Why does the rotation rate increase as an interstellar cloud collapses?
Maintaining constant angular momentum as the cloud shrinks requires that its rate of rotation increase because angular momentum depends on the product of rotation rate and radius.)
Which of the following is most important in causing a cloud of gas to collapse to form a star and planets?
Which of the following is most important in causing a cloud of gas to collapse to form a star and planets? Gravity pulls all the gas inward.
What triggers the gravitational collapse of material inside a molecular cloud?
What triggers the gravitational collapse of material inside a molecular cloud? A passing shock wave. What eventually halts the slow contraction of a newly forming star? Nuclear fusion.
Which of the following must be occurring in order for a molecular cloud to collapse and form stars?
Which of the following must be occurring in order for a molecular cloud to collapse and form stars? The buildup of thermal energy in a collapsing gas cloud leads to thermal pressure that can halt the gravitational collapse.
What does conservation of momentum say about a collapsing gas cloud?
Conservation of angular momentum, the same law that causes a skater to spin faster as they pull their arms closer to their body, causes the collapsing cloud to spin faster as it gets smaller.
What happens to the angular momentum of a collapsing cloud as it turns into a star?
As a star forming cloud begins to contract, the rotation rate must increase, because angular momentum is conserved. In general, a big, slowly rotating system will turn into a small, rapidly rotating system. The collapse amplifies the rotation rate.
What forces are responsible for the collapse of an interstellar cloud?
The law of universal gravitation says that all matter attracts all other matter, and Newton recognized a major consequence of that law: clouds of gas will tend to fragment and collapse as a result of their own gravity. This is the basic mechanism responsible for the formation of new stars from interstellar gas clouds.
What condition is necessary in an interstellar gas cloud for it to begin collapsing?
What condition is necessary in an interstellar gas cloud for it to begin collapsing? The inward pull of gravity must be stronger than the outward push of thermal pressure. The buildup of thermal energy in a collapsing gas cloud leads to thermal pressure that can halt the gravitational collapse.
Which factors resist the collapse of a cloud?
Cards
| Term What does star formation generally occur from? | Definition the cores of giant molecular clouds |
|---|---|
| Term What are the four factors that resist the collapse of a cloud? | Definition 1. thermal energy (pressure) 2. magnetic fields 3. rotation 4. turbulance |
| Term What is another word for rotation? | Definition angular momentum |
•Apr 1, 2009
What slows down the contraction of a star-forming cloud when it makes a protostar?
Conclusion: Hence, trapping of thermal energy inside the protostar slows down the contraction of a star-forming cloud when it makes a protostar.
What happens when clouds collapse?
A cloud may start with any size or shape, and different clumps of gas within the cloud may be moving in random directions at random speeds. When the cloud collapses, these different clumps collide and merge, resulting in a flattened rotating disk.
How did the cloud’s rotation rate change as the cloud collapsed to smaller and smaller radii?
Angular Momentum All clouds rotate, at least a little, due to gravitational shearing in the galaxy's disk. And if a cloud rotates, it has angular momentum: L ~ mrv. And remember that angular momentum is conserved. So if a rotating cloud collapses (r gets smaller) than it must spin faster (v gets bigger).
What forces are responsible for the collapse of an interstellar cloud quizlet?
Terms in this set (47) Battle between pressure of heated gas and gravity. Gravity tries to squeeze an interstellar cloud into an even more compact form while the collapse and in-fall of the gas converts gravitational energy into the gas pressure, thereby slowing down the collapse.
What stops the collapse of protostars?
A protostar stops collapsing when nuclear fusion begins in its center.
What prevents an interstellar cloud from just collapsing?
Heat pressure: If interstellar gas is warm enough, this pressure will prevent gravity from causing fragmentation and collapse.
What can trigger the collapse of a molecular cloud quizlet?
What can cause a molecular cloud to collapse? Collisions with other molecular clouds, space winds, gravitational interaction with other nearby stars, the explosion of a nearby star or the cloud can collapse under its own weight.
What causes a nebula to collapse?
The dust and gases in a nebula are very spread out, but gravity can slowly begin to pull together clumps of dust and gas. As these clumps get bigger and bigger, their gravity gets stronger and stronger. Eventually, the clump of dust and gas gets so big that it collapses from its own gravity.
What happens to the rotation of a molecular cloud as it collapses to form a star?
What happens to the rotation of a molecular cloud as it collapses to form a star? The rotation rate increases and results in a disk of material around a protostar.
What does a collapsing cloud do as it shrinks?
However, the nebular theory predicts that a cloud will rotate rapidly once it shrinks to a relatively small size. What physical law explains why a collapsed cloud will rotate rapidly? The nebular theory also predicts that the cloud should heat up as it collapses.
Why does the gas cloud collapse?
Intergalactic space is filled with clouds of gas (mostly H + He) and dust known as molecular clouds. These clouds are supported against gravitational collapse by their thermal pressure, but if the clouds get too big massive, gravity wins and they can start to collapse. This is the first step towards star formation.
What is the most common cause of a molecular cloud’s collapse?
What can cause a molecular cloud to collapse? Collisions with other molecular clouds, space winds, gravitational interaction with other nearby stars, the explosion of a nearby star or the cloud can collapse under its own weight.
What role does conservation of angular momentum play in nebular theory?
Conservation of angular momentum rotational motion is conserved Our Solar System formed from a giant, swirling cloud of gas & dust. The nebular theory holds that our Solar System formed out of a nebula which collapsed under its own gravity.
Which process is required to allow a gravitationally collapsing gas cloud to continue to collapse?
Which process is required to allow a gravitationally-collapsing gas cloud to continue to collapse? The cloud must radiate away much of its thermal energy.
Why do molecular clouds collapse quizlet?
What can cause a molecular cloud to collapse? Collisions with other molecular clouds, space winds, gravitational interaction with other nearby stars, the explosion of a nearby star or the cloud can collapse under its own weight.
What caused the solar nebula to collapse?
The Sun and the planets formed together, 4.6 billion years ago, from a cloud of gas and dust called the solar nebula. A shock wave from a nearby supernova explosion probably initiated the collapse of the solar nebula. The Sun formed in the center, and the planets formed in a thin disk orbiting around it.
What slows down the contraction of a star forming cloud when it makes a protostar?
Conclusion: Hence, trapping of thermal energy inside the protostar slows down the contraction of a star-forming cloud when it makes a protostar.
What slows down the contraction of a cloud into a star-forming a protostar?
The temperature in the core of the protostar is hot enough that the thermal pressure becomes strong enough to slow the collapse down to a much slower contraction.
What is the effect of conservation of angular momentum when nebular contraction starts?
Nebular Theory: Our solar system evolved from a contracting nebula. Under the influence of its own gravity, the nebula contracts. As it contracts, it spins faster and faster, much like an ice skater who pulls in her arms. This effect is known as conservation of angular momentum.