All Questions
Tagged with earth homework-and-exercises
74
questions
10
votes
3
answers
226
views
How much additional light does Earth receive from the Sun due to Earth's gravitational field?
I was reading about how gravity affects light, and that got me wondering how much additional light is collected by the Sun due to the Earth's gravitational field.
Is it a significant amount of light (...
- 203
0
votes
2
answers
289
views
If earth stopped spinning how much heavier would 1kg feel [closed]
My girlfriend seems to think if the earth stops spinning we will all fall off
However, she did spark my imagination, due to centripetal force things must feel lighter then they otherwise would on an ...
user68437
-3
votes
1
answer
115
views
Physics Riddle - Know Plant Earth [closed]
I hope it's OK to ask here, because it's pretty much as basic as physics can get. So here it is:
I have a hot air balloon that can rise to any altitude I'd like, a precise watch, a sandbag, a weigh ...
- 111
0
votes
1
answer
59
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Why do we have to use an integral in this scenario to figure out $v_{max}$? [duplicate]
$$\int_0^R mg\frac{r}{2}dr=\frac{m}{2}v_{max}$$ and can't write $$\frac{m}{2}v_{max}=mgR$$ don't we usually equal potential energy to kinetic energy?
A stone is falling through a tunnel towards the ...
- 109
6
votes
1
answer
453
views
How much effort would be required to fix the Earth's rotation?
Given that the earth's rotation has been slowing down by very slight amounts over time, forcing us to introduce leap seconds and so forth into our clocks and calendars, I would like to ask if this ...
- 216
13
votes
1
answer
6k
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How much power would be needed to make a substitute for natural Earth magnetic field?
Imagine the Earth's magnetic field will take a "maintenance pause" for 1000 years and there is a giant 10-year "doomsday countdown timer" ticking in the sky. The magnetic field will be just normal for ...
- 239
1
vote
2
answers
663
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7 Billion people jumping at once
What would happen if every person in the world gathered at a minimum possible area and jumped all at once? Would that have any effect on Earth?
- 2,983
1
vote
1
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From Paris to ... London [closed]
(Excuse the pun in the title, couldn't resist)
Paris and London are connected by a straight underground tunnel, as shown in the diagram below. A train travels between the two cities powered only by ...
- 3,569
2
votes
1
answer
391
views
How much energy is necessary to set a year to exactly 360 days
How much energy would be necessary to slow down Earth rotation such that a year was 360 days long?
In the same spirit: how much energy would be necessary to make the Earth rotate faster around the ...
- 263
21
votes
3
answers
11k
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How quickly was the Earth rotating 250 million years ago?
The Earth is slowing at a rate of $4.7\times10^{-4}$ miles per second every 100 years due to tidal forces of the moon.
See:
http://en.wikipedia.org/wiki/Earth%27s_rotation
http://imagine.gsfc.nasa....
- 311
0
votes
0
answers
166
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Why doesn"t centrifugal force throw us off the earth? [duplicate]
I was drawing a diagram and trying to resolve all the forces. It seems to me that because of gravity, centrifugal force will produce a sort of "dragging" motion along the surface of the earth. The ...
- 533
0
votes
1
answer
546
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Earth's magnetic field
I'm dealing with a problem here. Today my professor asked us a question :
How should a metallic wire move in Earth's magnetic field such that she gets maximum potential difference in it's ends:
a) ...
- 145
5
votes
1
answer
4k
views
Duration of Satellite orbit in the shadow of the Earth
I want to determine how many minutes a satellite is in a circular orbit around the Earth at about $1000 km$ altitude. I assumed that the Sun-Earth vector lies exactly in the orbital plane of the ...
- 65
-5
votes
1
answer
408
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How can I destroy earth with physics? [closed]
I want to destroy the whole earth using physics, I would like to learn some of the ways that can be used to achieve this. I tried using a nuclear bomb but it takes so long, and I can't wait that much: ...
- 521
6
votes
4
answers
182
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Bulk flow of air in a long tube between Antarctica and Australia?
I have a 5km diameter clear plastic tube which is open at each end and runs from the center of Antarctica to Lake Eyre in Australia. The tube is on the ground where it can be and at sea level on the ...
- 2,421