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Gravity
One of the four fundamental interactions, gravity is responsible for the fact that any objects with mass attract one another. According to general relativity, it is a space time curvature, but according to quantum mechanics it is the result of exchanges of virtual gravitons.
4,784 Questions
Does the Sun's gravity pull or push?
Straight Answer:
The force of gravity is attractive. It is only attractive.
It has been a matter of deep wonderment by some of the worlds' greatest scientists as to why one only sees gravity as an attractive force.
Complex Answer:
The above answer really responds to Newton's form of gravity. The answer is 100% correct, even if one interprets gravity in the sense of General Relativity.
However, if one is willing to entertain various complex and possibly unlikely scenarios, one can come up with different versions of gravity. Not all of these can be correct and maybe none are.
1. Half a century ago, antimatter was discovered. For example, a positron is an "anti-electron," identical to a positive electron and would attract a negative electron. Some people wondered if antimatter would also have the opposite of the normal gravitational force and repel normal mater.
2. After the first Voyager satellites were launched and went outside of the solar system, it was noticed that they were not leaving as fast as expected. After years of research trying to understand why they were going slower than expected, it was conjectured that Newtons law of gravity, might not be exactly correct for long distances, i.e. for distances of billions of kilometers. They just could not come up with any other explanation.
3. When Einstein first published his theory of General Relativity, the field equations had a term in them which was called the Cosmological Constant. In the first decades of the 20th century it was thought we lived in a static universe and something had to be present in the law of gravity to keep all the stars from falling in to one giant clump. That thing was the Cosmological Constant. Later, once it was established that we live in an expanding universe, Einstein characterized the first version of the theory, with the Cosmological Constant, as "the biggest mistake of my life."
4. A century after Einstein's biggest mistake, it has been discovered that the universe is accelerating, no just moving apart. Current theories now put the Cosmological Constant back into General Relativity to explain the acceleration.
5. Dark energy is the biggest unsolved mystery in science and has a tremendous implication on what is the correct law of gravity, the future of the universe and all manner of other fundamental questions.
Still, in all of the above, except antimatter, gravity was still attractive.
Where can you watch free episodes of gravity falls?
I usually watch Gravity Falls on watch cartoons online. You can't go on it directly, instead you have to search it on Google and click the first link you see. The page has many tones of orange, red and yellow. I hope this helps! ^-^
Why is the force of gravity on Pluto from the Sun the weakest?
-- Among the bodies that used to be the 9 planets, Pluto is the one
with the smallest mass.
-- Plus it's the one farthest from the sun.
These two parameters ... product of the masses involved and distance between them ...
are exactly the two factors that determine the forces of gravity between two objects.
In 2006, a planet became defined as a body orbiting the Sun that has a mass of self gravity sufficient enough to make it nearly round, and has a clear orbit.
A+ planet
How fast is a ball dropped 3 m going?
The answer will depend on whether you want the average speed during the 3 metre drop or the instantaneous speed when it has fallen 3 m.
Does gravity pull the sun towards earth?
Yes. The Earth and then Sun pull each other towards each other.
What is an object's acceleration due to gravity on earth?
That varies a bit from place to place, but it's around 9.8 meters/second2.
How can rockets overcome the earth's gravity?
Exactly the way you do it when you walk up stairs ... use your engines to
create a force greater than your weight and opposite to the force of gravity.
What is the surface gravity on the moon in newtons?
'Newton' is a unit of force. You can't measure gravity in units of force,
because we have all noticed that fat people weigh more than thin ones
even when they are all on the same planet.
-- The surface gravity on Earth is 9.81 newtons per kilogram of mass.
-- The surface gravity on the moon is 1.62 newtons per kilogram of mass.
(1 newton per kilogram of mass) is the same thing as (1 meter per second2).
That's an acceleration, which is the kind of unit to describe gravity with.
How does the space station overcome gravity?
Answer #1 .
Rockets were used to put the space station (and its various component parts) into orbit,
thereby overcoming gravity. Once in orbit, gravity continues to be overcome by the
angular momentum of the orbiting station. Sometimes it is necessary to use rockets
again, to add a bit more momentum, since there is still some friction even at that altitude.
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Answer #2 .
The parts of the space station certainly needed powerful rocket boosters to raise them
above the atmosphere, and accelerate them to a high enough tangential ('sideways')
speed to maintain orbit. But once that job is done, it doesn't take any more work to
stay in orbit. I mean, look at the Moon !
And actually, for that matter, you would not want the space station to overcome gravity,
because gravity is what keeps things in orbits.
What is the importance of doing specific gravity of urine?
s.g. is the density of a substance as compared to that of the density of water which is 1.000.s.g. of a solution depends on the amount of solute present and also on the temp. of the solution.the s.g. increases with increasing conc. of the solute.
the s.g. of normal urine is 1.003 to 1.030.if the kidney is functioning properly, the concentrated first morning sample of urine should have a s.g.greater than a.020.
usually, increased discharge of urine accompanied by decrease s.g.is typical of diabetes insipidus. on the other hand, high volume of urine discharged with increased s.g. suggests glucosuriya, associated with diabetes mellitus, or proteinuria.
if the conc. power of the kidney is disturbed, there is a combination of low s.g. and low volume of urine discharged. this occurs in case of glomerulonephritis and pyelonephritis.
two methods are employed in measuring the s.g., urinometer method and refractometer method.
What is the surface gravity of the planet Ceres compared to earth?
One of the largest asteroids, Ceres was discovered in 1801.
With its estimated average radius of about 461 km, and its estimated mass
of 9.43 x 1020 kg (0.00015 of Earth's mass, 0.0128 of the Moon's mass), the
acceleration of gravity on its surface is estimated at 0.27 m/s2, or 2.8% of
its value on the Earth's surface.
If you weigh 150 pounds on Earth, you'll weigh about 4pounds 2.1ounces on Ceres.
Who was the first person to write about gravity?
The scientist who wrote about gravity and the laws of motion was Sir Isaac Newton.
What does gravity Change on the body when you leave Earth?
Because gravity is the force of attraction between two objects, and the strength
of the force depends on the distance between them.
If the Earth is one of the objects and the other one leaves the Earth, then the force
of gravity it feels is certainly going to change.
Yes. Stars form when clouds of gas and dust, called nebulae, collapse under the force of gravity.
What will happen if gravity didin't exist?
If gravity did NOT exist, then we all would be floating in mid air and would float into things, like airplanes. Plus, then if we fall, we would be in outerspace. COOL!
What is relationship between Acceleration vs sin theta?
Any random individual might have some prayer of answering that question if he knew
what angle theta is. Without that information, the best anyone can do is guess, and
if he's smart, he won't even try to do that much.
Which country has more gravity?
Gravity is quite constant everywhere on Earth. Slightly more at lower elevations,
slightly less at higher ones, but never enough so that you would notice the difference.
There's no country on Earth that has generally more or less gravity than others have.
Why a person sitting on a chair in satellite feels weightless?
Since the "normal force" is zero.
(An example of a "normal force" is the upward force exerted by something as a reaction to the weight of an object which is on it.)
A fuller answer:
It's a bit like being in a fast moving elevator (a "lift"), but more extreme. When the elevator goes down, you feel a bit lighter.
Gravity is pulling you down just the same, but it's not pulling you into the falling elevator floor quite so hard.
On a space station you are in "free fall".
You and the spacecraft and everything in it are "falling" at the same rate.
The chair would not push up on you.
That makes you feel "weightless".
(Of course you don't fall to Earth because you also have a "forward velocity"
too and that keeps you in orbit.)
We sense gravity mainly by the fact that chairs, floors, etc resist the down force of our weight and push upwards on us.
(Actually the Earth's gravity is a bit weaker in space. In the International Space station it's about 90% of the Earth's surface gravity. But that's not the
reason you feel weightless.)
