All Questions
13
questions
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votes
1
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21
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Can we treat the entire mass of the spheroid as being concentrated at its center?
I know that to find the gravitational force between two objects, if either of them is a sphere, we can assume its mass to be concentrated at its center and use the formula for gravitational forces for ...
- 69
1
vote
1
answer
88
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What would happen if the Earth rotated at the rate required to achieve orbit at its radius? I.e ~7k m/s instead of ~460 m/s
To achieve a circular orbit, you need to have a velocity of $$v = \sqrt{Gm/r}$$ which is about 7 km/s at the Earth’s radius, but the Earth’s rotational speed is only about 460 m/s (by taking the ...
- 111
2
votes
3
answers
171
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Had the centrifugal force of the rotation of Earth in the past forced liquid, hot Pangea to be positioned near the Equator?
Had the centrifugal force of the rotation of Earth in the past forced liquid, hot Pangea to be positioned near the Equator? Maybe also a question for 'GSE' but if we deal with centrifugal forces and ...
- 1,815
1
vote
1
answer
214
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The Earth's Equatorial Bulge [duplicate]
It is stated that the Earth is a 'squashed sphere' due to the very slight bulge at the equator. (Thought in reality it's such a small difference, it's essentially spherical)
Typical values:
...
- 11
1
vote
0
answers
27
views
Estimation of Equatorial Bulge of the Earth [duplicate]
My dynamics lecture notes repeat the Earth's equatorial bulge can be approximated as:
$$ \approx \frac{\Omega^2R}{g} \approx \frac{1}{300} $$
(Do they mean R/300?)
They also include statements like:
...
- 683
-2
votes
2
answers
346
views
Will the Earth flatten out?
Since the rotation of the earth makes it more flat,due to the centrifugal forces, is it not possible for the force to completely flatten out earth into a plane ?
- 12.5k
1
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0
answers
35
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If Earth spun faster, would I be able to jump higher? [duplicate]
I'm asking mostly in relation to the forces acting on a person, but it would also be nice to know if there would be any impact on muscle strength, similar to when an astronaut goes into space.
- 11
0
votes
1
answer
250
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Why is the weight of a constant mass different on the poles and on the equator? [duplicate]
I know of an explanation that the Earth is a inertial frame of reference since it is rotating about its own axis, and since this is happening there is a centrifugal "force" or effect which counters ...
- 332
0
votes
2
answers
105
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Can we decrease the value of $g$ (gravitational pull) without gaining height? [closed]
The value of $g$ on earth surface is $9.8\ \text{m/s}^2$ and when we gain height, then the value of $g$ decreases. Pilots experience same phenomena in air, but can we decrease the value of $g$ by ...
0
votes
5
answers
1k
views
Why is Earth's gravitational pull only at its center?
Why is Earth's gravitational pull only at its center?
Does acceleration due to gravity remain constant wherever I go in and on the Earth?
- 11
20
votes
5
answers
136k
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Why is Earth's gravity stronger at the poles?
Many sources state that the Earth's gravity is stronger at the poles than the equator for two reasons:
The centrifugal "force" cancels out the gravitational force minimally, more so at the equator ...
- 517
5
votes
2
answers
9k
views
How would gravity change on a planet rotating around itself very fast?
Let's take a planet identical to Earth, but with rotation speed multiplied by ten thousand. What would happen with the gravity if it was spinning madly around itself? Would the centrifugal force make ...
- 1,281
10
votes
4
answers
3k
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How do we know that Earth is not perfect sphere?
I've just read here that:
Equatorial radius = 6378.16 kilometers. Polar radius = 6356.78
kilometers, so the difference in circumference is 71.1 kilometers. It
is not a perfect sphere, but kind ...
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