Answer:
A black hole is a region of spacetime where gravity is so strong that nothing—no particles or even electromagnetic radiation such as light—can escape from it.[1] The theory of general relativity predicts that a sufficiently compact mass can deform spacetime to form a black hole.[2][3]
The boundary of the region from which no escape is possible is called the event horizon. Although the event horizon has an enormous effect on the fate and circumstances of an object crossing it, according to general relativity it has no locally detectable features.[4] In many ways, a black hole acts like an ideal black body, as it reflects no light.[5][6] Moreover, quantum field theory in curved spacetime predicts that event horizons emit Hawking radiation, with the same spectrum as a black body of a temperature inversely proportional to its mass. This temperature is on the order of billionths of a kelvin for black holes of stellar mass, making it essentially impossible to observe directly.
Objects whose gravitational fields are too strong for light to escape were first considered in the 18th century by John Michell and Pierre-Simon Laplace.[7] The first modern solution of general relativity that would characterize a black hole was found by Karl Schwarzschild in 1916, although its interpretation as a region of space from which nothing can escape was first published by David Finkelstein in 1958. Black holes were long considered a mathematical curiosity; it was not until the 1960s that theoretical work showed they were a generic prediction of general relativity. The discovery of neutron stars by Jocelyn Bell Burnell in 1967 sparked interest in gravitationally collapsed compact objects as a possible astrophysical reality.
Black holes of stellar mass are expected to form when very massive stars collapse at the end of their life cycle. After a black hole has formed, it can continue to grow by absorbing mass from its surroundings. By absorbing other stars and merging with other black holes, supermassive black holes of millions of solar masses (M☉) may form. There is consensus that supermassive black holes exist in the centers of most galaxies.
The presence of a black hole can be inferred through its interaction with other matter and with electromagnetic radiation such as visible light. Matter that falls onto a black hole can form an external accretion disk heated by friction, forming quasars, some of the brightest objects in the universe. Stars passing too close to a supermassive black hole can be shred into streamers that shine very brightly before being "swallowed."[8] If there are other stars orbiting a black hole, their orbits can be used to determine the black hole's mass and location. Such observations can be used to exclude possible alternatives such as neutron stars. In this way, astronomers have identified numerous stellar black hole candidates in binary systems, and established that the radio source known as Sagittarius A*, at the core of the Milky Way galaxy, contains a supermassive black hole of about 4.3 million solar masses.
On 11 February 2016, the LIGO Scientific Collaboration and the Virgo collaboration announced the first direct detection of gravitational waves, which also represented the first observation of a black hole merger.[9] As of December 2018, eleven gravitational wave events have been observed that originated from ten merging black holes (along with one binary neutron star merger).[10][11] On 10 April 2019, the first direct image of a black hole and its vicinity was published, following observations made by the Event Horizon Telescope in 2017 of the supermassive black hole in Messier 87's galactic centre.[12][13][14]
Blackness of space with black marked as center of donut of orange and red gases
The supermassive black hole at the core of supergiant elliptical galaxy Messier 87, with a mass about 7 billion times that of the Sun,[15] as depicted in the first false-colour image in radio waves released by the Event Horizon Telescope (10 April 2019).[16][12][17][18] Visible are the crescent-shaped emission ring and central shadow,[19] which are gravitationally magnified views of the black hole's photon ring and the photon capture zone of its event horizon. The crescent shape arises from the black hole's rotation and relativistic beaming; the shadow is about 2.6 times the diameter of the event horizon.[12]
Schwarzschild black hole
Simulation of gravitational lensing by a black hole, which distorts the image of a galaxy in the background
Gas cloud being ripped apart by black hole at the centre of the Milky Way (observations from 2006, 2010 and 2013 are shown in blue, green and red, respectively).[20]
Distinguishing between Speed and Velocity.
Answer:
Speed: Distance per time, 400 km/h, and a scalar quantity.
Velocity: Displacement per time, 20 m/s south, and a vector quantity.
Explanation:
Hope this helps! Please mark as brainliest.
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What will be the average velocity of a body falling in free fall on Earth for 3 s?
Answer:
29.4m/s
Explanation:
Given parameters:
Time = 3s
Unknown:
Average velocity = ?
Solution:
To solve this problem, we use the expression below:
v = u + gt
v is the average velocity
u is the initial velocity = 0m/s
g is the acceleration due to gravity = 9.8m/s²
t is the time
So;
v = 0 + (9.8 x 3) = 29.4m/s
How much distance does a car travel if it is driving down the road at 50 m/s before hitting
the gas and accelerating at 3 m/s2 for 20 seconds?
Answer:
from second equation of motion
[tex]S = ut + \frac{1}{2} a {t}^{2} \\ S = (50 \times 20) + (\frac{1}{2} \times 3 \times {20}^{2} ) \\ S = 1000 + 600 \\ S = 1600 \: m[/tex]
A ‘thermal tap’ used in a certain apparatus consists of a silica rod which
fits tightly inside an aluminium tube whose internal diameter is 8mm at
0
0C. When the temperature is raised, the fit is no longer exact. Calculate
what change in temperature is necessary to produce a channel whose
cross-section is equal to that of a tube of 1mm internal diameter. (linear
expansivity of silica = 8X10-6
/K and linear expansivity of aluminium =
26X10-6
/K )
Correct question is;
A thermal tap used in a certain apparatus consists of a silica rod which fits tightly inside an aluminium tube whose internal diameter is 8mm at 0°C.When the temperature is raised ,the fits is no longer exact. Calculate what change in temperature is necessary to produce a channel whose cross-sectional is equal to that of the tube of 1mm. (linear expansivity of silica = 8 × 10^(-6) /K and linear expansivity of aluminium = 26 × 10^(-6) /K).
Answer:
ΔT = 268.67K
Explanation:
We are given;
d1 = 8mm
d2 = 1mm
At standard temperature and pressure conditions, the temperature is 273K.
Thus; Initial temperature; T1 = 273K,
Using the combined gas law, we have;
P1×V1/T1 = P2×V2/T2
The pressure is constant and so P1 = P2. They will cancel out in the combined gas law to give:
V1/T1 = V2/T2
Now, volume of the tube is given by the formula;V = Area × height = Ah
Thus;
V1 = (πd1²/4)h
V2 = (π(d2)²/4)h
Thus;
(πd1²/4)h/T1 = (π(d2)²/4)h/T2
π, h and 4 will cancel out to give;
d1²/T1 = (d2)²/T2
T2 = ((d2)² × T1)/d1²
T2 = (1² × T1)/8²
T2 = 273/64
T2 = 4.23K
Therefore, Change in temperature is; ΔT = T2 - T1
ΔT = 273 - 4.23
ΔT = 268.67K
Thus, the temperature decreased to 268.67K
a car covers at speed of 50m/s. how far it travels in 5 minutes
Answer:
15,000 m
Explanation:
[tex]speed = \frac{distance}{time} [/tex]
speed = 50 m/s
time = 5 minutes × 60
= 300 seconds
substitute the values into the formula
[tex]50 = \frac{distance}{300} [/tex]
[tex]50 \times 300 = distance[/tex]
[tex]15000 \: m = distance[/tex]
[tex]distance = 15000 \: m[/tex]
Energy energy can be transferred from one form to another we use many Indrajeet Converse in our daily life observe carefully to find these energy conversion your home make a list of any ten convert including their names along with their energy chains
Answer:
Find the list below.
Explanation:
Energy conversion imply the transformation of energy from one form to another. Examples of these conversions in my home include the following:
1. Chemical energy stored in food is converted to mechanical energy used in working(example sweeping)
2. Chemical energy stored in batteries are used to produce sound energy from the radio.
3. Electrical energy flowing through the wires are used to provide heat energy from the heating device.
4. Electric energy stored in the fan is converted to kinetic energy.
5. Chemical energy stored in petrol is converted to mechanical and electrical energies in the generator.
6. Electric energy supplied by the electric gas cooker is used to generate thermal energy after heating water.
7. Electrical energy flowing through the wires supply light energy in the bulbs.
8. Electric energy is converted to light and sound energy in the televisions.
9. Light energy from the sun is converted to chemical energy in the plants at the garden.
10. Electric energy is converted to sound and light energy in the kitchen blender.
What evidence do we have that Earth has a magnetic field surrounding the planet?
A compass works the way it does because Earth has a magnetic field that looks a lot like the one in a magnet.
What is magnetic field?The Earth's field is completely invisible, but it can be felt by a compass needle on the Earth's surface, and it reaches thousands of miles out into space.
Mathematically, the magnetic field is represented as a vector field. This vector field can be easily visualized as a collection of several vectors laid out in a grid. Each vector has a length based on the strength of the magnetic field and points in the same direction as a compass would.
This method is demonstrated by placing a grid of numerous small compasses in a magnetic field. The only distinction is that a compass does not reveal the strength of a field in this instance.
Therefore, A compass works the way it does because Earth has a magnetic field that looks a lot like the one in a magnet.
To learn more about magnetic field, refer to the link:
https://brainly.com/question/14848188
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Using the information given, find the Atomic Mass of the unknown element: 12 PROTONS, 12 NEUTRONS, 12 ELECTRONS
Answer:
A. 12
Explanation:
During the formation of the aurora borealis, the electrons in an atom experience a change in energy levels. Which statement about this change is accurate?
First, the electron releases energy to move to a higher energy level.
First, the electron absorbs energy to move to a higher energy level.
First, the electron absorbs energy to move to a lower energy level.
First, the electron releases energy to move to a lower energy level.
Answer:
They are deflected as Earth’s magnetic field exerts force on them.
Explanation:
(Not for cheating, Just to help)
As solar wind approaches Earth, what happens to the charged electrons?
They are absorbed as Earth’s magnetic field exerts force on them.
They grow stronger as Earth’s magnetic field exerts force on them.
They grow weaker as Earth’s magnetic field exerts force on them.
They are deflected as Earth’s magnetic field exerts force on them.
First, the electron absorbs energy to move to a higher energy level.
The speed you read on a speedometer is ____.
Answer:
[tex]\leq 40[/tex]
Explanation:
So if you’re going 40mph, your speedometer may read up to 50.25mph - but it can never read less than 40mph. In order to stay within the law, carmakers calibrate their speedometers to slightly overreport their vehicles' speeds.
plzz help.me with both questions
Explanation:
Primary cell
1. They are non-rechargeable.
2. The energy density of primary cells is more.
3. The internal resistance of primary cells is more.
4. Example : Zinc-Carbon cell.
Secondary cells
1. They are rechargeable cells.
2. The energy density of secondary cells is less.
3. The internal resistance of secondary cells is less.
4. Example : Car batteries
Current :
The flow of electric charge per unit time is called electric current. It can be given by the formula as follows :
[tex]I=\dfrac{q}{t}[/tex]
The SI unit of electric current is Ampere.
1 Ampere is defined as the current that flows with the electric charge of one Coulomb per second (C/s).
Pls Solve this!!!Im giving 20 points and Brainliest to the one who answers first. HELP ME PLEASE!!!!!!!!
Answer:
i) 2Mg + O₂ + Δ Heat → 2MgO + Δ Energy
ii) The aqueous solution does not change in the color of the blue litmus paper and the blue litmus paper remains blue in color
The aqueous solution formed using the product (MgO) turns the red litmus paper blue
Explanation:
i) Magnesium easily burns in air or oxygen when heated to form a white powder of magnesium oxide. The burning (reaction) of magnesium in air is an exothermic reaction that involves the release of heat and light
The burning of magnesium wire is given by the following chemical reaction;
2Mg + O₂ + Δ Heat → 2MgO + Δ Energy
ii) When magnesium oxide is mixed with water if forms magnesium hydroxide Mg(OH)₂ as shown in the following chemical reaction;
MgO + H₂O → Mg(OH)₂
Magnesium hydroxide is basic and therefore it will turn red litmus paper blue and it does not change the color of the blue litmus paper.
1. Place these unknown pH test papers in order from most acidic to most alkaline.
А в
C D
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14
pH color chart
A. Paper D. paper C, paper B, paper A
B. Paper B, paper A, paper C, paper D
C. Paper C, paper D, paper A, paper B
D. Paper D, paper C, paper A, paper B
Answer: B
Explanation: look at the chart, easy
Answer:
D
Explanation:
What is osomsis and diffusion
Answer:
Osmosis is the movement of solvent particles across a semipermeable membrane from a dilute solution into a concentrated solution. ... Diffusion: Diffusion is the movement of particles from an area of higher concentration to lower concentration. The overall effect is to equalize concentration throughout the medium.
where should i graph the distance in a distance time graph
Answer:
Distance in Y axis and Time in axis
Answer:
the distance should be on the Y axis (vertical) and the time should be on the X axis (horizantial)
If a car traveled 60 m in 30 s, what is the velocity?*
Answer:
6.56168
Explanation:
In the picture above, if the cue stick strikes the 0.2-kg cue ball with a force of 1.1 N, what will be the acceleration of the cue ball?
Answer:
0.55 m/s².
Explanation:
From the question given above, the following data were obtained:
Mass (m) of ball = 2 Kg
Force (F) applied = 1.1 N
Acceleration (a) =?
Force (F) is defined as the product of mass (m) and acceleration (a). Mathematically, the force (F) can be represented as:
Force (F) = mass (m) × acceleration (a)
F = ma
With the above formula, we can calculate the acceleration of the ball as follow:
Mass (m) of ball = 2 Kg
Force (F) applied = 1.1 N
Acceleration (a) =?
F = ma
1.1 = 2 × a
Divide both side by 2
a = 1.1 / 2
a = 0.55 m/s²
Therefore, the acceleration of the ball is 0.55 m/s²
Imagine that person B is more massive than person A in the picture above.
If they push off of each other with the same amount of force, who will
have the greater acceleration? What law are you applying? Explain how
that law is being applied.
What are natives from Cambodia called
Answer:
Khmer people make up 90% of the Cambodian population, followed by Vietnamese (5%), with the balance being Chinese, Cham (mostly a muslim people) and indigenous ethnic groups sometimes called Khmer Loeu
Explanation:
Answer:
Khmer
Explanation:
How can magnets cause objects to have kinetic energy?
Answer:
this has to do with the drop in voltage, or potential as electrons traverse the material .
Which tool can easily separate sand and iron filings?
O oil
O magnet
O water
Answer:
A magnet would be the answer
How can we find velocity?*
Answer: discplacement/change in time = average velocity.
Explanation:
There is a formula for velocity which is given above
A subduction zone is where one plate is pulled under the edge of another and occurs in convergent plate boundaries. Which type of crusts are involved in the subduction zone?
a. continental-continental
b. continental-oceanic
c. oceanic-oceanic
Answer:
b. Continental-oceanic
Explanation:
The Earth's crust has been divided into a series of plates. These plates move at a different rate or speed in different directions.
These plates are divided by the boundary between them which are of three types: convergent, transform and divergent.
The convergent boundaries are the one which moves toward each other and the based on the crust they are of three types: continent-continent, ocean-ocean and ocean-continent.
In ocean-continent boundaries, the oceanic plate is denser compared to the continental plate is lighter as a result of which during the process of subduction the oceanic plate sinks beneath the continental plate towards the mantle and melts.
Thus, Option-B is the correct answer.
What caused the original creation of the Universe? How do we find out?
Which term is also known as a "rate of change"? * a motion b distance c reference point d speed
Acceleration is the answer.............
Between ball B and ball C, ball ____ has LESS potential energy because ___
a: c;its mass is greater
b: b;its mass is smaller
c: c; its mass is smaller
d: b;its mass is greater
Answer: b
Explanation:
Ec= (1/2)m × v^2
By the formula, you can see that the bigger the mass, the bigger the Cinetic Energy.
b: b; its mass is smaller
Between ball B and ball C, ball B has LESS potential energy because its mass is smaller.
A potential energy, stored energy that depends upon the relative position of various parts of a system. A spring has more potential energy when it is compressed or stretched.
Potential energy is given by formula.
[tex]P.E= m*g*h[/tex]
Since, P.E is directly proportional to mass. Thus, the ball having smaller mass will have the less P.E.
Thus, option b is correct.
Learn more:
brainly.com/question/13584911
Tyler is in downtown San Antonio entertaining the tourists with amazing feats of physics. He carries a nickel
(mass of 5.0 grams) up to the top of the Tower of the Americas and places it on the edge of the observation
deck, a height of 124 meters. Tyler pushes the nickel off the edge of the Tower, and then tells the tourists
that he will be able to calculate the velocity of the nickel just before it hits the ground. What will be the
nickel's velocity?
Answer:
The velocity of the nickel just before it hits the ground is approximately 49.3 m/s
Explanation:
In order to calculate the velocity of the nickel just before it hits the ground, we recall the kinematic equation of motion, v² = u² + 2·g·h, where the variables of the equation are defined as follows;
v = The velocity of the nickel just before it hits the ground after it is pushed off the observation deck
u = The initial velocity of the nickel just before it is pushed off the observation deck = 0 m/s
g = The acceleration due to gravity = 9.8 m/s²
h = The height from which he nickel is pushed off the edge = 124 m
Substituting the given values and the constant, "g", we have;
v² = 0² + 2 × 9.8 × 124 = 2,430.4
v = √2,430.4
Using a graphing calculator, we have;
v = √2,430.4 = 14·√(62/5) ≈ 49.3
The velocity of the nickel just before it hits the ground = v ≈ 49.3 m/s.
The refraction of a wave is caused by a
change in
A. amplitude.
B. frequency
C. speed.
D. wavelength.
Answer:
C- speed
Explanation:
Refraction is the bending of waves caused by a change made in the speed which allows it to move from one medium to another.
Answer:
C. Speed of light
Explanation:
Refraction of light is caused due to change in the speed of light in different mediums. Refraction is the bending of the path of a light wave as it passes from one material into another material. The refraction occurs at the boundary and is caused by a change in speed of light wave upon crossing the boundary
What are the advantages of two-dimensional art forms like photographs?
What are the limitations of two-dimensional art forms like photographs?
Answer:Two dimensional forms can create the illusion of 3 dimensional shapes and spaces.
Explanation:
When a wire with a current is placed in a magnetic field, electrical energy is transformed into mechanical energy
Please select the best answer from the choices provided
T
F
Answer:
TRUE
Explanation:
When a wire with a current is placed in a magnetic field, electrical energy is transformed into mechanical energy. The transformation happens when the magnetic field produced by the current causes the wire to move.
