A question about gravity! Questions about the direction of gravity. Solve! ）

The earth is also subject to gravitational pull, and the object applying force is the same as the object subjecting force, and all objects are objects applying force.

For example, if a person stands on the earth, and the earth exerts gravity on the person and the earth exerts pressure on the person, the two are the same size and opposite to each other, so the person stands still on the earth. On the contrary, people also have a gravitational pull on the earth, and at the same time, there is pressure on the earth through the earth, and the two are also the same size and opposite directions.

The gravitational force is equal for the object applying the force and the object receiving the force, but the reaction of an object to the force is inversely proportional. So when there are two objects, one hour old, the larger object is approximately stationary and the smaller object is attracted to motion by the larger object.

When the Earth is a force object, the force is applied to an object near the Earth.

Forces interact with each other, and when two objects attract each other, either of them is the object exerting force on the other, and vice versa.

If you consider only this pair of interaction forces.

According to Newton's third law, if any object near the earth is subject to gravity, which is the force of gravity, then the earth is subject to the gravitational pull of these people on him.

When the force is applied, the object outside the earth is the gravitational force.

Gravitation only applies to the macroscopic range!

The earth is under pressure from you. The pressure is related to the mass and the small g.

All the planets in space have a gravitational pull between them, and there is a kind of equilibrium between them.

There are two main points in your question:

The gravity you are talking about will not be in the same direction as the gravitational force." This sentence is not entirely true, the gravitational and gravitational direction of objects on the equator is the same, both point to the center of the earth; For the rest of the place, gravity does have a different direction from gravity, but the rotation of the earth is very slow, and the centripetal force required for rotation is very small (that is, the green component in your diagram is very small), so that gravity is almost the same direction as gravity, so we approximate that the gravitational force experienced by the object is equal to its own gravity.

As for the question of "straight down". Which direction is straight down, according to your question, you already think that straight down is the direction to the center of the earth, so you always feel that there is a contradiction between the two. In fact, the direction of vertical downward and the direction of gravity are two mutually defined directions, that is, the objective direction of gravity, we call it vertical downward; In other words, vertical downward is the direction in which gravity is pointing.

Centripetal force and gravity both have specific data, centripetal force is much smaller than gravity, so generally speaking, the gravity of the object is equal to the magnitude of gravity, and ignore the centripetal force caused by rotation, as for gravity vertical downward, it refers to the vertical horizontal plane, when the earth is regarded as a perfect sphere, gravity can be said to point to the center of the earth (that is, the tangent perpendicular to the ball line), your Figure 1 has actually made it clear that the earth is not a perfect sphere, so it cannot be said that gravity points to the center of the sphere, it can only be said that it is perpendicular to the horizontal plane.

As long as the Earth is rotating, then it is not a positive sphere and can be approximated as an ellipsoid. However, the direction of the normal at any point of the ellipsoid does not necessarily point to the center of the ellipsoid. The direction of gravity is equivalent to the direction of this normal, but not to the center of the earth.

1. If the object is on the surface of the earth, the direction of gravity is vertically downward, and the centripetal force is directed towards the earth's axis and perpendicular to the earth's axis.

2. If the object is above the earth and moves in a circle around the earth, then the gravitational force is centripetal force, and the direction of gravity is the same as the direction of the centripetal force, both pointing to the center of the earth.

3. The force experienced by the object when it moves in a curve is called centripetal force--- and further study will know that it is also called normal force. The force exerted on an object in a straight motion is called tangential force. That is to say, the terms "centripetal force" and "tangential force" are divided according to whether the path of motion of the object is curved or straight.

Gravity, friction, pressure, and gravity are divided according to the nature of the force. Both of them can be used as "centripetal forces" or "tangential forces".

4. The force that arises due to the attraction of the earth is called gravity. Direction: Straight down. 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, the objects in other places on the ground are moving in an approximate uniform circular motion around the earth's axis together with the earth, which requires a centripetal force directed perpendicularly to the earth's axis, and this centripetal force can only be provided by the earth's gravitational force on the object, and we can decompose the earth's gravitational force on the object into two components, one component f1, which points to the earth's axis, and the magnitude is equal to the centripetal force required for the object to move in an approximate uniform circular motion around the earth's axis; The other component, g, is the gravitational force on the object.

where f1 = mw2r (w is the angular velocity of the earth's rotation and r is the radius of rotation of the object), it can be seen that the magnitude of f1 is zero at the poles, increases with the decrease of latitude, and is the maximum f1max in the equatorial region. Because the centripetal force of the object is very small, in general, it can be approximated that the gravitational force of the object is equal to the gravitational force, that is, the influence 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 following is a personal opinion, don't spray if you don't like it, thank you.

I think that pointing vertically down and pointing to the center of the earth is the same thing, except that one is a part and the other is a whole, as shown in the figure below

The direction of gravity is indeed "straight down". But the landlord said that because of this, everyone on the equator fell, which was wrong. Because vertical downward refers to the direction of the center of the sphere pointing towards the Earth, and at any point on the surface of the Earth, the direction of gravity is directed towards the center of the Earth's sphere, so people on the equator will not fall.

Your language must be bad, vertical downward is a direction relative to our subjective cognition. That is, a relative direction. Pointing to the center of the ball is a strict direction.

I'm pointing down in different locations on the planet, pointing to different locations. And I'm pointing to the center of the ball at different points on the earth, and there's only one center.

We stipulate that the direction of gravity is vertically downward, and because the earth is relatively large, the earth's surface is approximately flat, so we think that the direction of gravity is perpendicular to the ground, but not to the center of the earth.

And that's the basic concept of physics, and the direction of gravity is straight down, not toward the center of the sphere, because the Earth is an ellipse, and if you follow it, how does it refer to the center of the sphere, and gravity is omnipresent.

To understand the definition as a theorem is to confuse yourself. The theorem needs to be proved, and if you understand the proof process, you will understand the theorem, while the direction of gravity is the definition, which is artificially prescribed, just like giving a person a name, without understanding.

The gravitational force on the object g=mg=5kg

The gravitational force exerted by the object is exerted by the Earth, and it is called straight downward

Therefore, the reply is: 49n; Vertical Qing Lakai straight down

The direction of gravity is vertically downward, and the point of action of gravity is called the center of gravity

So the answer is: straight down; Center of gravity

The result of this question can be estimated, and the analysis process is as follows.

The velocity of the person who has just fallen to the ground by v 2=2gh is v = root number (2gh) = root number (2* m s

The mass of a person is 200 catties, that is, m=100kg

The collision time between a person and the ground when he lands is generally about a second, and finally the speed of a person is zero, according to the momentum theorem.

f- mg）* t=mv

f- 100*

f=1820 Newtons.

It can be seen that the impact force between the person and the ground when he lands is about 1820 Newtons, which is equivalent to 182 kilograms of force, or 364 kilograms of force.

Based on my high school knowledge, we need to know how long it takes to collide with the ground when we land.

The weight is the same when landing. Or 1000n

This is the trajectory of the flat throwing motion.

Vertical free fall.

Horizontal and uniform straight lines.

Look at the circle in my diagram is gravity.

We often use the formula g=mg to calculate the magnitude of gravity, in which g is also called gravitational acceleration, and its magnitude is related to its position.

On Earth, we generally take g = , that is to say, when calculating the gravity of an object on Earth, we generally take the value of g.

But on the Moon, g month = g 6, that is, when calculating the gravitational force of an object on the Moon, the value of g should be 1 6 of g ground.

Whether it is the Moon or the Earth, the mass of an object is constant. The reason why gravity is changing is because it is affected by g.

Wrong, the "direction" of gravity is not a physical quantity, it is inappropriate to say that it is equal, it should be said to be the same, but in different regions, the direction of gravity on objects is not necessarily the same, because the direction of gravity is "vertical downward", that is, pointing to the center of the earth, and the earth is a sphere, obviously these Richon Zheng and rough directions cannot all be the same.

The direction is the same ...The direction of gravity is always straight downwards on Earth.

If it is generally true, always straight down.

Like this picture, the person looks at the water as if it is flowing upward, and you look at it obliquely. But in reality the water flows downwards for the vertical ground. It doesn't matter if the person is a little slanted, as long as it is not perpendicular to the real ground, there is an angle so that the water flows down for the real ground, but upwards for the ground inside the house.

As for the clock, it is completely possible to get you a fake, and a clock designed like this to increase credibility is a hypocrisy.

Fan lanyards? The second hand doesn't move? Is it related to magnetic fields? This may be just one of the principles, there must be something else ... Don't think too far away, get closer to the principles of science...

My personal guess is that the geological anomaly in this area causes the gravitational acceleration g to be perpendicular to the slope, and the g value is greater than elsewhere making the second hand gravity greater than the dynamics.

It is an illusion, because the ground in the room is not actually flat, there is an angle of 30 degrees to the ground, the wall is not perpendicular to the ground, there is a 30 degree angle to the ground, you can't see the outside after you enter the room, you feel that you are standing upright, in fact, you are standing on an inclined plane at an angle of 30 degrees, and everything has a 30 angle to the ground.

The 3rd floor makes sense.

The water and the ball go "high", and in fact the center of gravity is lowered.

Feeling uncomfortable is caused by the fact that the balance receptors in your middle ear contradict the information that your vision transmits to your brain, and it is very easy to get tired.

This will make you lose your sense of balance and direction (you can also do the same if you turn in a fast circle on the spot) as for the second hand. It should be that there is a lot of friction at the fulcrum of the pendulum, and the pendulum will make a damping motion with a lot of resistance.

The second floor is complete, and the gravity is on the high side, which only makes the pendulum swing faster.