In fluid mechanics, hydrostatic equilibrium (hydrostatic balance, hydrostasy) is the
condition of a fluid or plastic solid at rest
, which occurs when external forces, such as gravity, are balanced by a pressure-gradient force.
What is the hydrostatic condition?
hydrostatic condition:
when a fluid velocity is zero, the pressure variation is due only to the weight of the fluid
. • There is no pressure change in the horizontal direction. • There is a pressure change in the vertical direction proportional to the density, gravity, and depth change.
What is the principle of hydrostatic equilibrium?
The principle of hydrostatic equilibrium is that
the pressure at any point in a fluid at rest (whence, “hydrostatic”) is just due to the weight of the overlying fluid
.
What is hydrostatic equilibrium in atmosphere?
In climate: Characteristics. The atmosphere is mainly in hydrostatic balance, or equilibrium,
between the upward-directed pressure gradient force and the downward-directed force of gravity
.
What is hydrostatic equilibrium in a star quizlet?
A star is in hydrostatic equilibrium
when the outward push of pressure due to core burning is exactly in balance with the inward pull of gravity
. When the hydrogen in a star’s core has been used up, burning ceases, and gravity and pressure are no longer in balance. This causes the star to undergo significant changes.
Does Mercury have hydrostatic equilibrium?
Mercury is round but not actually in hydrostatic equilibrium
, but it is universally regarded as a planet nonetheless.
Is the sun in hydrostatic equilibrium?
It is made entirely of hot gas. Apart from some very tiny changes, the
Sun is neither expanding nor contracting
(it is in hydrostatic equilibrium) and puts out energy at a constant rate.
Why is it called hydrostatic equilibrium?
Hydrostatic equilibrium:
gravity compression is balanced by pressure outward
. … In any given layer of a star, there is a balance between the thermal pressure (outward) and the weight of the material above pressing downward (inward). This balance is called hydrostatic equilibrium. A star is like a balloon.
What are the two forces involved in hydrostatic equilibrium?
Hydrostatic equilibrium occurs when
compression due to gravity is balanced by a pressure gradient force in the opposite direction
. The balance of these two forces is known as the hydrostatic balance.
Are all stars in hydrostatic equilibrium?
For the majority of the life of a star, the gravitational force (due to the mass of the star) and the gas pressure (due to energy generation in the core of the star) balance, and the star is said to be in ‘hydrostatic equilibrium’.
Is a red giant in hydrostatic equilibrium?
These elements are all uniformly mixed throughout the star. The star reaches the main sequence when the core reaches a temperature high enough to begin fusing hydrogen (a few million kelvin) and establishes hydrostatic equilibrium.
Which of the following best describes hydrostatic equilibrium?
Hydrostatic equilibrium, also known as gravitational equilibrium, describes
a balance between gravity and pressure
. Gravity works to contract while pressure works to expand.
What does it mean if a star is in hydrostatic equilibrium?
A star is “in hydrostatic equilibrium” when it is not collapsing or expanding. Page 7.
Inside a star the weight of the matter is supported by a gradient in the pressure
. If the pressure on the top and bottom of a layer were exactly the same, the layer would fall because of its weight.
Is Miranda in hydrostatic equilibrium?
At just 470 km in diameter, Miranda is one of the smallest closely observed objects in the Solar System that might be in
hydrostatic equilibrium
(spherical under its own gravity).
What planet is Uranus?
Uranus is
the seventh planet from the Sun
, and has the third-largest diameter in our solar system. It was the first planet found with the aid of a telescope, Uranus was discovered in 1781 by astronomer William Herschel, although he originally thought it was either a comet or a star.
Is the moon in hydrostatic equilibrium?
The smallest body confirmed to be in hydrostatic equilibrium is the dwarf planet Ceres, which is icy, at 945 km, whereas the largest body known to not be in hydrostatic equilibrium is the Moon,
which
is rocky, at 3,474 km.
What is gravitational equilibrium?
Gravitational equilibrium.
A state of balance in which the force of gravity pulling inward is precisely counteracted by pressure pushing outward
.
Energy balance
. The balance between the rate at which fusion releases energy in the star’s core and the rate at which the star’s surface radiates this energy into space.
What is the largest star in the universe?
The largest known star in the universe is
UY Scuti
, a hypergiant with a radius around 1,700 times larger than the sun. And it’s not alone in dwarfing Earth’s dominant star.
What forces keep the Sun in equilibrium?
However, the Sun is a giant ball of gas, and the pressure to stop collapse must come from within the Sun. In fact, it is
thermal and radiation pressures
which create an outward expansion force which balances the inward contraction due to the force of gravity. This balance is called hydrostatic equilibrium.
Will the Sun turn into a black hole?
Will the Sun become a black hole? No, it’s too small for that!
The Sun would need to be about 20 times more massive to end its life as a black hole
. … In some 6 billion years it will end up as a white dwarf — a small, dense remnant of a star that glows from leftover heat.
What type of star is our sun?
The Sun is a 4.5 billion-year-old
yellow dwarf star
– a hot glowing ball of hydrogen and helium – at the center of our solar system.
What stages are stars in hydrostatic equilibrium?
During
the Main Sequence phase
, core hydrogen fusion creates the pressure (in the form of radiation pressure and thermal pressure) that maintains hydrostatic equilibrium in a star, so you should expect that when a star’s core has become filled with helium and inert, the star will fall out of equilibrium.
Is Arcturus red?
Arcturus is a
red giant star
in the Northern Hemisphere of Earth’s sky and the brightest star in the constellation Boötes (the herdsman). Arcturus is also among the brightest stars that can be seen from Earth.
Do brown dwarfs have fusion?
Brown dwarfs are an odd set of objects that are neither planets nor stars. … However, if a brown dwarf has at least 13 times the mass of Jupiter, it can ignite a limited form of fusion. These brown dwarfs
fuse a heavy isotope of hydrogen
, called deuterium, into helium, releasing energy like a star.
Why Sun will become a red giant?
A: Roughly 5 billion years from now,
the Sun will exhaust the hydrogen fuel in its core and start burning helium, forcing its transition
into a red giant star. During this shift, its atmosphere will expand out to somewhere around 1 astronomical unit — the current average Earth-Sun distance.
