I ve been confused about gravitational versus gravity in space, can anyone explain it clearly

Gravitational force must exist, and gravity is actually a component force, because the centripetal force required to stay on the surface of the earth is very small, so gravity and gravity can be regarded as equal, and the weightlessness of flying around the earth is centripetal force equal to gravity, and outer space flight is microgravity, and it will be subject to some other forces, but it is very small.

Quantitative analysis of complete weightlessness:

When a g, the supporting force is n, which is known by Newton's second law:

mg－n＝ma＝mg

So n 0 is known from Newton's third law, and the pressure of an object on a support is 0 with respect to the concept of microgravity.

Complete weightlessness is an ideal situation, and in actual space flight, the spacecraft will be subjected to some non-gravitational external forces from time to time in addition to gravity. For example, there is the resistance of the residual atmosphere near the Earth, the pressure of the sun's rays, and the force of the atmosphere on it when entering a planet with an atmosphere. According to Newton's second law, the result of the action of force on an object is to cause the object to gain acceleration.

When a spacecraft flies in a gravitational field, the non-gravitational force experienced is generally very small, and the acceleration produced is also small. This non-gravitational acceleration is usually only 1/10,000th or less of the acceleration of gravity on the ground. In contrast to normal gravity, this phenomenon of microacceleration is called "microgravity".

In fact, even if a spacecraft is only subjected to gravity, there is actually microgravity inside it, and this is because the spacecraft is not a particle, but an object of a certain size.

There is almost no gravity in weightlessness in space, and the gravitational force can be based on the square of f=gmm r, with m, m, r.

The square is directly proportional to m, m and inversely proportional to the square of r

Hope you are more in physics than the class chaomans

Because there is gravity, gravity is constant, and it should be said that a fixed value is taken because the difference is too close, but it is actually constantly changing, which is the problem of gravitation.

The gravitational pull of the earth on people is the gravitational force of people, this is the definition, what is there to mix? Be specific.

Because the earth is under the action of the atmosphere, the whole planet has the effect of gravitational pressure and friction, so it is clear from space, and the space exploration of astronauts from various countries is the basis.

The earth is just a tiny planet like a speck of dust in the vast universe, and the solar system in which it is located is only one of the many galaxies in the Milky Way, and not every of the eight planets in the solar system has an environment suitable for human survival and a comfortable climate like the earth.

The force works vertically downward, and the Earth, under the protection of the outer atmosphere, has gravitational pressure and friction on the inner ground of the planet, which allows us to walk and work normally for a day, while space is not, and it is impossible to survive in an almost vacuum environment.

The magnitude and direction of gravity

The force exerted on an object due to the attraction of the earth is called gravity. The direction is always straight downwards and is not necessarily directed towards the center of the earth (only at the equator and the poles point to the center of the earth). The gravitational force of the object at the same point on the ground is proportional to the mass m of the object, and similarly, when m is constant, the gravitational force of the object is proportional to the acceleration of gravity g, which is expressed by the relation g=mg.

Usually near the earth's surface, the g value is about, which means that the gravitational force experienced by an object with a mass of 1kg is.

The above content reference: Encyclopedia - Gravity.

The question is the problem, why despise the subject. Who hasn't come from a head full of questions!

1.First of all, what is gravity.

Gravity is another expression of the Earth's gravitational pull on objects. So, as long as we consider where the earth has gravity, we can say that there is gravity.

2.Is there gravity in space?

The gravitational force decays with the square of the distance, so it is said that the gravitational force on the object decays with the square of the distance from the object to the earth. Therefore, whether there is gravity or not should be determined by distance. For example, near the earth, the moon, and various artificial satellites, their positions are definitely subject to gravity, and the space far away from the solar system absolutely does not need to consider gravity, why, because the earth's gravitational pull on it is infinitely close to 0.

3.What is the state of complete weightlessness (zero gravity) of the space station crew.

First of all, why do we feel that we are subjected to gravity, because the ground gives us support, and both the support force and gravity act on us, so we keep the ground relatively still. Note that the support force and gravity are not the same force, and the space station is also subject to gravity, which has been answered in Part 2, but because the space station and we both smashed to the earth's surface at the same time, the space station will not give us support force, which is what we often call complete weightlessness, so zero gravity is accurately expressed as zero support force.

4.Why does the space station fall to the Earth's surface despite gravity?

First of all, the space station is smashing into the surface of the earth all the time, and at the same time, you must know that it is moving horizontally all the time, the earth is round, if it keeps it horizontal, it will be far away from the earth, right, so it will fall down, but how much, it will fall to a circular or elliptical orbit. This is a diagram to help you understand.

5.Finally, I hope that the subject will remain curious about the world, knowledge can be learned, but curiosity cannot be learned!

Why is there no gravity in space, and still meteors fall?

There is gravity in space.

In space, gravity acts as the centripetal force (partially) of an object moving in a circular motion around the Earth

The force that arises due to the attraction of the earth is called gravity. Direction: Straight down. The gravitational force of an object g is proportional to the mass m of the object and is expressed by the relation g=mg.

Usually near the earth's surface, g is taken as a cow per kilogram, indicating that the gravitational force on an object with a mass of 1 kilogram is a cow.

All parts of the object are subject to gravity. However, from the point of view of the effect, we can think that the gravitational action of each part is concentrated in one point, and this point is the point of gravity, which is called the center of gravity of the object. The position of the center of gravity is related to the geometry and mass distribution of the object.

Gravity is not equal to the gravitational pull of the Earth on an object. Due to the rotation of the earth itself, in addition to the poles, objects in other places on the ground are moving in a uniform circle around the earth's axis with the earth, which requires a centripetal force pointing perpendicular to the earth's axis, and this centripetal force can only be provided by the earth's gravitational force on the object, we can decompose the earth's gravitational force on the object into two components, one component f1, the direction points to the earth's axis, and the magnitude is equal to the centripetal force required for the object to move in a uniform circular motion around the earth's axis; The other component g is the gravitational force on the object (illustrated), where f1 = mw2r (w is the angular velocity of the earth's rotation and r is the radius of rotation of the object), which shows that the magnitude of f1 is zero at the poles, increasing with the decrease of latitude, and the maximum f1max is in the equatorial region. Because the centripetal force of the object is very small, in general, it can be considered that the gravitational force of the object is the magnitude of the gravitational force, that is, the effect of the rotation of the earth can be omitted in general.

where the gravitational component of gravity provides gravitational acceleration and the centripetal component of gravity provides centripetal acceleration that maintains rotation with the earth.

The magnitude of gravity can be measured with a dynamometer, and the amount of tension or pressure of an object on the dynamometer is the magnitude of gravity.

<> there is gravity in space. On Earth, the gravitational force generated by the mass of an object, acting on an object in contact with the ground, is what we call weight. Objects orbiting in space still have mass, which creates their own gravitational region.

All stars with massive masses in space, like the Sun, Earth, and other planets, are gravitational. The weightlessness of an object moving in space is not due to the absence of gravity, but the disappearance of gravity. Once there is resistance, such as atmospheric resistance, engine power, centrifugal acceleration due to rotation, etc., the phenomenon of weightlessness is gone.

The reason why there is no gravity in space is because the definition of gravity is established near the ground of the planet, and it cannot be applied to space farther from the ground, let alone cosmic space, so it is said that there is no gravity in space.

Gravity is the only physical quantity among all physical quantities that can have many versions at the same time, which is not an ordinary phenomenon. This shows that there are considerable difficulties in establishing a definition of gravity. Physical quantities in mechanics such as gravitation, elasticity, and friction, as well as the definitions of various physical quantities in thermal, optical, electrical, and atomic physics, have all established a single precise version.

There is no single version of the definition of gravity that excludes the existence of other versions and excludes its place in mechanics. The difficulty of establishing a definition of gravity has forced the discussion of gravity to be shunned. This phenomenon, which is more difficult to understand than advanced science, does not conform to the laws of man's understanding of the natural world.

It's not because of the loss of gravity, gravity is everywhere, it's just that the farther away you are, the smaller the gravitational pull, and weightlessness is just an "illusion". Gravitational forces make you do other motions instead of falling, and space is weightless because of leaving the gravitational pull of the Earth. If you look at the formula for calculating gravitational force, you will naturally know (if the distance is too large, the gravitational force will be small).

There is no gravitational pull. So it will be weightless. There is basically no gravitational field outside the earth's atmosphere, so people can't feel gravity in space, but the total moving of the universe is just not felt! Without gravity, weightless?

The definition of weightlessness is a phenomenon in which the pressure of an object on a support is less than the gravitational force experienced by the object. If you think about it carefully, you will find that this definition sets a premise for the phenomenon of weightlessness, that is, the existence of a gravitational field. Without a gravitational field, there is no gravity, and there is no weightlessness.

In other words, according to this definition, weightlessness occurs only within the gravitational pull of celestial bodies.

For space without a gravitational field (which is negligible or equilibrium with centrifugal acceleration, it is all included in the absence of a gravitational field), there is no weightlessness according to the above definition due to the absence of gravity. The state of gravity in space, on the other hand, is also customarily called weightlessness because it feels similar to weightlessness.

The state of "weightlessness" in space is a state of detachment from the force field, or the state of complete absence of gravity. This is known from the situation of the astronaut levitating on the spacecraft.

Weightlessness is not the loss of gravity, but people in space have to make a circular motion around the earth, and the circular motion requires a centripetal force, and this centripetal force is provided by the gravitational force (gravity) of the earth on people. In other words, the gravitational force exerted on man in space is used to maintain man's circular motion around the earth.

In fact, when the spacecraft flies in space, it will still be affected by some and its thin atmosphere, so it is only doing an approximate flat throwing motion (which is the superposition of approximate uniform linear motion and approximate free fall), so the spacecraft is not completely weightless, but in a state of microgravity.

Gravity is the force experienced by objects that rotate with the earth, generally near the earth's surface. Gravity is equal to one component of the gravitational force, and the other component is the centripetal force of the object as it rotates with the earth.

There are also two types of objects in space, one is objects that revolve around the earth, such as satellites. Although the satellite revolves around the earth, it does not rotate with the earth, so the gravitational force completely provides the centripetal force, that is to say, the component of gravity is zero, and it can be said that the satellite, including the people in the spaceship in the tumble, are not affected by gravity.

In addition, objects in space that do not revolve around the earth, such as other planets, passing meteorites, etc., must be affected by the gravitational force of the earth, but there is no centripetal force at all, let alone gravity.

Until now, all the ideas of creating artificial gravity in space have remained on paper, or science fiction.

Middle! But in fact, artificial gravity can be realized, and it may require certain structures and technologies, such as the following:

In space, it is feasible to create "artificial gravity" by rotating a spacecraft or space station. Centrifugal force when the space station rotates.

will pull the person outward, and this process can be used to simulate gravity. But it won't be exactly the same because of the greater Coriolis force.

A description of the offset of a particle in a rotating system that is moving in a linear motion relative to the linear motion produced by the rotating system due to inertia. The Coriolis force is derived from the inertia of the motion of an object. ) will also appear, so the trajectory will fall into a curve instead of a straight line.

The rotating cabin, which is the astronaut living module generated by artificial gravity, is not really gravity, but centrifugal force simulated gravity, which is the opposite of gravity centripetal, centrifugal force is the center of rotation radioactivity.

Outwardly! <>

The Martian. The same is true for the Helms, but its diameter is significantly smaller than that of the Star, so if you want to generate enough centrifugal force to simulate gravity, its relatively high rotational speed should be very uncomfortable! Because the speed of the human body under simulated gravity is 1-2 revolutions per minute, if it exceeds 3 revolutions, it will be dizzy.

The higher it is, the more dangerous it is!

Eternity also simulates gravity through centrifugal force, and contrary to Helms, it seems that the entire structure of Eternity is annular shaped, but please note that the cockpit in the middle is fixed, so it has a rotating structure to prevent the cockpit from turning!

In addition to centrifugal force, other ways of direct and violent acceleration are too far away from us, because with our current technology, we can only get out of the atmosphere.

Enjoy! Because the specific impulse of our engine is not enough, this acceleration is unsustainable, so hope is dashed!

Another example is like Star Trek.

The gravity formula of advanced technology is even more distant, and I don't even know how to implement it, let alone start simulating it!

Of course, we don't have to think too much, because we can't even realize the most basic centrifugal force simulation gravity (mainly because the structure is too large, and it is really difficult to bear with the current technical cost)! So on the ISS.

Don't think about it, it's almost retired, what's the toss?