What is Gravitational attraction: Definition and 68 Discussions
Gravity (from Latin gravitas 'weight'), or gravitation, is a natural phenomenon by which all things with mass or energy—including planets, stars, galaxies, and even light—are attracted to (or gravitate toward) one another. On Earth, gravity gives weight to physical objects, and the Moon's gravity causes the ocean tides. The gravitational attraction of the original gaseous matter present in the Universe caused it to begin coalescing and forming stars and caused the stars to group together into galaxies, so gravity is responsible for many of the large-scale structures in the Universe. Gravity has an infinite range, although its effects become weaker as objects get further away.
Gravity is most accurately described by the general theory of relativity (proposed by Albert Einstein in 1915), which describes gravity not as a force, but as a consequence of masses moving along geodesic lines in a curved spacetime caused by the uneven distribution of mass. The most extreme example of this curvature of spacetime is a black hole, from which nothing—not even light—can escape once past the black hole's event horizon. However, for most applications, gravity is well approximated by Newton's law of universal gravitation, which describes gravity as a force causing any two bodies to be attracted toward each other, with magnitude proportional to the product of their masses and inversely proportional to the square of the distance between them.
Gravity is the weakest of the four fundamental interactions of physics, approximately 1038 times weaker than the strong interaction, 1036 times weaker than the electromagnetic force and 1029 times weaker than the weak interaction. As a consequence, it has no significant influence at the level of subatomic particles. In contrast, it is the dominant interaction at the macroscopic scale, and is the cause of the formation, shape and trajectory (orbit) of astronomical bodies.
Current models of particle physics imply that the earliest instance of gravity in the Universe, possibly in the form of quantum gravity, supergravity or a gravitational singularity, along with ordinary space and time, developed during the Planck epoch (up to 10−43 seconds after the birth of the Universe), possibly from a primeval state, such as a false vacuum, quantum vacuum or virtual particle, in a currently unknown manner. Attempts to develop a theory of gravity consistent with quantum mechanics, a quantum gravity theory, which would allow gravity to be united in a common mathematical framework (a theory of everything) with the other three fundamental interactions of physics, are a current area of research.
When one mass is held fixed, the other mass acquires a speed v from gravity.
I don't understand the following explanation:
When both masses can move, they share the kinetic energy, so both have speed v/√2, so the relative speed is √2v. Hence to collapse the same distance r, the latter case will...
Hi! Isn't gravity just a smaller object moving toward the lower energy state created by a larger object (time slows down the closer you are to a massive object)? Why do we need a force carrying particle for gravity?
I am thinking of the mechanism that causes mass-energy to curve spacetime
We have the Wheeler (was it ?)description, viz approx "mass tells spacetime how to curve and spacetime tells matter how to move...".
Are there any analogous circumstances in other areas of physics where all (or a...
When people try to explain how gravity works, the following example is constantly used .
However, I don’t understand how this explains HOW gravity works. By using this example, gravity itself is used as a bias to explain how gravity works. How can explain gravity by saying “things fall along...
The thing is, I've already looked up at the solution online at it's t= 2a/3v. But I've approached it a different way and I can't really tell what I'm doing wrong, my solutions gives out t= (a/√3v )* (π/3),I don't know what's wrong with it. Here's my approach:
The points will meet at the...
<< Mentor Note -- thread moved from the Introductions forum to the technical forums >>
Hello there,
This is my first post, I find myself often wondering about the universe and how it works, and there are a couple of things I just can't wrap my head around.
According to wikipedia the force that...
Imagine a ball being tossed into 'the air'. At its peak, the ball has a velocity of 0(m/s), but how long does it actually have this velocity for? --> Neglecting the effects of air-resistance.
Obviously the ball undergoes constant 'g' the whole time, but the answer to my question doesn't relate...
Hi.
If 2 equal masses are placed at rest ( an arbitrary distance apart ) on a horizontal friction-less surface do they accelerate from rest towards each other until they collide ?
Thanks
Homework Statement
Distance Earth-Sun at perihelion = 1.471×108 km
Distance Earth-Sun at aphelion = 1.521×108 km
Sun mass = 2.0×1030 kg
Earth mass = 5.972×1024 kg
G = 6.67×10-11 m3/kg⋅s
What is the change in Newton of the attraction force between the Sun and the Earth from the perihelion to the...
Hello! I am implementing the three body restricted problem numerically (2 of them are massive and the 3rd one is not affecting them, so it is just moving in the potential created by them). I implemented it and if I put the 3rd one close to one of the big ones it moves in circles around it, while...
say i were standing next to something very massive, like a battleship in drydock, and i were to hold a feather (not massive) very close to it. Would i witness any gravitational attraction between the feather and the ship? If not, why not? What if i did the same with a single filament of spider...
hi
I'm writing a javascript application to illustrate gravitational attraction between masses, but am getting hung up on some of the details, particularly mow far masses move in response to each other's gravitation.
I've read all available wikipedia articles on gravity and have come up with...
Homework Statement
By what angle, in seconds of arc, will a plumbline be pulled out of its normal vertical direction by the gravitation attraction of a 10-ton that parks 20 ft away? Do you think that this effect could be detected?
Homework Equations
I think (G*m1*m2)/r^2
The Attempt at a...
The question: Is there a gravitational attraction between two atoms if they are located at a distance of several light years of each other? Or physics does not have the answer to this question yet? )
(Sorry if this question has already been discussed on the forum. Please send a link to the topic...
I didn't study physics in college nor any other science major, but I love physics and read a lot about it. Still I find troubling contradictions in my understanding of Newton's interpretation of gravity.
For starters, how can the force of gravity be directly proportional to the two masses? If...
Homework Statement
Two solid copper spheres of radii 1 and 2 cm are released from rest in free space, their centers being 20 cm apart. Estimate the velocity with which they collide
Homework Equations
density =mass/volume
F=GMm/r^2
The Attempt at a Solution
Find mass of each from density of...
Hi all. New to physics forum and glad to be here.
I have been referencing the site for a while now and have finally come up with a question i haven't been able to find on here. So I guess i thank all of you who are already on here for the help.
Assumptions:
-Imagine an infinitely...
So the formula is F=Gm1m2/r^2. Could you substitute one of the mass values for an energy value since gravity attracts energy ? Or would this require a different equation?
Hi, the following two views appear inconsistent to me:
In the infinite perfectly homogeneous universe:
a) the net force of gravity is zero everywhere, so no energy is being exchanged and no particle is pulled in any direction whatsoever.
b) the net force of gravity within a spherical...
Homework Statement
The gravitational attraction due to a nearby mountain range might be expected to cause a plumb
bob to hang at an angle slightly different from the vertical. If a mountain range could be
represented by an infinite half-cylinder of radius a and density ρ lying on a flat plane...
Since we can observe gravitational lensing and conclude that mass can affect the path of EM radiation it seems logical to me to assume that EM radiation will exert a slight gravitational attraction of it's own on a mass,- although I do not recall ever reading about this.
Presumably the...
Hello, comparing the formula of gravitational attraction with F = m*a you get that the smaller mass disappear.
I don't think this is physically correct, do you ?
thank you
Homework Statement
two point masses (400 kg) are 10^14 m apart in deep space under no gravitational attraction besides each others. find their velocity when they are 1000 m apart.Homework Equations
-G (m_1m_2)/r^2=F
The Attempt at a Solution
I integrated the equation above plugging in the 400...
Find the gravitational attraction of a solid hemisphere of radius a anddensity1 on a unit point mass placed at its pole.
My attempt:
Obviously I figured that spherical coordinates would work nicely for this problem.
I decided to invert the hemisphere thus placing the pole on the origin...
I would like to better understand the nature of gravitational attraction and the law of conservation of energy.
Imagine you measure inertial mass (using inertial ballance) of an object far from a gravitating mass which is at rest relative to the object. Then you release the object and let it...
Homework Statement
i need to find the work of gravitational attraction based on heights of balls being shot into the air. the mass of the ball is 24 grams, the height is 27cm at 0 degrees, 38 at 30 degrees, 50 at 45 degrees, 61 at 60 degrees, 80 at 90 degrees.
i also need to find the initial...
I was wondering about a scenario where we have a unit mass M1 and a thin rod of mass M2 of length L with a distance r between them attracting each other . Is my following approach to the problem correct ??!
let s = r + L
I know that F= -(GM1M2)/(s^2) where G is gravitation constant
therefore...
Each mass in the figure below is 2.00. Find the magnitude of the net gravitational force on mass A due to the other masses in figure b (the square).
Figure: http://i.imgur.com/fjSgU.jpg
attempt:
i used the formula F=G [(m1*m2)/r^2]. all of the forces are in the direction of D so i...
The book says..bodies experience mutual gravitational
attraction with each particle of the earth...
In the picture... the vector from the apple pointing to the center of the earth.. is that the attractive force of by the Earth attracting the apple?
and what about the vector pointing from...
Homework Statement
Two asteroids of 1.0x107kg and 6.0x107kg respectively, are initially at rest in interstellar space separated by a large distance. Thier mutual gravitational attraction then causes then to fall toward each other on a straight line. Assume the asteroids are spheres of radius...
Hello everyone,
I have been stuck on this geophysics question I have for one of my classes and I really need some help with it. Can anyone solve this question. If you do, please show me how because I am really stuck here. I am stuck on both a and b. Click the link below to see the question...
Many sources on basic gravity, like this quote from Wikipedia, say:
“In the case of a spherically symmetric mass distribution we can conclude (by using a spherical Gaussian surface) that the field strength at a distance r from the center is inward with a magnitude of G/ r^2 times only the...
I was wondering what equations govern calculating the gravitation attraction of a massive particle (say a proton) traveling at near light speed? Thanks!
We can imagine a sphere floating freely in space. Perhaps it is something like a ping pong ball. We attach a piece of string to a random position on the surface of the sphere. If we vibrate the string, the sphere will be pulled in the direction of the string. If we repeatedly move the...
Homework Statement
what is the gravitational attraction between two students with masses of 70 kg and 50 kg, if they are 1.5 m apart?
Homework Equations
Fg=Gm1m2/r^2
The Attempt at a Solution
so my Fg is 6.67 x 10^-11, m1 is 70 kg and m2 is 50 kg. for my radius, do i just use the 1.5...
Is there a distance where the curvature in spacetime created by an object's mass ends? Is it a finite gravity well or does the curvature just get infinitely weaker?
Could the effect of "Dark Matter" be explained if in the formaul for Gravitational attraction:
F = GMm/d^x
Where x is considered 2 is wee bit less (may be 1.98 or some thing)
Suppose that in free space , dust particles are evenly distributed all around.
Amidst the dust particles , there are two identical spherical cavities at some distance from each other. Do you think they will attract each other or repel or just be as they were??
Trying to figure out the gravitational attraction between two objects using Newton's Law of Universal Gravity.Need to figure out what the force is.Here is a model.If anything is in ordinary parentheses then it is an exponent.
----------------------G
--------____________|_____________400x300...
[b]1. The mass of the Moon is 7.35x10^22 kg. At some point between Earth and the Moon, the force of Earth's gravitational attraction on an object is canceled by the Moon's force of gravitational attraction. If the distance between Earth and the Moon (centre to centre) is 3.84x10^5 km, calculate...
Homework Statement
The mass of the Moon is 7.36 x 10 ^ 22 kg. At some point between Earth and the Moon, the force of Earth's gravitational attraction on an object is canceled by the Moon's force of gravitational attraction. If the distance between Earth and the Moon (center to center) is 3.84...
2 particles are moving very fast in an "inertial reference frame." What is the force of gravitational attraction between them?
Note that at low speeds it is G(m1)(m2)/r^2. Also note that the two particles are not aware of the inertial reference frame with respect to which they are moving very...
I'm just curious how long it would take for two 1kg masses separated by 1m to attract each other gravitationally in empty space. The formula for gravitational force is:
F_{g} = G \frac{m_{1}m_{2}}{r^{2}}
where r is the distance between the two masses.
So if the midpoint for the two...
Homework Statement
A small mass M and a small mass 3M are 3.60m apart. Where should you put a third small mass so that the net gravitational force on it due to the other two masses is zero?(From mass M)
Homework Equations
F = G(m1)(m2)/d^2
The Attempt at a Solution
I envisioned...
Homework Statement
The mass of the Moon is 7.35x10^22 kg. At some point between Earth and the Moon, the force of Earth's gravitational attraction on an object is canceled by the Moon's force of gravitational attraction. If the distance between Earth and the Mon (centre to centre) is 3.84x10^5...
The mass of the moon is 7.35*10^22Kg. At some point between Earth and the moon, the force of Earth's gravitational attraction on an object is canceled by the moon's force of gravitational attraction. If the distance between Earth and the moon (centre to centre) is 3.84*10^5 Km, calculate where...
Homework Statement
The mass of the moon is 7.35x10^22 kg. At some point between Earth and the Moon, the force of Earth's gravitational attraction on an object is canceled by the Moon's force of gravitational attraction. If the distance between Earth and the Moon (centre to centre) is...
Gravitational Attraction-Please Help!
Homework Statement
Two 100kg lead sphers are suspended from 100m long massless cables. The tops of the cables have been anchored 1 m apart. What is the distance between the center of the spheres?
Homework Equations
Fg= Gm1m2/r^2
The Attempt at...