All Questions
Tagged with earth homework-and-exercises
74
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Centre of Gravity of Earth-Moon Elevator [closed]
Suppose you have a cylindrical elevator that resembles a rod of mass $m$, cross-sectional area $A$ and uniform density $\rho$, with a length $L$ spanning the distance between the Earth and the Moon. ...
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1
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At which colatitude $\theta$ is the error between $\vec g_{eff}$ and $\vec g$ maximum? [closed]
Suppose a plumb bob hangs without swinging, then the string defines the
effective direction of gravity. Suppose you are holding the bob on the surface of the
earth at colatitude $\theta$, where $\...
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Alfven waves in the ionosphere
I was given the following problem/question as a part of my homework in physics:
It is raining with thunder in Australia, and the lightnings generate transverse Alfven waves in the ionospheric plasma. ...
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2
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Would a body have any residual velocity if launched at escape velocity from the Earth's surface?
A body is lanuched at escape velocity from the Earth's surface i.e 11.2 km/s ,what would be it's velocity outside the Earth's gravitational field?
I guess it would be zero but there's another problem ...
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How much time dilation are we experiencing here on Earth? [duplicate]
We experience time dilation from speed and gravity, but we are in more than just the Earth's gravity field, but also the sun's and the galaxy's gravity field and we are both spinning at 1,670 km/h, ...
0
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Problem on Angle of declination [closed]
There was a problem in my book that read- A magnet is pointing towards geographic north at a place where the horizontal component of the Earth's magnetic field is 40 microtesla. Magnetic dipole ...
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2
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375
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Calculate Earth angular speed [closed]
How may I calculate Earth's angular speed at specific point (The green dot for example)?
Note: I know that angular speed $= \dfrac{2\pi}{T}$ But how may I found $T$ in this case?
I found too that $R_{\...
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How high can you jump (at the corner) on Cube-Earth?
I have read this question:
Is the force of gravity always directed towards the center of mass?
And G. Smith's answer lists a site where they specifically talk about this case mathematically.
https:/...
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1
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1
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Deriving gravitational acceleration from the formula for the force of gravity [closed]
I'm trying to derive this $g = 9.8 m/s^2$ from this
$$F = G\frac{m_E\cdot m_2}{(r)^2}$$
So I did:
$$g = G \frac{(5.972\cdot 10^{24}kg)}{(6.371km)^2} \Leftrightarrow \\
g = 6.67\cdot10^{-11}Nm^2/kg^...
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104
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Black hole on Earth, 1 foot in diameter [duplicate]
If a black hole 12 inches in diameter were situated (say) 10 metres off the ground, what would happen?
And how long would it take to devour the earth?
user102490
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Determine Earth's radius with stopwatch at sunset [closed]
This question appeared on Bangladesh physics Olympiad 2014, Sylhet, Bangladesh for students of class 9 and 10.
I really tried to solve this, but I failed. Please help.
Suppose that, while lying on ...
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Earth's surface area
Here we are trying to calculate the earth's surface area via geodetic coordinates:
\begin{align}
x&=(R\,p(\lambda)+h)\sin\lambda\,\cos\phi\\
y&=(R\,p(\lambda)+h)\sin\lambda\,\sin\phi\\
z&...
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1
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How fast would an object at cruising altitude (around 10,600 m) need to travel to stay on the opposite side of the Earth to the Moon? [closed]
I am trying to figure out how fast an object will have to travel (at a height around 10,600 m) to never be in the presence of the moon. Meaning the object will always be on the opposite side of the ...
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2
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1
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102
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How much does NASCAR affect the rotation of the Earth? [duplicate]
Many of us will be familiar with XKCD 162: Angular Momentum, in which someone spins counterclockwise to slow down the rotation of the earth and make the night longer.
The mass of an individual human ...
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What is acceleration due to gravity at the centre of the earth? [duplicate]
When I asked my teacher that what is the acceleration at the centre of earth, he replied that it is 0 as when we move inside the earth, the effective mass decreases i.e. the mass that exerts ...
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