# Tag Info

8

No, it would not be sucked off, for the same reason that the earth has an atmosphere to begin with: gravity. No, for the same reason that Jupiter doesn't have a noticeable pull on you: the strength gravity decreases with the inverse square of distance. No, Gravity is too strong. Your misconception seems to be coming from the idea of a vacuum and a straw. ...

6

The moon always poses the same face to the earth because its rotation period around its axis is equal to its revolution period around the earth. It is this way due to tidal locking. See: https://en.wikipedia.org/wiki/Tidal_locking

5

You ask: what is the exact average distance r we must consider when we determine the centripetal force and consequently the pull of the Earth $v^2/r$, is the semi-major axis 384,399 or rather 384,748 Km, and is average distance 385,000? and, is average speed 1.022 or 1.023 Km/s? Does the pull vary during the revolution? But this is not a well defined ...

4

Earth is not a sphere... So the expression for the gravitational force is not that of a sphere. There are several answers on this site that give the details - See for example this one A simple way to think about this: consider the Earth made up of two components: a sphere, and a "bulge": The total force of gravity at the pole can be thought of as the sum ...

3

All the Sun's power $P$ passes uniformly through a sphere with radius of 1 AU. Calculate the total surface area of this sphere and call it $S$. The Earth's disc also has a surface area that can be calculated from its radius. Call this surface $S_E=\pi R_E^2$. The fraction of the Sun's power received by the Earth is thus: $f=P\frac{S_E}{S}$.

3

Are there any other rivers in the world for which this is true? The Mekong, at least after it has left the Tibetan plateau. Location Latitude Elevation (m) Radial distance (km) Source 33° 42' 30" 5224 6376.8 Manwan Reservoir 24° 45' 15.5" 997 6375.4 Ruak River mouth 20° 21' 16" ...

3

If we have an object of mass $m$ at a distance $r$ from the earth then Newton's law of gravitation tells us that the force between the object and the earth is given by: $$F = \frac{GM_em}{r^2} \tag{1}$$ where $M_e$ is the mass of the earth and $G$ is the gravitational constant. Since the Earth is much heavier than (most) objects near it we can take the ...

2

Since the cosmic rays come from all over and the magnetic field only applies force perpendicular to the direction of the particles' travel, there isn't any polar sorting in the sense of "positive to the north, negative to the south" or vice versa. Magnetic fields are related to electric fields, but they're not electric and don't cause electrical ...

2

The omnipresence of water on Earth is a product of the conditions and matter present on Earth when it began to form billions of years ago. You could call it a coincidence. It is not correct that the amount of water on earth is constantly increasing. Water levels are currently rising, but because of glaciers melting, not because water is somehow being ...

2

If the earth and moon were both stationary initially, the moon would fall into the earth as you said. But they were not. Earth was moving around the sun when the moon was formed from the earth. And so the moon also started revolving around the earth. Infact even now the moon is falling towards the earth, but the earth is continually moving away so that the ...

2

I can give a brief answer, though if anyone wants to do a better, more detailed one, feel free. Sea level at the Equator is 21.36 KM higher than at the poles. Source, and with a distance of about 10,000 KM pole to equator, that's a natural rise moving towards the equator of 2.1 meters per KM. That works out to 2.136 meters per km or a bit over 11 feet per ...

1

A top's precession is caused by torque from the point not being aligned with the center of gravity, this tends to try to get the top to rotate away from the stable axis. In the case of Earth, the oblateness interacts with the sun's, moon's, and Jupiter's gravity to try to align the axis of rotation perpendicular to orbital plane. This is a torque that tries ...

1

It is highly unlikely that there was any nuclear fission in the center of the Earth. For that you need a critical mass of fissile elements. These elements are actinides: uranium, thorium (and if you think of the really early Earth, then maybe a bit of primordial plutonium that has not decayed yet). The problem is that these elements do not reside in the core ...

1

The Foucault pendulum motion is induced via the Earth's rotation. Because it moves it can perform work. I answer Yes, but irt others it may depend on the more or less flexible definition of vast amount and the size and number of pendulums . EDIT ADD to 'debunk' myself: The above statements are correct,imo, but I will decompose the situation. Some ...

1

As all living cells take their matter from the earth, the overall mass stays constant. The earth is (mostly) a closed system with only very few exceptions: Gases, that are light enough to escape the earth atmosphere (I think this can happen to helium) The stuff humans send into space using rockets A (tiny) bit of mass is added to earth by the sun's energy ...

1

That depends on how you found that weight. If it is calculated from the gravitational pull, then all things on earth are included since they add to the mass. If it is calculated through geological measurements then maybe they are not included. In any case, try to multiply 80 kg or so for an average human with 6 billion. Try to add an estimate for ...

1

Because of conservation of mass, the fact that things on Earth are composed of trees, buildings, etc, doesn't matter - the only time the mass of the Earth will change is if things physically leave the Earth. According to this article the major change in the mass of Earth is due to about 10$^5$ kg of Hydrogen and Helium escaping from the atmosphere every ...

1

There would be no net movement of air in such a straw extending from the surface of the Earth to outer space. Perhaps you're thinking that the air at the bottom of the straw is being pushed into the straw with a pressure of 1 atmosphere (14.7 psi) while the top of the straw is at vacuum (0 psi) and so there is a net force pushing the air into outer space? ...

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