If you are using the Earth as a frame of reference, please solve the following questions

1: The Sun rotates counterclockwise from west to east while orbiting the Milky Way counterclockwise.

2 The earth revolves around the sun, so the sun should be regarded as the center of the circle, and the earth moves in a circular motion with the sun as the center.

3.Based on gravitational pull:

mg=gmm R2 near the ground, the centripetal force is approximately equal to the gravitational force.

mg=mv 2 r An object that moves in a circular motion, gravity provides the centripetal force.

f= gmm r 2 = mv 2 r gravitational force provides centripetal force and according to this formula the gravitational force before them can be calculated, etc.

4 The earth and the moon can only be regarded as moons of the sun, and who is the satellite according to who revolves around whom, in order to better distinguish the relationship between the planets, is now often used as "satellite, satellite satellite,..Guards, guards, guards. If the stars are judged by the solar system, because other stars revolve around the sun, the earth is the sun's satellite, and the moon revolves around the earth, so it is the sun's satellite satellite, and the moon revolves around the satellite.

Correct, for example, the motion between the sun and the earth is relative to the self, but the change in position between them, i.e., the distance, is absolute, so it can be seen as a circular motion with the earth as the center. In terms of action and reaction forces, the forces between them are exactly the same, so we can use f=gmm r 2=mv 2 r. The sun and moon can be converted into each other, but it is usually said that the study is based on the earth as a frame of reference, and it can also be said to be a regulation.

The mass of the earth is compared to the mass of the sun, just as your mass is compared to the mass of the earth, and I ask you: are you ignoring the mass of the earth? Or ignore your own quality?

1.The sun moves in a uniform circular motion.

2.OK. 3.The law of gravitation is between two objects, independent of the frame of reference, and can be used.

4.I think so.

What stage is this knowledge?

a.At the beginning of the first grip of the roll, the average temperature of the earth has a margin of more than 1000 bThe thickness of the Earth's core is about 3,400 kilometers.

c.The thickness of the Earth's mantle is about 3,900 km.

d.The average thickness of the Earth's crust is about 17 km.

Correct answer: c

Scientists have proven that there is no second planet suitable for human habitation, at least within the 40 trillion kilometers centered on the Earth.

a "At least" means "least", emphasizing the current scope of research that is limited to 40 trillion kilometres, reflecting linguistic rigor.

b "At least" indicates the minimum limit, meaning that there is no within 40 trillion kilometres, but there must be outside 40 trillion kilometres.

c "At least" is the current maximum, indicating that human exploration of space is unlikely to exceed a distance of 40 trillion kilometresa

a. The frame of reference is to describe the motion of the object, and other objects that are selected as references and assumed to be immobile The objects selected as the accommodating frame of reference can be stationary or moving, so a is wrong;

b. The reference frame is to describe the motion of the object, which is selected as a reference and assumed to be an immovable object, and the convenience of the research problem should be considered when selecting the reference frame, so that the description of the motion is as simple as possible.

c. When studying a simple motion situation, it is also necessary to select a reference system, so C is wrong;

1. The longitude of a direct point is the ** meridian of the day hemisphere.

2. C reference drawing.

1. A The Western Hemisphere is the night hemisphere, the local time is 0 o'clock at 110°W, and the local time at 70°E is 12 o'clock, that is, the meridian where the direct point of the sun is located.

2. C The morning and dusk line coincides with the meridian, and the equinox is a diquinox. It was night right for us, indicating that the date was the day of the autumnal equinox.

It should be the axis of rotation, which does not actually exist inside the Earth.

The Earth's axis is the Earth's oblique axis, also known as the Earth's axis of rotation. Specifically, it refers to the axis around which the earth's rotation rotates, and the intersection point of its northern end with the earth's surface is the North Pole, and the intersection point of its southern end with the earth's surface is the South Pole.

The Earth's axis is the imaginary axis of the Earth's rotation. The Earth is constantly orbiting this imaginary axis. Therefore, it is also called the earth's axis of rotation.

This axis connects the north and south poles through the center of the earth, and has an angle of 66°34 with the Earth's orbital plane. The Earth's axis is facing the North Star. The plane that passes through the center of the earth and is perpendicular to the earth's axis is called the equatorial plane.

The position of the Earth's axis in the Earth is not fixed, but there are small movements, resulting in "pole shifts". The extension cord is the "celestial axis". The two points of intersection between the Earth's axis and the ground are the "Earth's poles". The two intersections of the celestial axis and the celestial sphere are the "celestial poles".

Geologically, the geologic axis is located in the linear uplift zone at the edge of the platform, which is a relatively active positive secondary structural unit within the platform. The term "earth axis" was proposed by Chinese geologist Huang Jiqing in 1945. The folded substrate is widely exposed, and the sedimentary caprock is absent or underdeveloped.

The faults and magmatic activities are relatively strong, the endogenous minerals are also abundant, and the caprock folds are gentle. The geodetic axis is often the boundary between two sedimentary areas with different properties, such as the Inner Mongolia geodetic axis and the Qinling geodetic axis in China.

Extraterrestrial planets are easy at opposition.

It's not easy, but it's inevitable] Retrograde phenomena occur, what about the planets on earth? The Earth's revolution around the Sun (rotation?) Average?

The product of linear velocity and distance? [Sorry, I can't fill it in]) velocity does not change, while (angular velocity linear velocity) velocity changes with the distance between the sun and the earth.

The reason for the diurnal length of the true sun is the failure of the sun, the cause of which is the existence of the yellow-red angle, the sail and the unevenness of the earth's rotation.

The three commonly used celestial coordinates are (horizon coordinate system), (hour angle coordinate system (first equatorial coordinate system)), second equatorial coordinate system), rolling letter (ecliptic coordinate system), (galactic coordinate system) [choose any three].

1) Changes in the speed at which waves propagate within the Earth.

2) Transverse Gutenberg The longitudinal wave suddenly descends and the transverse wave disappears completely.

3) The thickness of the earth's crust is uneven, with the continental crust being thick and the oceanic crust being thin and composed of rocks.

4) D--- liquid H---solid.

Test question analysis: (1) Combined with the diagram, human beings use the change of the propagation speed of **wave speed in the ground to study the inner sphere of the earth. (2) The propagation speed of longitudinal waves is faster than that of transverse waves.

The interface that divides the crust and mantle is the Moho interface, whereas the interface that divides the mantle and core is the Gutenberg interface. Therefore, the B interface shown in the figure is the Gutenberg interface, which can be analyzed by direct reading, and the transverse wave disappears after the Gutenberg surface, and the longitudinal wave velocity decreases. (3) The circle j shown in the figure is located above the Moho interface and is judged to be the earth's crust.

Distribution characteristics of the earth's crust: the continental crust has a double layer and the ocean crust has a single layer. Therefore, the continental crust is thicker, and the oceanic crust is thinner.

And the earth's crust is made of rocks. (4) Figure d is the outer core, and the transverse wave cannot pass through, indicating that it is in a molten state or a liquid state. H is the core and is solid.

Comments: The key to solving this problem is to grasp the propagation characteristics of transverse waves and longitudinal waves, and the main basis and boundaries of the earth's inner sphere, and analyze it with the use of graphical information, which is generally difficult.

There are many differences, now there are more stinky ditches, fewer clear rivers, more garbage, fewer woods, more people, fewer species, more toxic components in the air, and many more holes in the ozone layer... How do you count the lots? It seems that there are countless stars in the sky!