Three Questions on Gravity

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Three Questions on Gravity
« on: September 02, 2015, 06:11:57 AM »
This is a simple little idea that's always bothered me. It may just be a misunderstanding on my part, but if accurate it is quite a severe blow to RET.
There are three questions: but first, we just need two to be answered.

  • What value (approximately) does the gravitational constant of Earth take (including units)?
  • What kind of thing do those units refer to?

(To clarify the second question, if the units were, say, kg/ms2 then that would refer to a pressure).
Here for the scientific development of a Flat Earth model. Happy to be proven wrong, as I hope you are too.

Re: Three Questions on Gravity
« Reply #1 on: September 02, 2015, 06:36:47 AM »
Actually, the FAQ of this site uses the same number and units. The FAQ says that the earth is a flat disc accelerating upwards at 9.8 m/s^2.

Those are the units btw, meters per second squared.

*

sircool

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Re: Three Questions on Gravity
« Reply #2 on: September 02, 2015, 06:37:24 AM »
If i understood you Q, here is my answer. Im not a scientist, but an engineering student, so i am very familiar with newtonian phyics.

Earth's gravitational constant g=9.81 N/kg that's newton/kilograms (force/weight) it's not so much a constant as it is an average value measured different places. Trondheim in Norway, where I live, we have a stronger gravity about 9,82. That's because of the oval shape of earth. Because Trondheim is close to the arctic circle and rotation makes the planet wider across the equator, we have a shorter way to the center of mass. + we rotate slower around the poles therefor centripetal acceleration is less

1 newton i think is a kilogram*meter/second^2

This means 1g is 9,81 m/s^2 and that's why we accelerate when we fall

« Last Edit: September 02, 2015, 10:06:28 AM by sircool »
If it's flat, that would be very interesting for science

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Master_Evar

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Re: Three Questions on Gravity
« Reply #3 on: September 02, 2015, 07:57:12 AM »
This is a simple little idea that's always bothered me. It may just be a misunderstanding on my part, but if accurate it is quite a severe blow to RET.
There are three questions: but first, we just need two to be answered.

  • What value (approximately) does the gravitational constant of Earth take (including units)?
  • What kind of thing do those units refer to?

(To clarify the second question, if the units were, say, kg/ms2 then that would refer to a pressure).

1.

Gravity is not constant, it varies ever so slightly depending on you position on earth. Generally it is 9.81 or 9.82 m/s^2. This means that we accelerate downwards at 9.81 (the most general value of gravity) m/s^2.

2.

As I said in answer 1, gravity is an acceleration. The force on an object depends on the gravitational acceleration and it's mass, F=m*g (F is force in Newtons, m is mass in kg and g is gravitational acceleration in m/s^2). Regardless of object size or mass they are always experiencing the exact same gravitational acceleration. Some objects may fall slower because of air resistance or float because of buoyancy.
9.81 m/s^2 means that your velocity increases by 9.81m/s every second.
« Last Edit: September 02, 2015, 08:00:46 AM by Master_Evar »
Math is the language of the universe.

The inability to explain something is not proof of something else.

We don't speak for reality - we only observe it. An observation can have any cause, but it is still no more than just an observation.

When in doubt; sources!

Re: Three Questions on Gravity
« Reply #4 on: September 02, 2015, 08:37:35 AM »
but if accurate it is quite a severe blow to RET.
How does your feigned-confusion represent a severe blow to RET???  The earth is still flat whether you understand it or not.  Regardless, I will pretend you are serious just for the sake of naive readers who are genuinely interested. 

If you think of "gravity" as if it was simply magnetism, your life beyond a vegetative state can still make perfect sense.  The planet earth is a great big torsional magnet with the North Pole at the center. 

Re: Three Questions on Gravity
« Reply #5 on: September 02, 2015, 09:03:09 AM »
How does your feigned-confusion represent a severe blow to RET???  The earth is still flat whether you understand it or not.  Regardless, I will pretend you are serious just for the sake of naive readers who are genuinely interested. 
I am aware of what gravity is. As you may have noticed, there are only two questions in the main post, while the title promises three: the third is the main question, but it requires framework to be asked.
If you would converse without abuse, then we may be able to have an interesting discussion. Currently, I am just confirming what I know about your model. I am just trying to talk, if you default to insults then maybe this forum isn't the place for you.

I'm curious why you need to specify that the Earth is flat whether I understand it or not, given that I did explicitly say I oppose Round Earth Theory in my main post. Was that a typo, or did you misunderstand? Your post history seems to imply that you are, like me, a Flat Earther. Even so, if you get annoyed so easily that you must hurl abuse, you might want to consider taking a break.

To everyone now,
So, to confirm, it is agreed that gravity is an acceleration at approximately 9.81 metres per second per second?
Here for the scientific development of a Flat Earth model. Happy to be proven wrong, as I hope you are too.

?

Master_Evar

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Re: Three Questions on Gravity
« Reply #6 on: September 02, 2015, 09:18:34 AM »
How does your feigned-confusion represent a severe blow to RET???  The earth is still flat whether you understand it or not.  Regardless, I will pretend you are serious just for the sake of naive readers who are genuinely interested. 
I am aware of what gravity is. As you may have noticed, there are only two questions in the main post, while the title promises three: the third is the main question, but it requires framework to be asked.
If you would converse without abuse, then we may be able to have an interesting discussion. Currently, I am just confirming what I know about your model. I am just trying to talk, if you default to insults then maybe this forum isn't the place for you.

I'm curious why you need to specify that the Earth is flat whether I understand it or not, given that I did explicitly say I oppose Round Earth Theory in my main post. Was that a typo, or did you misunderstand? Your post history seems to imply that you are, like me, a Flat Earther. Even so, if you get annoyed so easily that you must hurl abuse, you might want to consider taking a break.

To everyone now,
So, to confirm, it is agreed that gravity is an acceleration at approximately 9.81 metres per second per second?

At the equator at sea level, yes.
Math is the language of the universe.

The inability to explain something is not proof of something else.

We don't speak for reality - we only observe it. An observation can have any cause, but it is still no more than just an observation.

When in doubt; sources!

*

sircool

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Re: Three Questions on Gravity
« Reply #7 on: September 02, 2015, 09:27:26 AM »
To everyone now,
So, to confirm, it is agreed that gravity is an acceleration at approximately 9.81 metres per second per second?
[/quote]

well, that' an unsatisfying answer to a rather complex subject. it's more like a phenomenon created by a large mass that distorts/curves spacetime, and makes you fall to the center of mass by the rate of 9.8 m/s^2
« Last Edit: September 02, 2015, 09:32:22 AM by sircool »
If it's flat, that would be very interesting for science

*

sokarul

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Re: Three Questions on Gravity
« Reply #8 on: September 02, 2015, 09:29:23 AM »
The actual gravitational constant (G) is

6.67410−11 N⋅m2/kg2
and is used in F = G ((m1xm2)/r2 )
ANNIHILATOR OF  SHIFTER

It's no slur if it's fact.

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Serulian

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Re: Three Questions on Gravity
« Reply #9 on: September 02, 2015, 09:54:48 AM »
How does your feigned-confusion represent a severe blow to RET???  The earth is still flat whether you understand it or not.  Regardless, I will pretend you are serious just for the sake of naive readers who are genuinely interested. 
I am aware of what gravity is. As you may have noticed, there are only two questions in the main post, while the title promises three: the third is the main question, but it requires framework to be asked.
If you would converse without abuse, then we may be able to have an interesting discussion. Currently, I am just confirming what I know about your model. I am just trying to talk, if you default to insults then maybe this forum isn't the place for you.

I'm curious why you need to specify that the Earth is flat whether I understand it or not, given that I did explicitly say I oppose Round Earth Theory in my main post. Was that a typo, or did you misunderstand? Your post history seems to imply that you are, like me, a Flat Earther. Even so, if you get annoyed so easily that you must hurl abuse, you might want to consider taking a break.

To everyone now,
So, to confirm, it is agreed that gravity is an acceleration at approximately 9.81 metres per second per second?

   I do not think there is a point to try and measure what you would call gravity, and even supporters of the theory claim it changes wherever you are anyway.

I also do not believe the Earth is accelerating upwards for the record.

Re: Three Questions on Gravity
« Reply #10 on: September 02, 2015, 10:07:09 AM »
I am aware of what gravity is. As you may have noticed, there are only two questions in the main post, while the title promises three: the third is the main question, but it requires framework to be asked.
You are trolling because your 2 questions are by their very essence arbitrary.  The flatness of the earth will not change no matter what arbitrary units of measurement mankind chooses nor is it a function of the arbitrary measurement. 

9.8 whatevers could have been 9.7 or 9.9 as far as the flatness of the earth is concerned. 
If your Big 3rd Main Question hinges on such arbitrariness, then I am asking WHY IS THAT SO????

To everyone now,
So, to confirm, it is agreed that gravity is an acceleration at approximately 9.81 metres per second per second?
No, it is not agreed but what difference, at this point, does it make?!? 
Why do you need such agreement?





but if accurate it is quite a severe blow to RET.
How does your feigned-confusion represent a severe blow to RET??? 

Re: Three Questions on Gravity
« Reply #11 on: September 02, 2015, 10:27:23 AM »
Charming Anarchist, I am not addressing you. I'm not even sure why you felt the need to intervene, I am clearly addressing Round Earthers specifically.

Generally now,
I'll admit that I should have specified my situation. I am talking about an approximate gauge. To be honest, the specific number does not matter in this context: the key is that g is an acceleration, that is that it is given by the units metres per second per second.
(Sircool, thank you for the addition, but those aspects are not important for now).
I just want to make sure I understand this correctly.
Here for the scientific development of a Flat Earth model. Happy to be proven wrong, as I hope you are too.

?

Master_Evar

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  • Well rounded character
Re: Three Questions on Gravity
« Reply #12 on: September 02, 2015, 10:33:42 AM »
Charming Anarchist, I am not addressing you. I'm not even sure why you felt the need to intervene, I am clearly addressing Round Earthers specifically.

Generally now,
I'll admit that I should have specified my situation. I am talking about an approximate gauge. To be honest, the specific number does not matter in this context: the key is that g is an acceleration, that is that it is given by the units metres per second per second.
(Sircool, thank you for the addition, but those aspects are not important for now).
I just want to make sure I understand this correctly.
You seem to understand it correctly, yes.
Math is the language of the universe.

The inability to explain something is not proof of something else.

We don't speak for reality - we only observe it. An observation can have any cause, but it is still no more than just an observation.

When in doubt; sources!

*

sircool

  • 426
  • flat, round, whatever throats your goat
Re: Three Questions on Gravity
« Reply #13 on: September 02, 2015, 10:47:17 AM »
I am eager to read your third question, I am sure it is a good one, and we will have an interesting discussion and learn someting. Let the games begin!
If it's flat, that would be very interesting for science

*

Pezevenk

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Re: Three Questions on Gravity
« Reply #14 on: September 02, 2015, 10:50:00 AM »
How does your feigned-confusion represent a severe blow to RET???  The earth is still flat whether you understand it or not.  Regardless, I will pretend you are serious just for the sake of naive readers who are genuinely interested. 
I am aware of what gravity is. As you may have noticed, there are only two questions in the main post, while the title promises three: the third is the main question, but it requires framework to be asked.
If you would converse without abuse, then we may be able to have an interesting discussion. Currently, I am just confirming what I know about your model. I am just trying to talk, if you default to insults then maybe this forum isn't the place for you.

I'm curious why you need to specify that the Earth is flat whether I understand it or not, given that I did explicitly say I oppose Round Earth Theory in my main post. Was that a typo, or did you misunderstand? Your post history seems to imply that you are, like me, a Flat Earther. Even so, if you get annoyed so easily that you must hurl abuse, you might want to consider taking a break.

To everyone now,
So, to confirm, it is agreed that gravity is an acceleration at approximately 9.81 metres per second per second?

   I do not think there is a point to try and measure what you would call gravity, and even supporters of the theory claim it changes wherever you are anyway.

I also do not believe the Earth is accelerating upwards for the record.

I see some confusion here... Newton's theory of universal gravitation actually PREDICTS that gravity would change wherever you are, but only very slightly.
Member of the BOTD for Anti Fascism and Racism

It is not a scientific fact, it is a scientific fuck!
-Intikam

Read a bit psicology and stick your imo to where it comes from
-Intikam (again)

Re: Three Questions on Gravity
« Reply #15 on: September 02, 2015, 11:14:18 AM »
3. Why does gravity only accelerate things in freefall?

If gravity is, as we've agreed upon, an acceleration, it seems that it should always be acting as an acceleration would: that is, increasing. If you drop something, it moves faster (until it reaches terminal velocity), which we term acceleration due to gravity. So gravity is an acceleration, as can be easily verified, and as we can agree on by the units.

If we examine something on the ground, however, there is no such behavior. Certainly, the obvious answer is to say that whatever the objects rests upon is resisting the force: however, this doesn't make sense if you think about it.
If you take a car and press it against a wall, moving at a slow, constant speed will get you nowhere. If you accelerate that car however, you will quickly find that the damage done will mount up: the stationary behavior of a constant speed is what we observe when something is at rest, rather than the destruction of a constant acceleration.
While gravity may be caused by the bending of spacetime, the fact is this manifests as an acceleration: which is not what we observe for anything not in freefall at the time.
Here for the scientific development of a Flat Earth model. Happy to be proven wrong, as I hope you are too.

*

sokarul

  • 19303
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Re: Three Questions on Gravity
« Reply #16 on: September 02, 2015, 11:18:16 AM »
Gravity can and does accelerate object on the ground. You yourself are undergoing acceleration right now. A simple spring force gauge will show this.
ANNIHILATOR OF  SHIFTER

It's no slur if it's fact.

Re: Three Questions on Gravity
« Reply #17 on: September 02, 2015, 11:27:07 AM »
Gravity can and does accelerate object on the ground. You yourself are undergoing acceleration right now. A simple spring force gauge will show this.

Such gauges were designed with the expectation that it is acceleration acting: if the underlying science is flawed, the results would be as well.
I have explained what I view as the problems with this idea. Please do me the courtesy of responding to them, rather than simply rejecting. I am here for scientific discussion. Acceleration builds up, by definition: its influence would be as I explained. This is not what we observe in any situation on the Earth's surface.
Here for the scientific development of a Flat Earth model. Happy to be proven wrong, as I hope you are too.

*

sokarul

  • 19303
  • Extra Racist
Re: Three Questions on Gravity
« Reply #18 on: September 02, 2015, 11:48:32 AM »
Gravity can and does accelerate object on the ground. You yourself are undergoing acceleration right now. A simple spring force gauge will show this.

Such gauges were designed with the expectation that it is acceleration acting: if the underlying science is flawed, the results would be as well.
I have explained what I view as the problems with this idea. Please do me the courtesy of responding to them, rather than simply rejecting. I am here for scientific discussion. Acceleration builds up, by definition: its influence would be as I explained. This is not what we observe in any situation on the Earth's surface.
Instead of getting stuck by your incompetence, try to actually think. Gravity is above classical physics.
ANNIHILATOR OF  SHIFTER

It's no slur if it's fact.

Re: Three Questions on Gravity
« Reply #19 on: September 02, 2015, 11:56:35 AM »
Instead of getting stuck by your incompetence, try to actually think. Gravity is above classical physics.

Please try to refrain from the abuse. I have explained a specific problem. If all you are going to offer is a special exemption for gravity (when the details of gravity alone are irrelevant: the acceleration is all that matters) then at least explain how this 'above classical physics' applies in this case.

If you don't know the answer, that's fine: that doesn't prove the shape of the Earth one way or another, it just proves you're not omniscient, which everyone knows. If that's the case, just say "Good question," or don't post, rather than insulting or ignoring the question posed.
Here for the scientific development of a Flat Earth model. Happy to be proven wrong, as I hope you are too.

?

Master_Evar

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Re: Three Questions on Gravity
« Reply #20 on: September 02, 2015, 11:59:16 AM »
3. Why does gravity only accelerate things in freefall?

If gravity is, as we've agreed upon, an acceleration, it seems that it should always be acting as an acceleration would: that is, increasing. If you drop something, it moves faster (until it reaches terminal velocity), which we term acceleration due to gravity. So gravity is an acceleration, as can be easily verified, and as we can agree on by the units.

If we examine something on the ground, however, there is no such behavior. Certainly, the obvious answer is to say that whatever the objects rests upon is resisting the force: however, this doesn't make sense if you think about it.
If you take a car and press it against a wall, moving at a slow, constant speed will get you nowhere. If you accelerate that car however, you will quickly find that the damage done will mount up: the stationary behavior of a constant speed is what we observe when something is at rest, rather than the destruction of a constant acceleration.
While gravity may be caused by the bending of spacetime, the fact is this manifests as an acceleration: which is not what we observe for anything not in freefall at the time.

When we accelerate down against the ground, we exert a force on it. The ground then exerts the same force back on us, and that force turns into an equal opposite counter-acceleration. In that car example, it depends on the wall. If it is a roughly 12cm thick insulated wooden wall, and you carefully drive a car up to it so it connects and then try to accelerate, it might eventually give away. But then we have to check if the wall could have handled the weight of the car as well. The same damage that was done by accelerating against the wall using the car engine might be equal to the damage done by letting the car stand on a horizontally placed version of that wall, so that gravity breaks the wall (We also have to take surface area into account for this). But if you put a car up against a thick concrete wall, then no matter how high your acceleration is you are not going to bring that wall down. And putting that wall horizontally and driving the car on top will not bring it down either. So objects on the ground are being accelerated, but the ground itself is resisting with an equal force.
Math is the language of the universe.

The inability to explain something is not proof of something else.

We don't speak for reality - we only observe it. An observation can have any cause, but it is still no more than just an observation.

When in doubt; sources!

*

sircool

  • 426
  • flat, round, whatever throats your goat
Re: Three Questions on Gravity
« Reply #21 on: September 02, 2015, 12:34:58 PM »
Perhaps you should try a different approach. Let me advise you to construct an experiment. it's rather easy and you only need four objects. A table, a book, a ball, and time measuring device (a simple clock will do)

1. Stack the book under one side of your table, actually its better with two books. The goal is to make a tilted plane.

2. make sure the table is as clean as possible to reduce friction.

3. Drop the ball from the highest point and watch the path of the ball, if the ball rolls straight your books don't need any adjustments.

4. Find something to mark half the table length, a post-it note will do. anything will do really :)

5. Now this is the crutial part: Use your clock to measure the time the ball takes from the top and half the table length. Stop the ball when its half way.

6. This is the tricky part: Take the ball, drop it again, but this time I want you to measure only the time after the ball pases middle marking and stop it when it rolls of the table. You should write down and call your data t1 and t2.

The experiment is done and we can examine the results. I predict t1 is not equal to t2, this must mean the ball's velocity has canged. Acceleration is simply the change of velocity over time.

I will also predict that t1>t2. if so, it can only mean that the acceleration is positive.

We can all agree that the ball is in contact with the table throughout the entire experiment, but I suspect acceleration still occurs.
« Last Edit: September 02, 2015, 01:02:24 PM by sircool »
If it's flat, that would be very interesting for science

*

Pezevenk

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Re: Three Questions on Gravity
« Reply #22 on: September 02, 2015, 12:49:21 PM »
Gravity can and does accelerate object on the ground. You yourself are undergoing acceleration right now. A simple spring force gauge will show this.

Such gauges were designed with the expectation that it is acceleration acting: if the underlying science is flawed, the results would be as well.
I have explained what I view as the problems with this idea. Please do me the courtesy of responding to them, rather than simply rejecting. I am here for scientific discussion. Acceleration builds up, by definition: its influence would be as I explained. This is not what we observe in any situation on the Earth's surface.

No no no. You are a bit confused. What acceleration does is essentially "add" to your velocity by a specific amount in a given amount of time. An acceleration of 9.8m/s^2 means that every second, you gain 9.8 meters per second in velocity. The problem is though that the floor beneath you is also pushing you upwards, so your gain in velocity is 0. Nothing "builds up". Right now, you are accelerating towards the ground, while the ground accelerates you upwards. If you didn't accelerate, you would feel like you do when you are in a rollercoaster falling, completely weightless. In order to understand how acceleration works, go on a merry go round and spin really fast. You will feel a force pushing you back, because you are constantly accelerating outwards (in reality, the merry go round is accelerating inwards relative to you, but that is besides the point). Nothing "builds up". You will continue to feel the same for as long as the merry go round spins.
Member of the BOTD for Anti Fascism and Racism

It is not a scientific fact, it is a scientific fuck!
-Intikam

Read a bit psicology and stick your imo to where it comes from
-Intikam (again)

*

Pezevenk

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Re: Three Questions on Gravity
« Reply #23 on: September 02, 2015, 12:58:56 PM »
Perhaps you should try a different approach. Let me advise you to construct an experiment. it's rather easy and you only need four objects. A table, a book, a ball, and time measuring device (a simple clock will do)

1. Stack the book under one side of your table, actually its better with two books. The goal is to make a tilted plane.

2. make sure the table is as clean as possible to reduce friction.

3. Drop the ball from the highest point and watch the path of the ball, if the ball rolls straight your books dont need any adjustments.

4. Find something to mark half the table length, a post-it note will do. anything will do really :)

5. Now this is the crutial part: Use your clock to measure the time the ball takes from the top and half the table length. Stop the ball when its half way.

6. This is the tricky part: Take the ball, drop it again, but this time I want you to measure only the time after the ball pases middle and stop it when it rolls of the table. You should write down and call your data t1 and t2.

The experiment is done and we can examine the results. I predict t1 is not equal to t2, this must mean the ball's velocity has canged. Acceleration is simply the change of velocity.

I will also predict that t1>t2. if so, it can only mean that the acceleration is positive.

We can all agree that the ball is in contact with the table throughout the entire experiment, but acceleration still happens.

Your approach is a bit flawed. It would be better if he made the tilted panel, and stopped the ball and the counter when the ball reached half way down the books, and call it t1. Then he should do the same, only stop the ball (and the counter) when it touches the table, and call it t2. It's obvious that although the ball was not in free fall, it accelerated. Moreover, if it didn't accelerate and had a fixed velocity, t2 should be two times larger than t1. However, since it accelerated, t2 will be slightly less than t1. The only problem is that you should need very accurate measurements, so you would probably need something more than a book.
Member of the BOTD for Anti Fascism and Racism

It is not a scientific fact, it is a scientific fuck!
-Intikam

Read a bit psicology and stick your imo to where it comes from
-Intikam (again)

*

sircool

  • 426
  • flat, round, whatever throats your goat
Re: Three Questions on Gravity
« Reply #24 on: September 02, 2015, 01:08:11 PM »
Perhaps you should try a different approach. Let me advise you to construct an experiment. it's rather easy and you only need four objects. A table, a book, a ball, and time measuring device (a simple clock will do)

1. Stack the book under one side of your table, actually its better with two books. The goal is to make a tilted plane.

2. make sure the table is as clean as possible to reduce friction.

3. Drop the ball from the highest point and watch the path of the ball, if the ball rolls straight your books dont need any adjustments.

4. Find something to mark half the table length, a post-it note will do. anything will do really :)

5. Now this is the crutial part: Use your clock to measure the time the ball takes from the top and half the table length. Stop the ball when its half way.

6. This is the tricky part: Take the ball, drop it again, but this time I want you to measure only the time after the ball pases middle and stop it when it rolls of the table. You should write down and call your data t1 and t2.

The experiment is done and we can examine the results. I predict t1 is not equal to t2, this must mean the ball's velocity has canged. Acceleration is simply the change of velocity.

I will also predict that t1>t2. if so, it can only mean that the acceleration is positive.

We can all agree that the ball is in contact with the table throughout the entire experiment, but acceleration still happens.

Your approach is a bit flawed. It would be better if he made the tilted panel, and stopped the ball and the counter when the ball reached half way down the books, and call it t1. Then he should do the same, only stop the ball (and the counter) when it touches the table, and call it t2. It's obvious that although the ball was not in free fall, it accelerated. Moreover, if it didn't accelerate and had a fixed velocity, t2 should be two times larger than t1. However, since it accelerated, t2 will be slightly less than t1. The only problem is that you should need very accurate measurements, so you would probably need something more than a book.

I agree. The books go under the table legs, the angle should be as small as posible. Then time will be more accurate. Setting up a video camera to record the experiment will be better. If you measure the length of the table, apply some basic trigonometry you will acutally be able to measure earth's gravity acceleration to a near estimate. Of course air resistance will create uncertanty.
« Last Edit: September 02, 2015, 01:15:10 PM by sircool »
If it's flat, that would be very interesting for science

*

Pezevenk

  • 15363
  • Militant aporfyrodrakonist
Re: Three Questions on Gravity
« Reply #25 on: September 02, 2015, 01:25:05 PM »
Perhaps you should try a different approach. Let me advise you to construct an experiment. it's rather easy and you only need four objects. A table, a book, a ball, and time measuring device (a simple clock will do)

1. Stack the book under one side of your table, actually its better with two books. The goal is to make a tilted plane.

2. make sure the table is as clean as possible to reduce friction.

3. Drop the ball from the highest point and watch the path of the ball, if the ball rolls straight your books dont need any adjustments.

4. Find something to mark half the table length, a post-it note will do. anything will do really :)

5. Now this is the crutial part: Use your clock to measure the time the ball takes from the top and half the table length. Stop the ball when its half way.

6. This is the tricky part: Take the ball, drop it again, but this time I want you to measure only the time after the ball pases middle and stop it when it rolls of the table. You should write down and call your data t1 and t2.

The experiment is done and we can examine the results. I predict t1 is not equal to t2, this must mean the ball's velocity has canged. Acceleration is simply the change of velocity.

I will also predict that t1>t2. if so, it can only mean that the acceleration is positive.

We can all agree that the ball is in contact with the table throughout the entire experiment, but acceleration still happens.

Your approach is a bit flawed. It would be better if he made the tilted panel, and stopped the ball and the counter when the ball reached half way down the books, and call it t1. Then he should do the same, only stop the ball (and the counter) when it touches the table, and call it t2. It's obvious that although the ball was not in free fall, it accelerated. Moreover, if it didn't accelerate and had a fixed velocity, t2 should be two times larger than t1. However, since it accelerated, t2 will be slightly less than t1. The only problem is that you should need very accurate measurements, so you would probably need something more than a book.

I agree. The books go under the table legs, the angle should be as small as posible. Then time will be more accurate.

Yeah, that should work out well!
Member of the BOTD for Anti Fascism and Racism

It is not a scientific fact, it is a scientific fuck!
-Intikam

Read a bit psicology and stick your imo to where it comes from
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sokarul

  • 19303
  • Extra Racist
Re: Three Questions on Gravity
« Reply #26 on: September 02, 2015, 01:31:17 PM »
Instead of getting stuck by your incompetence, try to actually think. Gravity is above classical physics.

Please try to refrain from the abuse. I have explained a specific problem. If all you are going to offer is a special exemption for gravity (when the details of gravity alone are irrelevant: the acceleration is all that matters) then at least explain how this 'above classical physics' applies in this case.

If you don't know the answer, that's fine: that doesn't prove the shape of the Earth one way or another, it just proves you're not omniscient, which everyone knows. If that's the case, just say "Good question," or don't post, rather than insulting or ignoring the question posed.
I have a problem with alts.

You asked why gravity can't accelerate objects not in freefall. I explained how it does and a simple way to see it. You dismissed my example because you believe it's wrong. Not because you have evidence stating it's wrong.

Do you feel a force from sitting in your chair? Yes. Does force equal mass times acceleration? Yes. Do you have mass? Yes. So if there is a force and mass, there is acceleration. This is how simple spring force gauges work. You can find the acceleration if you know the spring constant.

So if you are going to keep dismissing ideas, you better bring a reason why. Please note, "I believe" is not one of them.
ANNIHILATOR OF  SHIFTER

It's no slur if it's fact.

Re: Three Questions on Gravity
« Reply #27 on: September 02, 2015, 01:40:57 PM »
Thank you all for the comments.

Quote
But if you put a car up against a thick concrete wall, then no matter how high your acceleration is you are not going to bring that wall down. And putting that wall horizontally and driving the car on top will not bring it down either.
Very true, but the accelerating car would still be damaged. One might be able to resist, but with constant acceleration the other would give way.

Quote
We can all agree that the ball is in contact with the table throughout the entire experiment, but I suspect acceleration still occurs.
True, but only because there is still room to fall. Maybe not freefall, but there is certainly still falling.

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No no no. You are a bit confused. What acceleration does is essentially "add" to your velocity by a specific amount in a given amount of time. An acceleration of 9.8m/s^2 means that every second, you gain 9.8 meters per second in velocity. The problem is though that the floor beneath you is also pushing you upwards, so your gain in velocity is 0. Nothing "builds up". Right now, you are accelerating towards the ground, while the ground accelerates you upwards.
I may be confused, but you have to admit this doesn't quite ring true. Acceleration may be added even without motion: see my car analogy.

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You asked why gravity can't accelerate objects not in freefall. I explained how it does and a simple way to see it. You dismissed my example because you believe it's wrong. Not because you have evidence stating it's wrong.
You provided what you believe is justification for gravity as acceleration without addressing my complaint. My complaint still serves as evidence. If I am asking for clarification of why A does not disprove B, and what you offer is possible evidence for B, and not a contradiction or clarification of A, you have not answered my question. I am asking about A, not B.

Quote
So if you are going to keep dismissing ideas, you better bring a reason why
I have. Everyone else in this thread seems to understand this. What you have offered are insults, nothing more. (And whose alt do you believe I am, pray tell?)
Further, you are using a force gauge on an object that would be falling. If that object rests on a surface, you would measure nothing (except possibly the strength required to lift said object). The force gauge remains irrelevant to the case I am asking about.

I am trying to be level here. I'm here to engage in scientific discussion, not trolling matches. If you are not going to answer my question, which I believe I have expressed clearly (as everyone else appears to understand it), and you are only going to keep insulting, please do not post in this thread.
Here for the scientific development of a Flat Earth model. Happy to be proven wrong, as I hope you are too.

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Pezevenk

  • 15363
  • Militant aporfyrodrakonist
Re: Three Questions on Gravity
« Reply #28 on: September 02, 2015, 02:11:05 PM »
Thank you all for the comments.

Quote
But if you put a car up against a thick concrete wall, then no matter how high your acceleration is you are not going to bring that wall down. And putting that wall horizontally and driving the car on top will not bring it down either.
Very true, but the accelerating car would still be damaged. One might be able to resist, but with constant acceleration the other would give way.

Quote
We can all agree that the ball is in contact with the table throughout the entire experiment, but I suspect acceleration still occurs.
True, but only because there is still room to fall. Maybe not freefall, but there is certainly still falling.

Quote
No no no. You are a bit confused. What acceleration does is essentially "add" to your velocity by a specific amount in a given amount of time. An acceleration of 9.8m/s^2 means that every second, you gain 9.8 meters per second in velocity. The problem is though that the floor beneath you is also pushing you upwards, so your gain in velocity is 0. Nothing "builds up". Right now, you are accelerating towards the ground, while the ground accelerates you upwards.
I may be confused, but you have to admit this doesn't quite ring true. Acceleration may be added even without motion: see my car analogy.

Quote
You asked why gravity can't accelerate objects not in freefall. I explained how it does and a simple way to see it. You dismissed my example because you believe it's wrong. Not because you have evidence stating it's wrong.
You provided what you believe is justification for gravity as acceleration without addressing my complaint. My complaint still serves as evidence. If I am asking for clarification of why A does not disprove B, and what you offer is possible evidence for B, and not a contradiction or clarification of A, you have not answered my question. I am asking about A, not B.

Quote
So if you are going to keep dismissing ideas, you better bring a reason why
I have. Everyone else in this thread seems to understand this. What you have offered are insults, nothing more. (And whose alt do you believe I am, pray tell?)
Further, you are using a force gauge on an object that would be falling. If that object rests on a surface, you would measure nothing (except possibly the strength required to lift said object). The force gauge remains irrelevant to the case I am asking about.

I am trying to be level here. I'm here to engage in scientific discussion, not trolling matches. If you are not going to answer my question, which I believe I have expressed clearly (as everyone else appears to understand it), and you are only going to keep insulting, please do not post in this thread.

What makes you think that if you try to balance a car on its nose against a concrete floor, it won't be damaged due to the acceleration of gravity?  ;)

"True, but only because there is still room to fall. Maybe not freefall, but there is certainly still falling."

And you are still falling when you're sitting down, but the floor constantly halts your fall.

"Acceleration may be added even without motion: see my car analogy."

It's a flawed analogy. A better would be if you used magnets. Magnets accelerate objects the same thing gravity does. Acceleration doesn't "add up". Acceleration is merely the notion of velocity increasing over time, due to a force. If the velocity is constantly being zeroed by equal and opposite force being exerted from the ground, there is no change in velocity, as the ground accelerates you upwards the same amount that the gravity accelerates you downwards. The force is still applied to you though. The acceleration doesn't stop, but there is also acceleration to the opposite direction by the ground, so your velocity doesn't change.
Member of the BOTD for Anti Fascism and Racism

It is not a scientific fact, it is a scientific fuck!
-Intikam

Read a bit psicology and stick your imo to where it comes from
-Intikam (again)

Re: Three Questions on Gravity
« Reply #29 on: September 02, 2015, 02:24:00 PM »
What makes you think that if you try to balance a car on its nose against a concrete floor, it won't be damaged due to the acceleration of gravity?  ;)
That would be the force of gravity acting on a falling engine. That's an important distinction to make though, thank you: solid objects are different to objects that are composed of multiple parts. Solid objects do make my point far clearer, while if multiple parts exist, the movement of something falling on the inside may give the appearance of damage to the outside, when the harm was primarily internal .

Quote
It's a flawed analogy. A better would be if you used magnets. Magnets accelerate objects the same thing gravity does. Acceleration doesn't "add up". Acceleration is merely the notion of velocity increasing over time, due to a force. If the velocity is constantly being zeroed by equal and opposite force being exerted from the ground, there is no change in velocity, as the ground accelerates you upwards the same amount that the gravity accelerates you downwards. The force is still applied to you though. The acceleration doesn't stop, but there is also acceleration to the opposite direction by the ground, so your velocity doesn't change.
All analogies are flawed. Magnets do give an interesting query, but ultimately magnetic fields are very different to gravity. A better analogy is not one which supports the view you want to make, but rather the one that best describes the situation: the car gives a controllable situation where velocity and acceleration may be measured, and a wall may serve as our ground. If it accelerates at a constant rate while touching the wall, it will be damaged: if it moves at a constant speed, it exists as we do.
What do you mean by the ground accelerating? The ground is, in the frame of reference we're concerned with, perfectly stationary.
Here for the scientific development of a Flat Earth model. Happy to be proven wrong, as I hope you are too.