# Tag Info

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Yes, the geomagnetic field does rotate with the earth. This is the reason why maps of the geomagnetic field overlaying geographic coordinates are reasonably accurate for a decade or two - and why a compass is still useful for navigation. (i.e. You do not need to know the time of day in order to correct for the magnetic declination cited on your map!) The ...

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Yes, the Earth's magnetic field does rotate with the Earth. There is a simple way and a complicated way to explain this. Firstly the simple way: the magnetic north pole and the North Pole are not at the same point. That means if the magnetic field did not rotate with the Earth the magnetic north pole would rotate once around the North pole every 24 hours. ...

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Skipping the (high-school level) math for a moment, and apply a layer of common sense gives us this: Objects attract each other, inertia depends on mass. Given the mass of the earth is large one can reasonably assume it to be stationary for human-scale purposes. If we are dropping a moon-sized object we may want to consider the earth's motion, but it won't ...

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Newtonian mechanics should be accurate enough. There are general procedures that can help answer the question "is it safe to ignore this effect." See, for example, dmckee's comment. This answer is more of a question-specific approach. The force on the "falling" object by Earth is equal in magnitude to the force on the Earth by the falling object. This can ...

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the trm "weight" in its own mean the net mass of the metal + the gravitational force. we see that the non-metals are not attracted towards magnets. earth, being a giant magnet, attracts metals only. thus, the weight of the non metals is mass + gravitational force on the other hand, metals have higher masses too. so their weight is mass + gravitational force ...

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To measure at a particular location you set up a rain gauge there. There are various technologies. Nearby stations will give you an idea of the rain at the point you want, but neither averaging nor taking the closest will be sure. There can be local effects that increase the rain at a given point. Often the bulk of the rain will come from spotty storm ...

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You go to point D and measure it, otherwise it's only a "best guess".

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Depends on the size of the sun. If it's capable of illuminating the entire surface of the earth at once, then the transition would be sudden. Take a torch, and a coin, and sit in a dark room. Shine the torch obliquely onto one face of the coin. You can then choose whether the coin spins so alternating faces are exposed to the torchlight, or the torch ...

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Well, assuming a lot of things aren't true, then no. For example, if the Earth was shaped like a pizza, and the sun revolved around it, then it would have the same transition.

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According to the shell theorem, there's no gravitational attraction inside a spherical shell of matter. At the center of the earth, its entire mass is arranged around you in spherical shells, so the gravitational acceleration due to the earth is zero. You'd still feel the gravity of the sun and moon and other external objects, as well as a (small) ...

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I'm not a physics expert, but I do know the basics. Gravity is created by mass so all things with mass have gravity. The gravity is negligible in an object unless it is something large like the earth or moon. In the middle of earth, all of the mass should be all around you so you should feel the force of gravity pulling in all directions away from you.

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By my rough calculations, a fall to the center of the Earth will raise the temperature of water by some $7,200 K$. This is extremely hot, but I believe it falls short of a full plasma ionization. Additionally, I would put the pressure at the center somewhere around $30 GPa$. That's a "G", not an "M". I can't even look up properties because these conditions ...

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There would probably be no nice oscillations, it would be rather chaotic and it would be insanely diffcult to calculate exactly. One big question is the incredible temperature in the core which would have significant effects on the whole process. Let's assume the temperature can be somehow isolated by the impossible material that you are using. The water ...

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That's not quite correct. You may have noticed that during summer the days are longer (and the nights shorter) than during winter. That is because the earth's axis is tilted about $23^o$ from the plane of it's orbit around the sun. With this tilt, as the earth travels around the sun the northern hemisphere gets longer days is the north pole is tilted ...

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The 6 months day/night cycle is exactly happening only at the poles (as pointed out in comments). Between the poles and the arctic circle you have a gradual change from 6 month cycle to the 24 hour cycle. Greenland is partially in this area (south Greenland is actually outside the arctic circle). It is happening because the Earth rotational exis is tilted, ...

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First a counter-question as an idea for further thinking: How do you measure Earths weight? On Earth we weigh things using Earth's gravity. Think of it that every little particle creates it's own gravitational field (that's actually true). So every particle there is attracts every other in the entire universe (according to our current equations). So if ...

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any flow is driven by pressure gradient, which must overcome the friction of flow through the tube. It's a very long way, hence huge pressure drop relative to the initial pressure gradient. No flow

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Assuming the tube is insulated along its whole length (which I think is the intent of the question although it's not stated), I think a flow in either direction is stable and sustaining, but there is no particular reason it will form in either direction if the initial conditions are that the air in the tube is still. It will then depend on the average air ...

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In the last few weeks there was an announcement of huge amounts of water being discovered in the upper mantle and crust. It's hard to trust news articles written for common consumption, but it was calculated to be several times as much water as there is in the oceans, just under the United States (not even mentioning the other continents). After 4.5 billion ...

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The gravitational fields of the Sun and the Moon do produce measurable effects on the shape of the Earth. The tidal distortion of the solid Earth (and the liquid outer core) is often referred to as the Earth Tide to distinguish it from ocean tides. The gravitational effects of the Earth tide do cause small strains in the Earth which might influence ...

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Acceleration due to the Coriolis effect: $a_C=−2\Omega\times v$ Then $\Omega=2\pi/day$ $v=45m/s$ and thus $aC=−0.0065m/s2$ Horizontal displacement $d$ is given by $$d=1/2a_Ct^2$$ Using earlier estimate of $5.2s$ flight time for a ~200m drive: $$d=−18cm$$

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