Gravitation between the Moon and the Earth: physics project

AI Thread Summary
The discussion focuses on a physics project analyzing the gravitational interaction between the Moon and Earth, emphasizing the need to calculate the Moon's acceleration and motion using Newton's laws and gravitational equations. The participant plans to use Excel for integration and graphing but struggles with the changing radius between the two bodies and the implications of fixing one body in place. Concerns arise regarding the assumption that only the Moon is moving, as this could violate conservation of momentum. Suggestions include using angular momentum and considering the Earth as a fixed point to simplify calculations. The final approach involves using Riemann sums for integration and ensuring accurate initial conditions for the Moon's velocity and position.
  • #51
Omg i think its finally working i am so dumb i was changing the acceleration value now i am keeping "a" constant and only changing the ax and ay based on position currently dragging down 1 cell at a time since they all depend on each other
 
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  • #52
ok think i got it
now i have no idea how to graph this data, that's the next challenge

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  • #53
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moon has escaped orbit
 

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  • #54
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  • #55
this is looking good to me, bvu thank you for all the help! i finally got it somewhat working
(the name "position y" is misleading) this is the x and y coordinates plotted
 
  • #56
beautiful :')

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  • #57
In fact it shouldn't come out as a circle with the set of equations and initials we had. Has to do with reduced mass.

A physics complication. There's also a math complication: an issue with simple forward Euler for this kind of problem. But you learned a great deal which is far more important than getting the 'right' result.

Good luck with the test. I hope you did get some kip :rolleyes:
 
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  • #58
BvU said:
In fact it shouldn't come out as a circle with the set of equations and initials we had. Has to do with reduced mass.

A physics complication. There's also a math complication: an issue with simple forward Euler for this kind of problem. But you learned a great deal which is far more important than getting the 'right' result.

Good luck with the test. I hope you did get some kip :rolleyes:
Thank you, i will sleep after this report and study tommorow before the test, already went over the whole practice exam once
 
  • #59
isukatphysics69 said:
now i am keeping "a" constant and only changing the ax and ay based on position
Sorry for the bummer, but that isn't the idea of the exercise.
currently dragging down 1 cell at a time since they all depend on each other
in principle row n only depends on row n-1. That's forward Euler for you, the often self-quoted recipe$$x_n = x_{n-1} + v_{x, n-1} * dt \\y_n = y_{n-1} + v_{y, n-1} * dt \\v_{x, n} = v_{x, n} + a_{x, n-1} * dt \\v_{y, n} = v_{y, n-1} + a_{y, n-1} * dt$$

gotta face the drill now
 
  • #60
BvU said:
Sorry for the bummer, but that isn't the idea of the exercise.
in principle row n only depends on row n-1. That's forward Euler for you, the often self-quoted recipe$$x_n = x_{n-1} + v_{x, n-1} * dt \\y_n = y_{n-1} + v_{y, n-1} * dt \\v_{x, n} = v_{x, n} + a_{x, n-1} * dt \\v_{y, n} = v_{y, n-1} + a_{y, n-1} * dt$$

gotta face the drill now
aw crap what
its not possible at this point, its 4 am and due tommorow
 
  • #61
isukatphysics69 said:
aw crap what
its not possible at this point, its 4 am and due tommorow
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  • #62
i am attempting to fix it
 
  • #63
i think i just fixed it, if you come back please let me know
oh my lord i think i may have just fixed it
 
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  • #64
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  • #65
Graphs are updated and still looking good, not much of a change in the graphs as i go lower the acceleration is decreasing
 
  • #66
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  • #67
I think this is what i have to go with regardless. i gave it my best shot now have to move on and will read feedback if given from prof
 
  • #68
this is screwed
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  • #69
Kudos for your tenacity ! Hope the test went well...

I mentioned you in a related thread . A lot of good reading in the pdf link in post #5.

There also is a recent earth-moon thread here:
CrosisBH said:
So I was messing with VPython, trying to create an Earth-Moon System. I got the actual gravity to work, and can create some nice ellipical orbits. However I run into trouble trying to make the actual (almost) circular orbit of the moon.
...
 
  • #70
Definitely failed that final exam but my test average this semester was 84 over 6 test so I think I will pass the course. Very disappointed in self but how on Earth ani supposed to pass a final that has 2/6 questions that we covered last week. So I answers 3/ 6 questions and we were supposed to answer 4/6 to have a chance at full credit plus this project lack of sleep and food was a recipe for disaster plus I'm just a complete moron but whatever I failed sometimes you fail
 
  • #71
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  • #72
isukatphysics69 said:
Definitely failed that final exam but my test average this semester was 84 over 6 test so I think I will pass the course. Very disappointed in self but how on Earth ani supposed to pass a final that has 2/6 questions that we covered last week. So I answers 3/ 6 questions and we were supposed to answer 4/6 to have a chance at full credit plus this project lack of sleep and food was a recipe for disaster plus I'm just a complete moron but whatever I failed sometimes you fail
Sure, and the world is a bad place etcetera
You're entitled to a bit of disappointment, not to a lamentation like this and self depreciation. Consider it a learning experience: planning, sleep, food, whatever is imoporant too and can only be ignored at a price. You come out of this better than you were. Cheer up.
Find a real shoulder if necessary. PF doesn't provide effectively in such matters :smile:
 
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  • #73
BvU said:
Sure, and the world is a bad place etcetera
You're entitled to a bit of disappointment, not to a lamentation like this and self depreciation. Consider it a learning experience: planning, sleep, food, whatever is imoporant too and can only be ignored at a price. You come out of this better than you were. Cheer up.
Find a real shoulder if necessary. PF doesn't provide effectively in such matters :smile:
Alright man thank you, I'm sure i will be back posting 10 threads per week again in the fall for physics 2. Have a good summer
BvU said:
Sure, and the world is a bad place etcetera
You're entitled to a bit of disappointment, not to a lamentation like this and self depreciation. Consider it a learning experience: planning, sleep, food, whatever is imoporant too and can only be ignored at a price. You come out of this better than you were. Cheer up.
Find a real shoulder if necessary. PF doesn't provide effectively in such matters :smile:
thank you for all the help, I'm sure I will be back for calculus 3 in a few weeks. Take care :)
 
  • #74
Good show ! See you !
 
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