If there is no gravitational spaceship would

When gravitational pull an object in a uniform circular motion, the gravitational force pulled is just equal to the centripetal force required.

When the gravitational pull is not enough, the object moves centrifugally. Because the centripetal force required for a farther orbit is smaller, the object will move in a uniform circular motion in a higher orbit when the physical gravitational force is just equal to the centripetal force in a farther orbit.

Without gravity, things would have gone viral.

First of all, the Earth may not be the Earth's Earth'If there is no gravity, the earth will not shrink into a sphere, and the ancient saying that the sky is round is possible in this case.

If the earth is still a sphere and there is no gravitational force, it is equivalent to weightlessness in a vacuum, which can be understood by referring to the appearance of astronauts in space.

Then you don't have to invent a spaceship, you can go to the moon with a kick and push the moon to the sun with a sneeze. The poop will not fall into the toilet, and it will probably fly to Mars as soon as it is pulled out!

If nothing else, let's talk about spaceships.

The spacecraft is moving in a circle, it has a linear velocity, and when the gravitational force (centripetal force) is lost, the spacecraft will go tangentially from a point in the circle with the linear velocity, and fly towards space in the direction of the resultant force generated by the centrifugal force.

Since time immemorial, when people look up at the stars, the sight of the sky has attracted their attention. The mind of the wise pole began to explore the mysteries of astral motion. In the 17th century, Newton succeeded in explaining and missing the laws of celestial motion by unifying the phenomena in the sky with those on the ground with his great work.

Today, thousands of artificial Earth satellites are orbiting the Earth in orbits "set" for them according to the law of gravitation.

Newton's discovery of the law of gravitation was so brilliant that when Apollo 8 returned to Earth from the moon, when the ground control center asked "who is driving", the commander said: "I think Newton is driving now." ”

We should understand the law of gravitation, which has a profound impact on mankind and plays a decisive role in the movement of celestial bodies, and its development history and role in human exploration of space.

It is a serious mistake to think that there is no gravitational force in space, gravitational force is a long-range force, and theoretically no matter how far away it is, there will still be gravity, so the speed of the spacecraft in space cannot be maintained all the time. Our universe was born 13.8 billion years ago, and if it weren't for the original big**, you and I would no longer exist today.

The spacecraft needs to be at a great speed to maintain Earth orbit and must reach the first cosmic velocity.

Then rely on gravitational potential energy.

and the conversion of kinetic energy, which runs in the Earth's orbit. When working normally, the spacecraft is not not affected by the earth's gravity, without gravity, the spacecraft's elliptical orbit cannot be maintained, and at the same time, because there is a very thin earth's atmosphere near the perigee, it is subject to weak air resistance, and because the gravity of the earth is not balanced, so many artificial satellites are many.

Or a spaceship.

If there is no one to maintain it in Earth orbit, the final result will be to fall to the Earth.

Because of the nature of gravity, no matter how far the spacecraft is, it will still have a gravitational effect, so the spacecraft must reach a certain speed in order to "fly all the way forward". reach the first cosmic velocity per kilometer and orbit the Earth; Reach the second cosmic velocity of kilometers per second.

It is possible to get rid of the gravitational pull of the Earth and enter the orbit of the sun, and reaching the third cosmic velocity of kilometers per second can get out of the solar system.

gravity, flying out of the solar system, but impossible to fly out of the Milky Way.

Because that would require reaching the fourth cosmic velocity.

These speeds are the minimum speeds that fly out of the area, in fact, due to the influence of gravity, the speed of the spacecraft will gradually decrease, and there is no such thing as the subject said that it will fly all the way if it is given a little power, and it will gradually slow down under the action of gravity, change its orbit, and finally stay in a certain star field or be captured by a celestial body. If we need to get rid of the gravitational pull of the Earth or even the gravitational pull of the Sun to send satellites to far outer space, then we need to do much faster. So now you know why satellite launches need to be very fast.

Yes. Because there is no gravitational force in space, all matter is weightless, and there is no friction in space, so the spacecraft can fly all the way forward.

I think it can fly without pushing it, because without gravity, there is no gravity, and then things have no support point at all.

Not necessarily, because space is a vacuum, so there is no air flow to guide the spacecraft to continue flying, and it may be suspended.

Of course, there is a gravitational effect. All the stars in the universe exert a gravitational pull on the spaceship. These gravitational forces are similar to centrifugal forces such as centrifugal forces generated by the spacecraft's own motion.

A class of forces work together on the spacecraft, and when the resultant force of these forces is balanced, weightlessness is generated.

The so-called gravity generally refers to the gravitational force of the earth experienced by the object, which is also the gravitational force.

When the spacecraft flies in orbit around the earth, it produces centrifugal force due to circular motion, and this centrifugal force is equal to the gravitational force of the earth acting on the spacecraft, and the direction is opposite, and the resultant force is zero, so weightlessness appears. If there is no attraction of the Earth to the spaceship, which is commonly known as gravity, the spacecraft will move away from the Earth due to the centrifugal force generated by the circular motion of the earth, which is usually called the centripetal force that maintains the circular motion of the object and counteracts the centrifugal force.

So in this example, "gravity" becomes "centripetal force".

The gravitational pull of the Earth is a gravitational force that is directly proportional to the product of the masses of both sides and inversely proportional to the square of the distance. Therefore, no matter how far the spacecraft flies, it will be attracted by the gravitational pull of the Earth.

The spacecraft does not fall because the centrifugal force in the spacecraft flying around the earth is exactly equal to the gravitational force of the earth. At this point, the faster the ship goes, it will leave the Earth, and if it slower, it will fall.

This relies on the law of gravitation.

The gravitational force between objects and objects.

1.（1）10%gm/r^2=(2π/t)^2r->ρm/(4/3πr^3)=(30π)/gt^2)2)(2π/t')^2r=10(2π/t)^2r->t'Hunger = 10t

2.Let the angular velocity of the Earth be 1 and the asteroid be 2

Earth orbit grinding outer side -->1> 2

So 2 (1- 2)=t --2=(2 )(1 t-1 t)m day = 4( 2)(r 3) (gt 2)=(2) 2*r2 3 g->r2=r(t 2 (t-t) 2)) 1 3) minimum distance: r2-r=r((t 2 (t-t) 2)) 1 3)-1) because if b is right, then d is also right, so neither is true.

Then we look at the centripetal force to increase and return to the large, and there must be a decrease in r and a greater velocity, so it is c

Correct option c. In terms A, both object A and satellite C are in circumferential orbits, with different heights, and according to the formula of gravitation, the gravitational force is different, and thus the acceleration is different. or a=f m gm r.

The B term f = mv r can be obtained that the linear velocity of object A and satellite C is different. Item c.

Because these two orbits are within the action of the earth's gravity, but the apogee of the orbit where B is located is farther than the orbit where C is located, that is, the orbital potential energy of B is higher than that of C, and at the same point P, B needs more acceleration to go farther, and the speed of the two is only related to their distance from the center of the earth, so at point P B, C linear velocity is equal. That should make sense, right?

The correct option is C, because the acceleration is only related to its own mass and the magnitude of the external force, and has nothing to do with the state of motion

Exclude phase A, and based on the analysis of the C term, it can be seen that phase A is wrong.

Exclude phase B, because object A has the same period as satellite C, then, in a period, satellite C has a larger radius and travels a larger distance than object A, so object A and satellite C have different velocities.

Excluding phase d, according to Kepler's second law, the line between a planet and a star sweeps the area in equal time, etc. Since it is not possible to determine the orbital area of satellite B and the orbital area of satellite C, it is not possible to determine the linear velocity of B and C at point P. The magnitude cannot be judged based on the direction of the satellite at the next moment, because at point p, the velocity direction of b and c is different.

Even if the velocity of b is small, as long as its velocity direction is away from the Earth and not perpendicular to the Earth, the trajectory is still elliptical. The conclusion is that satellite B has the same acceleration as satellite C at point p. To determine the linear velocity, you need to know its orbital area, and the planet with a large orbital area has a large linear velocity at point p.

You can look up the formula for celestial motion, which is compulsory in general high school physics textbooks. There are too many words, after all, high school students also have to study for a month or two. To put it simply, yes.

Because there is a gravitational force between the Earth and the moon (the law of gravitation: fr 2=gmm).

Therefore, the satellite is attracted every moment, as long as the velocity is appropriate, it will become a uniform circular motion (f=mv 2r) This is the law when the object is in circular motion, when the object A rotates around the point B, there needs to be a centripetal force f, otherwise it is impossible to maintain a uniform circular motion.

Of course, if you want to go to the sky first, you must be pushed by external forces, such as using thrusters, and after pushing to the right height, you will lose power.

Simple and easy to understand, understand everything, the questioner may be a little incomprehensible, after all, it is necessary to have some formulas to lay the foundation, not to understand at once, do a good job after class, you will definitely understand. When I first came into contact with it, I didn't understand it, and slowly I did more questions, and I was not afraid of this kind of problem.

According to Newton's gravitational formula f=gmm r 2 and the formula of circular motion f=mv 2 r, the minimum orbital velocity can be obtained by solving the two equations in two years, v 2=gm r, g is the constant of gravitational force, m is the mass of the earth, r is the radius of the point, so that a v = can be obtained, as long as the speed of the manned spacecraft is greater than this speed, it can overcome the gravitational force on the earth's surface and fly out of the atmosphere to make a circular motion around the earth.

A manned spacecraft goes into space by using the momentum theorem to overcome gravity (the attraction of the Earth to a spacecraft). The weightlessness in orbit (which is perfectly circular by default in middle school books) is weightless because the direction of gravity is perpendicular to the tangent of the spacecraft's flight trajectory. In fact, the orbits of celestial bodies are generally elliptical (geostationary satellites and other objects are not), and functional relationships are generally used to calculate the speed and altitude and analyze the work done.

The gravitational force to be overcome by the gravitational force of the manned spacecraft is calculated to obtain the propulsion force of the rocket.