Explain why nuclear fusion takes place only in the center of stars

Answers

Answer 1
 A star is born when atoms of light elements are squeezed under enough pressure for their nuclei to undergo fusion. All stars are the result of a balance of forces: the force of gravity compresses atoms in interstellar gas until the fusion reactions begin. And once the fusion reactions begin, they exert an outward pressure. As long as the inward force of gravity and the outward force generated by the fusion reactions are equal, the star remains stable. Clouds of gas are common in our galaxy and in other galaxies like ours. These clouds are called nebulae. A typical nebula is many light-years across and contains enough mass to make several thousand stars the size of our sun. The majority of the gas in nebulae consists of molecules of hydrogen and helium--but most nebulae also contain atoms of other elements, as well as some surprisingly complex organic molecules. These heavier atoms are remnants of older stars, which have exploded in an event we call a supernova. The source of the organic molecules is still a mystery. 

STAR BIRTHS are started when the interstellar matter in gas clouds, such as the Eagle Nebula shown here, compresses and fuses. Irregularities in the density of the gas causes a net gravitational force that pulls the gas molecules closer together. Some astronomers think that a gravitational or magnetic disturbance causes the nebula to collapse. As the gases collect, they lose potential energy, which results in an increase in temperature. As the collapse continues, the temperature increases. The collapsing cloud separates into many smaller clouds, each of which may eventually become a star. The core of the cloud collapses faster than the outer parts, and the cloud begins to rotate faster and faster to conserve angular momentum. When the core reaches a temperature of about 2,000 degrees Kelvin, the molecules of hydrogen gas break apart into hydrogen atoms. Eventually the core reaches a temperature of 10,000 degrees Kelvin, and it begins to look like a star when fusion reactions begin. When it has collapsed to about 30 times the size of our sun, it becomes a protostar. When the pressure and temperature in the core become great enough to sustain nuclear fusion, the outward pressure acts against the gravitational force. At this stage the core is about the size of our sun. The remaining dust envelope surrounding the star heats up and glows brightly in the infrared part of the spectrum. At this point the visible light from the new star cannot penetrate the envelope. Eventually, radiation pressure from the star blows away the envelope and the new star begins its evolution. The properties and lifetime of the new star depend on the amount of gas that remains trapped. A star like our sun has a lifetime of about 10 billion years and is just middle-aged, with another five billion years or so left.

Related Questions

Why does the area swept by a planet in a given period of time remain constant even as the planet speeds up and slows down

Answers

A planet orbiting a star in a eclipse and sometimes it is closer to the star but sometimes it is farther. When it is closer the gravity on the planet from the star is stronger and it speeds up. The area the planet sweeps over is equal because when it speeds up the length covered along the orbital path is greater, but it is also closer to the star, and that dimension is decreased. 
The planet speeds up when it's closer to the sun, and sweeps out a short fat triangle every hour. It moves slower when it's farther from the sun, and sweeps out a long skinny triangle every hour. The triangles have equal areas.

The only way I know to explain WHY this happens is:. That's how gravity works.

By the time you finish a couple of semesters of college Physics, you'll be able to take Newton's laws of gravity and motion, add some geometry and some calculus, stir well, and show why the planets must follow Kepler's laws.

The variable that you change during an experiment is called what type of variable?

Answers

The independent variable 
Independent is the affect of a dependent variable
control keeps everything the same

The Power Rocket coaster track is 3,265 feet and the ride is 90 seconds long. What is the speed of the coaster in feet per second?

Answers

Not sure if you're in FLVS or not but, the answer should be 36. I'm doing the same assignment. Pretty sure all you have to do is divide 3,265 and 90. Hope I could help you out.

When discussing what makes a material a good conductor you say, "They must
resist neutron flow."
readily accept electron flow."
readily accept neutron flow."
resist electron flow."

Answers

readily accept electron flow            b. right answer 


Answer:

readily accept electron flow."

Explanation:

As we know that electric current is defined as rate of flow of electric charge which is basically due to flow of electrons

So here we can say that

[tex]i = \frac{dq}{dt}[/tex]

now we know that conductors are defined as good conductors when they do not resist the flow of charge

which means a good conductor will easily conduct the electric current through it.

So here correct answer will be

readily accept electron flow."

Which of the following is not a characteristic of a creative person

A.Expertise
B.Extrinsic motivation
C.A ventures ome personality
D.Imaginative thinking skills

Answers

It is B by process of elimination.

Extrinsic motivation is not a characteristic of a creative person. Hence, option (B) is correct.

What is extrinsic motivation?

The psychological phenomena in which people engage in particular behaviors as a result of rewards from outside sources is known as "extrinsic motivation."

The practice of operant conditioning, a method of behavior modification that makes use of extrinsic motivators—or stimuli like rewards and punishments to motivate particular actions and their repetition, is based on this idea. Both intangibles and extrinsic motivators are possible.

Examples of extrinsic motivation are :

CompensationAdvancementPraiseRewardsVisibilityConflict avoidanceMutual Respect

Therefore, the extrinsic motivation is not a characteristic of a creative person. So, option (B) is correct.

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What is the main difference between protons and neutrons?

A.Protons have a much smaller mass than neutrons.
B.Protons have a much larger volume than neutrons.
C. Protons have an electrical charge, but neutrons have no charge.
D. Protons make up the nucleus, but neutrons orbit around the nucleus.

Answers

Answer:

C. Protons have an electrical charge, but neutrons have no charge.

Explanation:

Protons and neutrons both are parts of nucleus and they stay inside the nucleus due to large nuclear force between them

Mass of proton and mass of neutron is almost same or in more precisely we can say that neutrons are slightly heavy than protons

mass of neutrons is 1.008 amu while mass of protons are 1.007 amu.

the main different between them is that protons are positively charged and their charge is same as that of charge of electron

[tex]q_{proton} = 1.6 \times 10^{-19} C[/tex]

while neutrons are electrically neutral and they do not have any charge on them.

so correct answer will be

C. Protons have an electrical charge, but neutrons have no charge.

Answer:

c

Explanation:

A hot air balloon is ascending at a rate of 7.5m/s when a passenger drops a camera. If the camera is 25m above the ground when it is dropped, how much time does it take for the camera to reach the ground, and what is the velocity just before it lands?

Answers

A hot air balloon is ascending at speed of 7.5 m/s when a passenger drops a camera. If the camera is 25 m above the ground when it is dropped, it will take the object 3.15 seconds to reach the ground.

What is speed?

The speed of an object is the magnitude of the change of its position over time or the magnitude of the change of its position per unit of time; it is thus a scalar quantity.

The time it takes for an object to reach a certain level given the distance and the initial velocity can be calculated through the equation,

   d = V₀t + 0.5*gt²

Where d is the distance, V₀ is the initial velocity, g is the acceleration due to gravity and t is time. Substituting the known values from the given above,

  25 = (-7.5)(t) + 0.5(9.8 m/s²)(t²)

The value of t from the equation 3.15 s

A hot air balloon is ascending at speed of 7.5 m/s when a passenger drops a camera. If the camera is 25 m above the ground when it is dropped, it will take the object 3.15 seconds to reach the ground.

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The heating element of an electric oven is designed to produce 5.0 kw of heat when connected to a 220 v source. what must be the resistance of the element?

Answers

The answer is 9.86 ohm

The resistance of an electric oven's heating element that produces 5.0 kW of heat when connected to a 220 V source must be 9.68 ohms.

To determine the resistance of the heating element that produces 5.0 kW of heat when connected to a 220 V source, we use the formula for electrical power (P): P = V^2 / R, where P is power, V is voltage, and R is resistance. Rearranging the formula for resistance gives us R = V^2 / P.

Substituting the given values, we get R = (220 V)^2 / (5.0 kW), which can be further simplified as R = 48400 V^2 / 5000 W = 9.68

Therefore, the resistance of the heating element must be 9.68 ohms.

You drop a rock off the top of a 100m tall building. How long does it take to hit the ground?

Answers

how heavy is the rock? comment and i will tell you answer

NEED THIS ANSWERED ASAP!!!! IN MIDDLE OF TEST RN HELP PLZ
Barry is conducting an experiment and rolls a tennis ball down a ramp. Which best describes the motion of the tennis ball?

A)It does not exhibit projectile motion and follows a straight path down the ramp.
B)It does not exhibit projectile motion and follows a parabolic path down the ramp.
C)It exhibits projectile motion and follows a straight path down the ramp.
D)It exhibits projectile motion and follows a parabolic path down the ramp.

Answers

The correct answer for this question would be option A. When Barry is conducting an experiment and rolls a tennis ball down a ramp, the statement that best describes  the motion of the tennis ball is that, it does not exhibit projectile motion and follows a straight path down the ramp. Hope this helps.
The answer should be A, it does not exhibit projectile motion and follows a straight path down the ramp. 

It's not in the air or anything so we definitely know it's not a projectile :D.

Which force is responsible for making fusion possible in the sun?

Answers

what are the answer choices, can you tell me the please?

Answer: Strong Nuclear Force is responsible for making fusion possible in the sun .

Explanation:

Fusion reaction is basically the result of the interplay of two opposing forces

1. Attractive Strong Nuclear Force

2. Repulsive coulomb force

Strong nuclear force is a short range force while its magnitude is much greater than the coulomb force . When two nuclei approach each other coulomb force of repulsion between the nuclei (proton-proton repulsion) acts between the nuclei but due high speed as the nuclei come closer strong nuclear force of attraction come into play which has magnitude much more larger than the coulomb force .

             The strong force grows rapidly once the nuclei are close enough, and the fusing nucleons can essentially "fall" into each other and the result is fusion and net energy produced. Thus it is the presence of Strong Nuclear Force which makes the fusion possible .

A car making a 111-km journey travels 41 km/h for the first 55.5 km. how fast must it go during the second 55.5 km to average 51 km/h?

Answers

over 55.5km v = 41km/h
start by solving total time (tt) = distance (d) / v, where d = vt
tt = 111km/51km/h = 2.18h
Now let's see it the first half in t plus the second half in t = 2.18h
t1 + t2 = 2.18h
(d1/v1) + (d2/v2) = 2.18h
(55/41) + (55/v2) = 2.18h
1.34h + 55/v2 = 2.18h
55/v2 = 2.18 - 1.34
55/v2 = 0.88
v2 = 55/0.88 = 62.5km/h

Almonds cost $3.49 per pound. A bag of almonds costs $6.95. to the nearest whole pound, about how many pounds of almonds are in the bag?

Answers

The hint in this problem is in the word "about" or approximately how many pounds.

So we could find the solution by estimation through rounding off.

 

We know that almonds cost about 3.50 per pound and a bag costs about $7.00.

Dividing 7 by 3.50 per pound, will give us $7 ÷ $3.50 = 2 pounds.

The answer is 2 pounds.

Answer:2 pounds of almonds are in the bag.

Explanation:

According to question ,pounds of almonds in $3.49 = 1 pound

Then pound of almond for $1 = [tex]\frac{1}{3.49} pounds[/tex]

Pounds of almond which cost $6.95:

[tex]\frac{1}{3.49}\times 6.95 pounds=1.9914 pounds\approx 2 pounds[/tex]

2 pounds of almonds are in the bag.

What is the goal of the UK government in terms of carbon dioxide and energy use?
This is for earth science

Answers

Answer:

Reducing CO2 emission to maximum extent and saving energy

Explanation:

The present energy policy of UK is set out in the Energy White Paper of May 2007 and Low Carbon Transition Plan of July 2009. It was led by the Department of Energy and Climate Change, and after that headed by Amber Rudd. The current focus of policy are on the reformation of electricity market, rolling out smart meters and improving the energy efficiency of the UK building stock through the Green Deal in which CO2 emission is on top priority.

Why are some objects heavier than others?

Answers

Some objects are heavier then others because they have more mass. Exp: A bowling ball has more mass then that of a feather. A person has more mass then that of a bowling ball. And so on… 

Here's a quote to help! 

"Galileo discovered that objects that are more dense, or have more mass, fall at a faster rate than less dense objects, due to this air resistance. A feather and brick dropped together. Air resistance causes the feather to fall more slowly." 

A system releases 680 kj of heat and does 150 kj of work on the surroundings.what is the change in internal energy of the system?

Answers

I need a answer choice

The force that is most responsible for the stability of the atomic nucleus is:
A.) gravityB.)  electromagnetismC.)  strong nuclear force D.)  weak nuclear force

Answers

I think it’s answer C

Answer: Option (C) is the correct answer.

Explanation:

Nucleus of an atom consists of protons and neutrons. Whereas electrons revolve around the nucleus of the atom.

Protons are positively charged, neutrons have no charge and electrons are negatively charged. So, like charge of protons tend to oppose each other and as a result, electrostatic force of repulsion occurs.

This electrostatic force of repulsion is overcome by strong nuclear force which helps in binding of protons and neutrons into the nucleus.

Thus, we can conclude that the force that is most responsible for the stability of the atomic nucleus is strong nuclear force.

a small airplane flies at a velocity of 145 km/h toward the south as observed by a person on the ground. The airplane pilot measures an air velocity of 172 km/h an hour. What is the velocity of the wind that affects the plane?

Answers

We apply the equation for the velocities adddition
[tex]V=V(plane)+V(wind)[/tex]
From this equation we obtain the velocity of wind
[tex]172=145+V(wind)[/tex]
[tex]V=172-145 =27 (km/h)[/tex]
The air velocity is bigger for the pilot of the plane because the speed of the plane adds with the speed of the wind.

I NEED THIS CORRECT!!
Bases turn litmus paper what color?

Answers

Red Litmus turns blue under bases and Blue litmus paper turns red under acidic conditions.

An airplane flies with a constant speed of 840 km/hr. How far will go in 270 min

Answers

It would be 3780 km... hope this helps and have a great day<3 !!!!

"what scientific principle is the mercury barometer based on"

Answers

barometers with mercury measure air pressure. when the air pressure is high the mercury rises

Which of these helps you understand what people are saying to you? A. Interrupting them B. Looking away while they're speaking C. Thinking about how you'll respond D. Thinking about what they're saying

Answers

i believe the answer is  D. Thinking about what they're saying
Interrupting them will make them unable to finish their full message/thought to you. Looking away while they're speaking will make you reduce your attention and unable to process the information properly. Thinking about how you'll response also limit your attention to them and could make you cloud your opinion and misinterpret what's they're saying.
d                  ...................................

Lavoisier made an important contribution to chemistry by _____.

coining the term "atom"
developing the law of multiple proportions
developing the law of conservation of matter
developing the atomic theory of matter

Answers

developing the law of conservation of matter
by making the law of matter witch is matter can not be made or destored 

If the mass of an object is doubled, it's gravitational force will:

Answers

the gravitational force will double as well because
F=mg

The dependent variable, or the one the response is measured in, is _______


amount of friction
Initial height
speed

Answers

amount of friction is the answer.
amount of friction because its the opinion

What was the physical principle used by edwin hubble to demonstrate that the "spiral nebulae" are very distant and large?

Answers

The physical principle used by Edwin Hubble to demonstrate that the "spiral nebulae" are very distant and large was the inverse-square law of light. The Cepheid variable stars in the spiral nebulae obey a period-luminosity relation; by measuring the period of a Cepheid star, its average luminosity can be determined, and then, by comparing this with its average apparent brightness, its distance can be calculated.

Water flows over a section of niagara falls at a rate of 6.00 ´ 105 kg/s and falls 50.0 m. what is the power dissipated by the waterfall?

Answers

The answer is: PE lost every second = mgh = 1.2x10^6 * 9.81 * 50 = 5.89x10^8J So, Power = 5.89x10^8W

How does the bohr model represent electrons around the central nucleus why think of the spectra?

Answers

In the Bohr model the electrons move around the central nucleus on certain specified circular trajectories. On these trajectories the wave associated with the electron has to be a standing wave, that is a closed wave (the beginning of the wave has to connect with the end of the wave). Because of this condition (of standing wave) only certain trajectories are allowed. When the electrons jumps from one allowed trajectory to another it emits (or absorbs) a photon of a certain (given) frequency. (If the electrons jumps on a lower orbit it emits a photon). Because there are allowed only certain trajectories, this gives (on electron jumps) only certain alowed frequencies. We say that the spectra is discrete.
  

At room temperature table salt is a solid and mercury is a liquid. What conclusion can you draw about the melting points of these substances?

Answers

Salt has a higher melting point than Mercury. 

What are the four layers of oceanic crust from top to bottom?

Answers

Oceanic, Crust, Geolific, techtonic

Oceanic, Crust, Geolific, techtonic are the four layers of oceanic crust from top to bottom.

what are oceanic crust ?

Oceanic crust is nothing but the part of the Earth's crust which makes up the seafloor which is  thinner, denser, and simpler in structure than the continental crust; it is  younger, on average; from its birth at a mid-ocean ridge to its end at a subduction zone.

The oceanic crust fragments are sometimes become stranded high and dry on top of a continent; both Continental Crust together  constitute the Earth Crust, yet they are completely distinct in composition, thickness and geological history.

The Oceanic Crust exists at the bottom of all Oceans, filling the spaces between the portions of Continental Crust, its density and thickness, plunges below the edge of the continental plate into the subduction zones.

This causes formation of  a new ocean plate to accommodate displacement of continents and replace the plate that is destroyed by subduction.

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The mixture you separated was a mixture of iron filings, sand, and salt. Based on your understanding of matter, is this mixture a homogenous mixture or heterogenous mixture? How do you know? Question 1 options: homogenous mixture-the parts are uniformly mixed homogenous mixture-the parts are not uniformly mixed heterogenous mixture-the parts are not uniformly mixed heterogenous mixture-the parts are uniformly mixed What do Homers epics reveal about Greek culture?A. the values of the ancient GreeksB. the activities of Greek sea tradersC. the beliefs of the ancient DoriansD. the origins of major Greek cities Consider this theme:Appearances can be deceiving.Which excerpt from Frankenstein best supports this theme?A. "I have good dispositions; my life had been hitherto harmless, and, in some degree, beneficial; but a fatal prejudice clouds [people's] eyes, and where they ought to see a feeling and kind friend, they behold only a detestable monster."B. "I was benevolent and good; misery made me a fiend. Make me happy, and I shall again be virtuous."C. "Cursed be the day, abhorred devil, in which you first saw light! Cursed (although I curse myself) be the hands that formed you! You have made me wretched beyond expression."D. I knew well, therefore, what would be my father's feelings; but I could not tear my thoughts from my employment. What reaction would be the chemical equation 2H2O->2H2+O2 represent? A.decomposition of water b. Formation of water c. Combustion of water d. Replacement of water Abraham Lincoln's "A House Divided" speech is historically significant because in it he declares war on the South. The strong efforts to maintain the integrity of the jewish family across generations is illustrated in the presence of In hess and pullen s (1994) study of impression formation it was found that when negative information was provided after an initial positive portrayal of a person, older adults It took a cheetah 45 minutes to run from Jungle A to Jungle B. The average speed for the trip was 80 km/h. Find the distance between the two jungles. Rewrite the sentence to eliminate ambiguous, remote, or broad reference.Since the car drips oil on the driveway, put a piece of cardboard under it. Compare the words strand and sprang. How are they alike? How are they different? Californian artist Joan Brown used this painting technique, created by applying thick layers of paint to a surface. Sam opened a savings account with an initial deposit of $2,000. Since then, he has never made any other deposits or withdrawals. His savings account earns 0.4% interest monthly and an annual bonus of 1.5% interest. Which equation gives the approximate amount, A(x), he has in his savings account as a function of x, the number of years since his initial deposit?A(x) 2,000 + (1.059)x3A(x) 2,000(1.019)x2A(x) 2,000(1.065)xA(x) 2,000(1.059)x2 Which process is similar to binary fission? Daniel dives into a swimming pool. The height of his head is represented by the function h(t) = -8t(squared) - 28t + 60, where t is the time in seconds and h(t) is the height of his head, in inches. How many seconds will it take for Daniel's head to reach the surface of the pool? The lines below express a belief recited by followers of Islam. "All praise is due to ALLAH alone, Lord of all the worlds. The Gracious, the Merciful. Master of the day of Judgment." In which of the following do these lines appear? Bible Qur'an Sutras Torah Nonvolatile in the context of data storage means ________________. a. the data can't be changed in a data warehouse. b. the data can only be changed by users. c. the data can only be changed by it professionals. d. the data can't be changed in the source system Question 8(Multiple Choice Worth 5 points)(LC)Read the following sentence and answer the question that follows.The ancient Greeks developed the concept of participatory democracy, but they also practiced slavery, denied political rights to women, and __________.Which phrase best completes the sentence above? wars of conquest waged wars of conquest were waging wars of conquest were a people who waged wars of conquest Jocelyn has 6 birds. Their mean age is 10. The mode is 8. What might their ages be? _____ believe that no one thing is intrinsically good.a. hedonistsb. deontologistsc. relativistsd. teleologistse. pluralists Masters and johnson estimated that half of all married couples experience a _______ sexual problem at some point in their marriage. Steam Workshop Downloader