Gravitational force gravity centripetal force or gravitational force support force centripetal force

1.When the rotation of the earth is not considered, i.e., the angular velocity of rotation w=0The centripetal force f=mrw 2=0, at this time gravitational force = gravity, this situation generally occurs in rough calculations when the satellite orbits the earth.

So we think that near the surface of the earth, gravitational force and gravity are equal.

2.At the poles, the centripetal force is also 0, at which point gravitational force = gravitational force.

3.When considering the rotation of the earth, that is, the centripetal force is not 0, and the centripetal force f=mw 2*r, the objects on the surface are all rotating with the earth (except for the two stages), so the angular velocity w of rotation is the same, but the radius of rotation is different. For example, the radius of rotation of an object in Beijing is smaller than that at the equator.

At this point, the gravitational force is decomposed, and one component provides the centripetal force, and the other component is what we often call gravity. It is precisely because the centripetal force is different in different dimensions that the gravitational acceleration g is also different in different places, which is the reason mentioned above. This situation usually occurs in questions such as what would happen to objects at the equator if the w of the Earth's rotation suddenly increased one day.

When on the equator, the gravitational force and its two components: gravity and centripetal force are in a straight line, so gravitational force = gravity + centripetal force, because the gravitational force on the object remains unchanged, at this time w becomes larger, then the centripetal force f becomes larger, so the gravitational force on the object becomes smaller, when gravitational force = centripetal force, gravity = 0 at this time, that is, at this time the object has no pressure on the ground, and the object will float up.

Gravitation = gravity + centripetal force, this note is vector synthesis, not algebraic addition. If you are at the equator, you can add algebraically.

In the process of general calculation, since the centripetal force is much less than the gravitational force, it can be considered that gravitational force = gravity.

The gravitational force of man standing at the poles of the earth is equal to the key centripetal force, and the resultant force of the heavy empty force and the centripetal force is the gravitational force centripetal force m(2 faction t) 2r

Gravitational attraction is the attraction between substances with mass and is real.

Centripetal force is not a specific force, it is just a concept, its function is to change the linear motion of the object and form a circular motion (or curvilinear motion), and the centripetal force is not a specific grip force, and there is no such thing as centripetal force in nature. The centripetal effect (so to say emphasizing that the centripetal force is not a specific force) requires a specific force to provide, for example, in celestial motion, the centripetal effect of a circular motion is provided by gravity.

I don't know if I made it clear.

For ease of understanding.

I will explain it in three cases.

When the object is on the surface of the earth, at this time the object in Zhenzhou is subjected to gravitational force and has two components, but as the landlord said, the centripetal force is small and negligible, so gravitational force = gravity.

2.When an object (such as an aircraft, a satellite, or something) orbits the earth, the gravitational force acts as a centripetal force, so the gravitational force = centripetal force.

3.When an object comes to a halt above the earth and does not orbit it, everything is as simple as gravity = g

1 In practice, Equation 1 can be used for any calculation you can see, and only for objects on Earth can be used for this formula, but not Equation 2, which is interchangeable after leaving the Earth.

2. When ignoring the rotation of the earth, because there is no centripetal force, the gravitational force and gravity are equal, if there is a rotation of the earth, then the gravity of other places on the earth except the pole is about equal to the gravitational force, because the centripetal force is much smaller than the gravity, it can be ignored, but small does not mean that there is none, so it is accurate to say that it is about equal.

3 The third question is that you are confused, gravitational force is the resultant force of centripetal force and gravity, this sentence is true, you first think about what gravity is? Is there gravity in space? So the scope of application of this sentence is on the earth, note that it is on the earth, and the interchange you say is in space, not on the earth, in space, according to the idea on the earth, gravity is equal to gravity, but there is no gravity in space, because gravity acts as a centripetal force, so since a=b, a=c, so a=b=c, that's why they are equal.

4. Objects near the surface of the earth are subject to gravity, and they are not subject to gravity in space, as long as they are near landmarks, they must be subject to gravity, and those moving around the earth are not subject to gravity, and they are subject to gravitational force, as for the derivation formula, you can understand that gravity is equal to mg outside the earth, where g does not refer to but refers to the centripetal acceleration of the point.

To add: why is it said that gravitational force is equal to centripetal force equals gravity, you can understand it this way, gravitational force is the resultant force of gravity and centripetal force on the earth, gravity does not exist in space, so gravity completely acts as a centripetal force, but at the same time, the centripetal force required to follow the rotation of the earth does not exist, so it is considered that gravitational force is equal to gravity, so all three of them are equal.

This question is not difficult to explain.

1.These two formulas can indeed be combined, because the centripetal force is only an effect force, not a separate force, and it is important to understand that the problem you are encountering may be due to the gravitational force as the centripetal force, so it can be used together.

2.This is just a matter of linguistic imprecision, because there are other influencing factors to consider, which is ideally feasible.

3.This problem is similar to the previous two because objects are only subject to gravitational force, while gravitational force on Earth can be approximated as gravity.

4.All objects are subject to gravitational pull, which is fundamental. Perhaps high school textbooks assume that the gravitational pull (gravity) of the Earth in distant space is negligible.

Objects moving around the earth are affected by gravity. You say that gravity is equal to zero and that gravity acts as a centripetal force? , you can give me an example.

If you don't know anything, you can ask.

1.Equator on the Earth's surface.

The centripetal force is the resultant force of the ground support force and the external gravitational force.

2.Polar on the Earth's surface.

There is no centripetal force because there is no circular motion, and gravity is an external gravitational force.

3.Anywhere on the earth's surface.

With the exception of the polar regions, the centripetal force is the resultant force of the supporting force and the external gravitational force.

1.The position of a near-Earth satellite over the equator.

2.Near-Earth satellites are located over the polar regions.

3.Near-Earth satellites are in any position.

The same as in the three cases, gravity and centripetal force are essentially external gravitational forces. The satellite has a gravitational force from outside, and this force can also be called gravity, which also acts as a centripetal force. These are 3 forces, but they are actually different naming methods in force 3.

The gravitational acceleration at high altitude is greater than that of the near-Earth, which can be pushed out by circular motion.

**Substitution g=gm r 2 in g is the acceleration of gravity, both are applicable, so add ** substitution.

If g is the acceleration due to gravity, then isn't mg equal to gmm r 2, i.e., gravity is equal to gravitational force? Yes, gravity is the gravitational force (if you weigh the mass of an object in a spaceship with a spring, the spring scale reads 0) and acts as a centripetal force.

Figuring out the relationship between the three is very simple. If you still don't understand, it is recommended to buy a copy of "Learning Master" for reference, which is very good, as long as you take the time, physics is very simple.

1.A celestial body moves in a uniform circular motion around another central celestial body. Its centripetal force is provided by the gravitational force.

That is, F-lead = GMM R 2 mg = MA direction, and A direction = V 2 R = W 2R=VW = (4 2 T 2)r = 4 2F 2R, so the application of the law of gravitation to solve the related problems of celestial bodies mainly has the following metric relationships: F lead = GMM R 2 (R is the orbital radius) = MG=MA direction = MV 2 r = MW 2r = M = M 2 R = M 2 T 2 r = M4 2F 2R

2.Gravity is a component of gravity, and the analysis of this problem should be carried out from the earth to the hand. Due to the rotation of the earth, the objects on the earth move in a circular motion, the centripetal force f1 = mrw 2 = mrw 2cosa, f1 is provided by the gravitational force f, it is a component of f, cosa is the cosine value of the angle between the gravitational force f and the equatorial plane, and the other component f2 of f is the gravitational force on the object, i.e., f2=mg

It can be seen that the gravitational pull of the earth on the object is the reason why the object is subjected to gravity, but the gravitational force is not exactly equal to the gravitational force, which is because the object rotates with the earth and needs a part of the gravitational force to provide the centripetal force.

3.For an object in the plane of the equator, the gravitational force and the gravitational force are equal, satisfying the mg=f+f direction at the equator (the object is affected by the gravitational force and the supporting force fn of the ground on the object, and its resultant force acts as a centripetal force, and the magnitude of fn is equal to the magnitude of the gravitational force of the object).

When fn=0 over the equator, it is strict, gravitational force = gravity = centripetal force, and the other component of gravitational force in other locations is very small, and it is generally ignored without special instructions.

4.All are subject to gravity, depending on the specific situation, "Why is gravity equal to zero, and gravity acts as a centripetal force" Where do you see it? Gravity is the result of gravity.

Gravity is always present around the Earth, no matter what movement you do. Gravity = gravitational force = required centripetal force.

The attraction of the earth to an object is the gravitational force experienced by the object, which is the resultant force of gravity and centripetal force, at the equator, these three forces are collinear, so gravitational force = gravity + centripetal force, so these three forces are equal and not true.

The centripetal force is the resultant external force directed towards the center of the circle or the center of curvature when the object moves along a circular or curvilinear orbit. Because of the rotation of the earth, the centripetal force required for the objects on the earth to move in a circular motion is provided by a part of the gravitational force.

The gravitational pull of the earth on the object is the reason for the gravitational force of the object, but the gravitational force is not equal to the gravitational force, because the earth rotates, so the gravitational force has to be divided into a part to provide the centripetal force required for the rotation. At the pole, the centripetal force is 0, at which point the gravitational force is equal to the gravitational force. At the equator, gravity is the difference between the gravitational force and the centripetal force.

In other positions, gravity, gravitational force, centripetal force conform to the parallelogram law of force. Therefore, the gravitational force of an object increases with latitude, with the smallest at the equator and the greatest at the poles.

1.First of all, it is clear that the cause of gravity is the resultant force of the gravitational force of the earth and the centripetal force required for the rotation of the earth at the location, and because the centripetal force is smaller than the gravitational force and the gravitational force, it is often ignored in the calculation, so the gravitational force and gravity are approximately equal. In the second case, gravity acts as a centripetal force, in which case gravity does not affect the circular motion of the object when the object is in a circular motion during the motion of the object, and the equation is true.

2.Ignoring the rotation of the Earth, where gravity itself is generated by gravity, the first statement is a description of the nature of gravity and gravity. In the second case, gravity is approximately equal to gravitational force because the centripetal force required for the rotation of the earth is negligible compared to gravity and gravitational force, which is a definition of the magnitude of the two.

3.In this case, assuming that the three quantities are in the same direction, it is impossible to achieve equal magnitude of the three. Therefore, the equation defines the equality of quantities, and in this case using the diagram of the force, there is only one possibility that the three forces are in a regular triangle.

In this case, we know that the Earth's rotation is perpendicular to the direction of rotation, the gravitational force is directed towards the center of the Earth, and gravity is the resultant force of both. This is only possible here for specific locations. (Personally, I don't understand the relationship between time and don't draw a diagram carefully, and I don't know if this situation can be found on the earth for a specific analysis).

4.It can be said that the earth's surface is affected by gravity, which points to the center of the earth, and gravity is zero only when the gravitational force is completely acting as the centripetal force of the earth. From this, it is known that such a place cannot be found, so it is subject to gravity whether it is squeezed or not, and the direction of gravity is always vertical and horizontally facing downward.

Celestial bodies moving around the Earth are subjected to the gravitational pull with the Earth as a centripetal force, so the celestial bodies move around the Earth and are not affected by gravity. gm earth m day r2 = m day v2 r, and the gm ground here is unknown, therefore, we use the method of ignoring the centripetal force of the motion of the object on the earth in the operation, where the gravity is equal to the gravitational force, mg = gm m r2, where m is eliminated, and then we know that the value of gm ground is substituted into the first calculation formula to solve.

The centripetal force is named according to the effect, it is the net force of the object in circular motion pointing to the direction of the center of the circle, for the uniform circular motion back, the centripetal force is also the net force of the object, in the circular motion of a celestial body (or satellite), the centripetal force is provided by the gravitational force;

Gravitation is a qualitative force, a mutual attraction that exists between all objects.

Gravitational force acts as a centripetal force only in the circular motion of a celestial body (or satellite) around the central celestial body, and it is related to the centripetal force.