0 Members and 1 Guest are viewing this topic.
Quote from: Thebox on 10/04/2018 10:13:56Quote from: Yahya on 10/04/2018 09:03:51What about this problem ?If the mass m is at infinity then the distance between them is also infinity it is logical if the distance r=∞ that both masses are at infinity, a distance to reach infinity should extend from both directions in order for it to reach infinity, if it extends from one direction the mass m will go forever and the limit can't be approached. if the distance r did not reach infinity then the mass m did not in fact reach infinity and the equation won't satisfyfrom my Op"nothing reaches infinity but when supposing that infinity is a point then the origin 0 should also be a point at minus infinity "My claim that " a distance to reach infinity should extend from both directions in order for it to reach infinity" is completely logical and simple, may someone tell me if I'm wrong?The idea of infinitely is it is endless, nothing can reach infinitely. I can rewrite my claim mathematically as "a distance r approaches infinity should approach infinity from both endpoints"
Quote from: Yahya on 10/04/2018 09:03:51What about this problem ?If the mass m is at infinity then the distance between them is also infinity it is logical if the distance r=∞ that both masses are at infinity, a distance to reach infinity should extend from both directions in order for it to reach infinity, if it extends from one direction the mass m will go forever and the limit can't be approached. if the distance r did not reach infinity then the mass m did not in fact reach infinity and the equation won't satisfyfrom my Op"nothing reaches infinity but when supposing that infinity is a point then the origin 0 should also be a point at minus infinity "My claim that " a distance to reach infinity should extend from both directions in order for it to reach infinity" is completely logical and simple, may someone tell me if I'm wrong?The idea of infinitely is it is endless, nothing can reach infinitely.
What about this problem ?If the mass m is at infinity then the distance between them is also infinity it is logical if the distance r=∞ that both masses are at infinity, a distance to reach infinity should extend from both directions in order for it to reach infinity, if it extends from one direction the mass m will go forever and the limit can't be approached. if the distance r did not reach infinity then the mass m did not in fact reach infinity and the equation won't satisfyfrom my Op"nothing reaches infinity but when supposing that infinity is a point then the origin 0 should also be a point at minus infinity "My claim that " a distance to reach infinity should extend from both directions in order for it to reach infinity" is completely logical and simple, may someone tell me if I'm wrong?
Quote from: Yahya on 10/04/2018 10:24:12Quote from: Thebox on 10/04/2018 10:13:56Quote from: Yahya on 10/04/2018 09:03:51What about this problem ?If the mass m is at infinity then the distance between them is also infinity it is logical if the distance r=∞ that both masses are at infinity, a distance to reach infinity should extend from both directions in order for it to reach infinity, if it extends from one direction the mass m will go forever and the limit can't be approached. if the distance r did not reach infinity then the mass m did not in fact reach infinity and the equation won't satisfyfrom my Op"nothing reaches infinity but when supposing that infinity is a point then the origin 0 should also be a point at minus infinity "My claim that " a distance to reach infinity should extend from both directions in order for it to reach infinity" is completely logical and simple, may someone tell me if I'm wrong?The idea of infinitely is it is endless, nothing can reach infinitely. I can rewrite my claim mathematically as "a distance r approaches infinity should approach infinity from both endpoints" Any given point X is a singularity, you can't approach infinite.
a distance to reach infinity should extend from both directions in order for it to reach infinity
Where you come unstuck is if you want to work out the energy to launch a rocket to a distance of 1, and then you move the Earth to position -1. The distance is now 2, which is not what you were trying to work out...
U= − GMm/rThe first mass m is supposed to be at infinity that means it exerts some potential energy U to escape from the surface of mass M with radius r and approach infinity , when mass m is at infinity mass M is also should be at infinity with respect to mass m, that to be said , mass m won't reach infinity unless mass M reached infinity as well, the point of calculating potential energy is between two infinities, at these two infinities both masses lies .The correct way to calculate mass m potential energy is using definite integral again from minus infinity to infinity in that case :
Quote from: Bored chemist on 09/04/2018 21:44:06You do know they also launched from the Moon, don't you?aerospace engineers would launch rockets at speeds much higher than the escape velocity to avoid the minimum value, giving much higher kinetic energy making the equation of potential energy unnoticeable. however what I think they use ultra higher speeds than that as part of developed spacecrafts designs for faster speeds and not wasting their time.Quote from: Bored chemist on 09/04/2018 21:44:06Face it, they would have noticed if they found it took twice as much fuel or half as much as they expected.aerospace engineers also use much fuel for energy losses as well as much fuel for ultra high escape velocity .Energy losses are much higher than the double amount you are talking about and is from earth due to air resist and energy losses. from the moon it would take less fuel , but forget about ultra high speeds, if they do not have values for the equation on earth how they would compare it on the moon?unless there is an actual test for the equation, do you have evident information for an actual test?
You do know they also launched from the Moon, don't you?
Face it, they would have noticed if they found it took twice as much fuel or half as much as they expected.
Quote from: Yahya on 10/04/2018 07:55:28Quote from: Bored chemist on 09/04/2018 21:44:06You do know they also launched from the Moon, don't you?aerospace engineers would launch rockets at speeds much higher than the escape velocity to avoid the minimum value, giving much higher kinetic energy making the equation of potential energy unnoticeable. however what I think they use ultra higher speeds than that as part of developed spacecrafts designs for faster speeds and not wasting their time.Quote from: Bored chemist on 09/04/2018 21:44:06Face it, they would have noticed if they found it took twice as much fuel or half as much as they expected.aerospace engineers also use much fuel for energy losses as well as much fuel for ultra high escape velocity .Energy losses are much higher than the double amount you are talking about and is from earth due to air resist and energy losses. from the moon it would take less fuel , but forget about ultra high speeds, if they do not have values for the equation on earth how they would compare it on the moon?unless there is an actual test for the equation, do you have evident information for an actual test?If you're talking about the escape velocity equation, then why did you post the gravitational potential energy equation instead?This is the gravitational potential energy equation: E = -G(Mm/R)This is the escape velocity equation: ve = √(2GM/r)Which one are you referring to?
They are related.
Quote from: Yahya on 12/04/2018 10:21:16They are related. If such is the case, then validation of one is validation of the other, yes?
aerospace engineers would launch rockets at speeds much higher than the escape velocity
if they do not have values for the equation on earth how they would compare it on the moon?unless there is an actual test for the equation, do you have evident information for an actual test?
exactly
aerospace engineers would launch rockets at speeds much higher than the escape velocity to avoid the minimum value, giving much higher kinetic energy making the equation of potential energy unnoticeable.
the speed necessary to remain in orbit at a given altitude must also be related to the equations for escape velocity and gravitational potential energy
Ironically, this was completely untrue for the Saturn V. At no point did the rocket actually exceed the Earth's surface escape velocity. Its maximum speed was 10.423 kilometers per second, while Earth's surface escape velocity is 11.2 kilometers per second. Even at the altitude where the Saturn V shut off its engines on the way to the Moon (334.436 kilometers), the escape velocity was 10.905 kilometers per second. If it wasn't for the Moon's gravity helping it out, the rocket would have eventually slowed to a stop and fell back to the Earth.
Quote from: Kryptid on 12/04/2018 20:49:20the speed necessary to remain in orbit at a given altitude must also be related to the equations for escape velocity and gravitational potential energyyou have lack of knowledge to what escape velocity is.Quote from: Kryptid on 12/04/2018 20:49:20Ironically, this was completely untrue for the Saturn V. At no point did the rocket actually exceed the Earth's surface escape velocity. Its maximum speed was 10.423 kilometers per second, while Earth's surface escape velocity is 11.2 kilometers per second. Even at the altitude where the Saturn V shut off its engines on the way to the Moon (334.436 kilometers), the escape velocity was 10.905 kilometers per second. If it wasn't for the Moon's gravity helping it out, the rocket would have eventually slowed to a stop and fell back to the Earth.I'm not sure about the numbers , but you are answering yourself. while the orbit would be an ellipse close to a parabola , you should also take in consideration how close the moon to earth is.
you have lack of knowledge to what escape velocity is.
I'm not sure about the numbers , but you are answering yourself. while the orbit would be an ellipse close to a parabola , you should also take in consideration how close the moon to earth is.
Quote from: Yahya on 13/04/2018 07:50:23Quote from: Kryptid on 12/04/2018 20:49:20the speed necessary to remain in orbit at a given altitude must also be related to the equations for escape velocity and gravitational potential energyyou have lack of knowledge to what escape velocity is.Quote from: Kryptid on 12/04/2018 20:49:20Ironically, this was completely untrue for the Saturn V. At no point did the rocket actually exceed the Earth's surface escape velocity. Its maximum speed was 10.423 kilometers per second, while Earth's surface escape velocity is 11.2 kilometers per second. Even at the altitude where the Saturn V shut off its engines on the way to the Moon (334.436 kilometers), the escape velocity was 10.905 kilometers per second. If it wasn't for the Moon's gravity helping it out, the rocket would have eventually slowed to a stop and fell back to the Earth.I'm not sure about the numbers , but you are answering yourself. while the orbit would be an ellipse close to a parabola , you should also take in consideration how close the moon to earth is.It is not an escape velocity, it is an escape force which needs very little velocity with a set of ladders.
I'm not sure about the numbers
Why are you even trying to say that everyone in the world except you is wrong?
It doesn't matter because it refutes your claim that rockets move much faster than Earth's escape velocity. The Space Shuttle traveled even slower than the Saturn V, at about 7.74 kilometers per second.