = R
So at height equal to radius of the earth , acceleration due to gravity becomes 1 /4 of value on the surface of the earth .
Water floats on a liquid called "carbon tetrachloride." The two liquids do not mix. A light ray passing from water into carbon tetrachloride has an incident angle of 45.0° and an angle of refraction of 40.1°. If the index of refraction of water is 1.33, what is the index of refraction of carbon tetrachloride?
Answer:
1.26
Explanation:
[tex]index \: of \: refraction \: = \: \ \frac{ \sin(angle \: of \: incidence) }{ \sin(angle \: of \: refraction) } [/tex]
[tex] \frac{ \sin(45.0) }{ \sin(40.1) } [/tex]
= 1.26
Refractive index is defined as the ratio of speed of light in the vacuume and in the medium.The index of refraction of carbon tetrachloride is 1.26.
Refractive index:
It is defined as the ratio of speed of light in the vacuume and in the medium.
[tex]\bold { n={\dfrac {c}{v}}}[/tex]
where
c -speed of light in vacuum
v - phase velocity of light in the medium.
It can also be calculated by the angle of refration,
[tex]\bold { n={\dfrac {sin\ i}{sin\ r}}}[/tex]
Where,
Sin i - angle of incidence = 45.0
sin r - angle of refraction = 40.1
Put the values in the formula,
[tex]\bold { n= {\dfrac {45.0}{40.1 }}}\\\\\bold { n= 1.26}[/tex]
Thereforew, the index of refraction of carbon tetrachloride is 1.26.
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Write the dirference between sl system
and cgs system
Explanation:
st system:the internationak system of measurement which i declared form internationäl convention of scientists held in france in 1960AD is Si system
CGS System:it measure in length in centimeter mass in gram time in second
Given: F = k· m. g
Solve for "k"
Answer:
[tex]F = kmg \\ k = \frac{F}{mg} [/tex]
Explanation:
F = k . m . g
=> F = k . mg
[tex] = > k = \frac{F}{mg} (ans)[/tex]
16. Two of Jupiter's Galilean moons, lo and
Europe, make a complete revolution around it
over the periods T1=1.77 days and T2 = 3.55
days. Knowing that lo revolves around Jupiter
at a distance of 421600 km, determine the
linear velocity of Europe's motion in its orbit.
Answer:
The linear velocity of europe's motion in its orbit is 7875.58 km/hr.
Explanation:
Given that,
Time period of lo = 1.77 days
Time period of europa = 3.55 days
Distance of lo from jupiter = 421600 km
We know that,
Distance of europa from jupiter = 671000 km
We need to calculate the linear velocity of europe's motion in its orbit
Using formula of velocity
[tex]v=\dfrac{d}{t}[/tex]
Where, d = distance between europa and jupiter
t = time
Put the value into the formula
[tex]v=\dfrac{671000}{3.55\times24}[/tex]
[tex]v=7875.58\ km/hr[/tex]
Hence, The linear velocity of europe's motion in its orbit is 7875.58 km/hr.
1Dyne = How many Newtons??
Answer:
answer to this question
1 × 10-5 newton
hope it helps:)
Answer:
I dyne= 1×10^-5 newtons
Explanation:
hope it will help you
Sound waves move the fastest through which medium?
Answer:
Sound travels fastest through solids.
Explanation:
This is because molecules in a solid medium are much closer together than those in a liquid or gas, allowing sound waves to travel more quickly through it. In fact, sound waves travel over 17 times faster through steel than through air.
Sound waves move the fastest through the solid. The speed of the sound wave in the liquid and gas is low,
What is sound wave?A sound wave is produced when a medium begins to vibrate. When an entity vibrates, a pressure wave is formed, which causes sound.
Solids transmit sound the fastest. Because the molecules in a solid medium are much closer together than in a liquid or gas, sound waves can move through it much faster.
Hence, sound waves move the fastest through the solid.
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The mass of objects is 4kg and it has a density of 5gcm^-3. what is the volume
Answer:
4kg×5gm^3=60
Explanation:
the object if heavy
A man stands still on a moving walkway that is going at a speed of 0.2 m/s to
the west. What is the velocity of the man according to a stationary observer?
A. 0.2 m/s north
B. 0.2 m/s west
C. 0.2 m/s South
D. 0.2 m/s east
When,a man stands still on a moving walkway that is going at a speed of 0.2 m/s to the west,then the velocity of the man according to a stationary observer would be 0.2 m/s west,Therefore, the correct answer would be option B.
What is Velocity?The total displacement covered by any object per unit of time is known as velocity. The velocity of an object is depend on the magnitude as well as the direction of the object.
the mathematical expression for velocity is given by
velocity = total displacement /time
The speed and velocity of the object are very different from each other because speed does not depend upon the direction of the moving object but velocity depends on the magnitude of speed as well as the direction of the moving object.
As per given in the problem a man stands still on a moving walkway that is going at a speed of 0.2 m/s to the west therefore from the perspective of a stationary observer the velocity of man would be 0.2 m/s towards West.
Hence the correct options for the problem would be option B.
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Please answer, it's really urgent A boy performs an experiment to measure the speed of sound. He stands 100 meters away form a large wall and claps his hands to make an echo. He claps again as soon as he was the echo, He does this ten times, each time clapping an soon as he hears the echo. The time between the first clap and the tenth echo a recorded. Why it better to time ten echoes together rather than just one echo?
Answer:
Explanation:
The speed of sound is very high . It is about 340 m /s . In one echo , it takes approximately
2 x 100 / 340
= .6 sec
In 10 simultaneous echo , it will take 6 s . It is difficult to measure .6 sec but to measure 6 s is easy and it can be made with greater precision , so we can calculate velocity of sound with great precision .
This is the reason why , instead of one echo , 10 echos are made and duration of 10 echo is measured , rather than making one echo and measuring time of one echo .