All Questions
9
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How does a mass ejected at escape velocity keep moving till infinity?
I've studied that if a mass is ejected from the surface of the Earth at 11.2 km/s (or at any point above the surface at a lower Ve), it 'escapes' to infinity.
Does that not imply a violation in the ...
- 93
0
votes
4
answers
177
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What happens if a projectile is projected with escape velocity but not upwards?
This may be a dumb question, however I was confused with escape velocity and in the end determined that escape velocity is based off of energy, whereby (i think assuming air resistance and all that is ...
- 521
3
votes
4
answers
3k
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Why is the mechanical energy of a free falling object conserved?
My textbook says that in an isolated system (when there is no external force and the internal forces are conservative)the mechanical energy of the system remains constant.
It then states the example ...
-1
votes
6
answers
657
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How is speed affected (or not affected) by acceleration by gravity?
I am a new physics student and I was reading a question posted on here earlier:
Which Sphere is Fastest?
It posits that three spheres thrown with the same speed at the same point (one thrown ...
11
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3
answers
6k
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Which sphere is fastest? [closed]
I was doing a physics problem, and it seemed simple at first, but now it doesn't at all, and I need help. Here it is.
Three identical spheres are thrown from the same height above the ground. Sphere ...
- 113
0
votes
1
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3k
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Escape velocity of the solar system?
I'm having a lot trouble with this problem. I need the minimum escape velocity for the (earth sun) solar system. I can't simply integrate the potential with respect to radius since this changes with ...
user86425
0
votes
3
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450
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Why do we get 2 different answers for escape velocity, when we apply different laws to calculate it?
To measure the escape velocity, if I use the equation -
$$\frac{-GMm}{r^2}=\frac{v.dv}{dr} $$
and I put my final distance to be $\infty$ , then I get the answer,
$$u = \sqrt\frac{2GM}{R} \;. \...
- 1,770
-1
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3
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4k
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Will a body necessarily posses zero kinetic energy at infinity?
I have been studying about gravitation for a while and most of the books(including fundamental of physics) while defining escape velocity assumes that kinetic energy of a body at infinity is zero (...
- 1,829
1
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2
answers
2k
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What is the most efficient machine for translating gravitational potential energy of one mass into kinetic energy of a different mass?
As the question states, what is our current best machine for translating falling gravitational potential energy, such as a large weight, into launching a smaller projectile vertically? A lever? A ...
- 3,241