All Questions
Tagged with earth newtonian-mechanics
34
questions
89
votes
9
answers
220k
views
Why doesn't the Moon fall onto the Earth?
Why doesn't the Moon fall onto the Earth? For that matter, why doesn't anything rotating a larger body ever fall onto the larger body?
- 1,033
5
votes
1
answer
7k
views
Is acceleration due to gravity constant?
I was taught in school that acceleration due to gravity is constant. But recently, when I checked Physics textbook, I noted that
$$F = \dfrac{G m_1 m_2}{r^2}. $$
So, as the body falls down, $r$ ...
- 657
56
votes
8
answers
44k
views
Proof that the Earth rotates?
What is the proof, without leaving the Earth, and involving only basic physics, that the earth rotates around its axis?
By basic physics I mean the physics that the early physicists must've used to ...
- 563
4
votes
2
answers
4k
views
Earth-Centered Inertial (ECI) reference frame as approximate inertial frame of reference
In many practical applications, one can consider the Earth-Centered Inertial (ECI) reference frame approximately as an inertial reference system, though strictly speaking, it is non-inertial.
Is ...
- 1,181
8
votes
2
answers
4k
views
Huge buildings affect Earth's rotation?
Does constructing huge buildings affect the rotation of the Earth, similar to skater whose angular rotation increases when her arms are closed comparatively than open?
- 415
1
vote
2
answers
663
views
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
6
votes
4
answers
3k
views
If you could ride an elevator through the earth [duplicate]
What if it was possible to ride an elevator straight through earth. If we take all the heat and pressure problems away, and assume it would be possible: What would happen with gravity? Would gravity ...
39
votes
7
answers
14k
views
Why don't we feel the subtle speed change of Earth's elliptical orbit?
Earth's orbit is a slight ellipse, so to conserve momentum its speed increases when it is closest to the Sun. If the speed changes there is an acceleration. If there is an acceleration there is a ...
- 2,878
13
votes
6
answers
9k
views
Is the Moon in a "Freefall" Around the Earth? [duplicate]
The force of gravity keeps our Moon in orbit around Earth. Is it correct to say that the Moon is in “free fall” around Earth? Why or why not?
I think the answer is yes. The moon is falling towards ...
- 243
28
votes
5
answers
11k
views
Build a ring around Earth, then remove the supports
What would happen if we decided to build a giant ring that managed to wrap around the whole world, end to end that was supported with pillars all along the ring and then the supports all suddenly ...
- 429
20
votes
1
answer
2k
views
If the tidal bulge on the earth speeds the moon up, how does the moon move to a higher orbit?
I understand that the moon causes a tidal bulge on Earth, and this tidal bulge moves slightly ahead of the moon due to Earth's rotation.
When reading about why the moon is moving away from the Earth, ...
- 303
8
votes
3
answers
13k
views
How long was a day at the creation of Earth?
Since the earth is slowing its rotation, and as far as I know, each day is 1 second longer every about 1.5 years, how long was an earth day near the formation of earth (4.5 billion years ago)?
I ...
- 181
8
votes
4
answers
12k
views
Effect on length of day as the polar ice caps melt
If the polar ice caps of the Earth melt, how will the length of the day be affected?
- 247
6
votes
4
answers
3k
views
Can human push Earth away from the Sun?
It's said the earth is approaching the sun. Can we push it away little by little?
Although we can emit rocket towards the sun, but it's too expensive to make a rocket:
So I think maybe we can ...
- 255
3
votes
4
answers
510
views
Should the centripetal force of Earth's orbit around the Sun affect a pendulum on Earth?
Lets use approximate earth angular velocity around the sun with $\omega\approx2*10^{-7}\frac{r}{s}$ and earth translation orbit radius with $r\approx1.5*10^{11}m$ we can approximate centripetal ...
- 33