Debunking the idea the earth accelerates upward

Oh and you dont need to worry about signs here do you.

This is basically 2 equations to find the time taken for the earth to move 2 sets of 4 meters.

Everything is positive for both

No. Up is positive. Down is negative. Or you can reverse them. As long as you are consistent. If I had made everything positive in the first equation, I would have gotten something besides 0.9 seconds.

I don't normally do this, but as a last ditch effort, I am going to try an appeal to authority. I have been studying mathematics for a very long time. I know a lot of mathematics. This is the type of thing I can do in my sleep. Please believe me.

If you still don't believe me, I'll have to let someone else handle it. Time for some sleep.

Quote from: Physicsteacher on August 26, 2016, 01:45:11 AM

Oh and you dont need to worry about signs here do you.

This is basically 2 equations to find the time taken for the earth to move 2 sets of 4 meters.

Everything is positive for both

No. Up is positive. Down is negative. Or you can reverse them. As long as you are consistent. If I had made everything positive in the first equation, I would have gotten something besides 0.9 seconds.

I don't normally do this, but as a last ditch effort, I am going to try an appeal to authority. I have been studying mathematics for a very long time. I know a lot of mathematics. This is the type of thing I can do in my sleep. Please believe me.

If you still don't believe me, I'll have to let someone else handle it. Time for some sleep.

Ok

I believe you when you say your maths is strong...

So, what might be happening is a misinterpretation of my text.

I WILL make that video - but it wont be for at least another 8 hours, and if im busy tonight, make it 36 hours.

...
Secondly, I do believe that round earthers are more intelligent than flat earthers.  Why? Well because the earth isn't flat, all the evidence points to a round earth - so to believe a flat earth, despite that, requires a very low intelligence level.

I wouldn't agree with you.

(That way of thinking doesn't show readiness for understanding / tollerating / guiding different students in class,
and their "reasons of the moment" wether based on slow understanding or on their current emotions.)

Flat Earthers  have strong desire to believe the Earth is flat.
For one reason or another, good or bad.

Ski believes she's doing right thing.
Eric Dubai believes he can deceive the world with bullsh*t and get money by gathering more naive subscribers.
As you can see, two totally different, completely opposite ones.

It has nothing to do with intelligence. Or not much.

It has a lot to do with intelligence. Everyone with an IQ above room temperature and a normal education can easily disprove flat earth by researching for an afternoon.

A vast amount of stupidity is required to seriously believe in a flat earth.

Maths time!



s - displacement: the distance travelled by the object under question.
t - how much time passes in the situation under question
u - initial velocity of the object at starting point
v - velocity at end of time
a - acceleration of the object.

All this has been said already, I just want everything to be contained in one post for easy reading/reference.

So, let's throw a ball up with fixed speed u>0, where we model the Earth's starting velocity to be zero.
How long is it before the Earth's speed is u? In practise, this will be modelled by the top of the ball's arc, before it seems to begin descending.
Well, a=9.8, u=0, v=u, we want to find t.
Use the first SUVAT equation to find t = u/9.8

Now then, at this point, the Earth and the ball are travelling at the same speed, so it will seem as though the ball is stationary in the air. A moment before, it was ascending: a moment after, it's descending.

Unnecessary step, but fun:
The ball is still moving at speed u. As such, we run into Zeno's paradox: by the time the Earth catches up with it, the ball has still had a chance to move on a little further.
Let's look at how long it takes, from our starting point, for the Earth to catch up with the ball.
Using the fact the ball is not accelerating so a=0, we use our value of t and u=u, to note s=u²/9.8. This is how far it travels before the Earth's speed is the same as it.
(The Earth reaches that point in root(2) u^2/9.8 )
But when the Earth reaches that point, the ball's moved on. And when the Earth meets that point, the object's moved on...
An infinite sum clearly isn't the easiest way to solve this, but it easily gives us a way to check:


Let's see what happens when t = 2u/9.8. This is twice the time taken for the ball to reach the apex of its flight. We use the second equation.
The displacement of the ball is s=ut = 2u²/9.8
The displacement of the Earth, using the same equation, is s=0.5at² = 2u²/9.8

They've both travelled the same distance, so the ball would in fact take the same amount of time to ascend as it does to descend.

The Earth's round, and there are a lot of issues with UA, but this isn't one of them. The flaws with your working have already been pointed out.

It has a lot to do with intelligence. Everyone with an IQ above room temperature and a normal education can easily disprove flat earth by researching for an afternoon.

A vast amount of stupidity is required to seriously believe in a flat earth.

Stupidity is not always the explanation.

Emotions influence our lives no less than logic.
In some situations even more.

If you want to communicate with people, you have to understand them.

Maths time!



s - displacement: the distance travelled by the object under question.
t - how much time passes in the situation under question
u - initial velocity of the object at starting point
v - velocity at end of time
a - acceleration of the object.

All this has been said already, I just want everything to be contained in one post for easy reading/reference.

So, let's throw a ball up with fixed speed u>0, where we model the Earth's starting velocity to be zero.
How long is it before the Earth's speed is u? In practise, this will be modelled by the top of the ball's arc, before it seems to begin descending.
Well, a=9.8, u=0, v=u, we want to find t.
Use the first SUVAT equation to find t = u/9.8

Now then, at this point, the Earth and the ball are travelling at the same speed, so it will seem as though the ball is stationary in the air. A moment before, it was ascending: a moment after, it's descending.

Unnecessary step, but fun:
The ball is still moving at speed u. As such, we run into Zeno's paradox: by the time the Earth catches up with it, the ball has still had a chance to move on a little further.
Let's look at how long it takes, from our starting point, for the Earth to catch up with the ball.
Using the fact the ball is not accelerating so a=0, we use our value of t and u=u, to note s=u²/9.8. This is how far it travels before the Earth's speed is the same as it.
(The Earth reaches that point in root(2) u^2/9.8 )
But when the Earth reaches that point, the ball's moved on. And when the Earth meets that point, the object's moved on...
An infinite sum clearly isn't the easiest way to solve this, but it easily gives us a way to check:


Let's see what happens when t = 2u/9.8. This is twice the time taken for the ball to reach the apex of its flight. We use the second equation.
The displacement of the ball is s=ut = 2u²/9.8
The displacement of the Earth, using the same equation, is s=0.5at² = 2u²/9.8

They've both travelled the same distance, so the ball would in fact take the same amount of time to ascend as it does to descend.

The Earth's round, and there are a lot of issues with UA, but this isn't one of them. The flaws with your working have already been pointed out.

No - spectacularly wrong.

The fact that you wrote "how long before the earth reaches U" shows you have no idea about the context of the equations in my posts.

Either a) you didn't or b) you couldn't understand them


wait for the video - it wont be too long

No - spectacularly wrong.

The fact that you wrote "how long before the earth reaches U" shows you have no idea about the context of the equations in my posts.

Either a) you didn't or b) you couldn't understand them


wait for the video - it wont be too long

I wasn't using your method. Mine still makes sense, though. Model things as the Earth beginning at 0 (easy to do by choice of reference frame), and if the Earth accelerates it must eventually reach the speed of the ball u. What's wrong with that?
I understand your posts, as others have pointed out you arbitrarily assumed that there were two values of t when, well, there just aren't. That's how the SUVAT equations work: five values, five constants. The t-value you use at one point in an equation is the same as every other t in that equation.

Now the SUVAT equation we will use is S = UT + 1/2AT SQUARED (I can't do superscript from my phone)

Let's rearrange to get time...?
This gives

T squared = S/(UT +1/2A)

Here S = distance
T = time
A = acceleration
U = initial starting speed of the earth (not ball, which is where you cocked up)


So, how long does it take the earth to travel those first 4m?? In other words, bow long does it take for the ball to go up??

Well according to the equation I gave you in the last post (where U is zero remember)

T squared = 4/(0 + 1/2 9.8 )


This gives a time of......0.81s for T squared

So T = 0.9s

Remember, this is the time taken for the ball to rise

HA HA HA HA !
... Excuse me, but this was just too funny.
More seriously I will stop to make fun of you, and just explain why your math is wrong, IF you accept to read the posts of other and entertain the possibility of being wrong.

In the equation you tried to use ( s = (1/2)*a*tē + u*t ), s, a and u are the displacement, the acceleration and initial velocity of your system. If you want your system to be the ball, so be it. If you want your system to be the earth, that's strange but that's ok. However, you cannot say that it's both.

You said that u=0 and  a = g =9,8, so your system is the earth. So what you have calculated is how much time it takes the earth to travel up by 4 meters. Are you still with me ?

But then you say "Remember, this is the time taken for the ball to rise". Except it's not. There is no rising ball at all in your system.

You did not even care to introduce the initial velocity of the ball, and still you expect it to rise. How ?
Ever try to throw a ball by letting it fall on the ground ?
It does not go up.
At all.

The time you calculated is how much time it takes for the earth to rise of 4 meters. Nothing more.
The idea that the ball will rise for 4 meters and then fall for 4 meters is proved nowhere in your post, nor do you care to explain if you mean distance with the Earth or absolute distance to the non accelerating referential.
Way to assume your result.

I mean, your whole post shows that you are using formulas that you obviously don't understand.
I'm not trying to make an appeal to authority, but have you even finished high school ? I just can't understand anyone with any sort of undergrad background in physics sprouting this nonsense, much less a pysic teacher.

How do you need 8 pages to discuss this? I've read nothing but the first post and feel like it's enough.
Obviously it's wrong; one could not distinguish an upwards accleration from a gravitational field, but there are sooooo many other ways to show that the accleration thing is bullshit.

Again, how can you discuss this 8 pages long?

How do you need 8 pages to discuss this? I've read nothing but the first post and feel like it's enough.
Obviously it's wrong; one could not distinguish an upwards accleration from a gravitational field, but there are sooooo many other ways to show that the accleration thing is bullshit.

Again, how can you discuss this 8 pages long?

The original poster refuse to admit that he's wrong and it's funny.
Also there are some flat earth believers that tried to disucss their own view of UA somewhere in the middle of the thread.

Its not wrong, you just don't get it.

Video is done and is just processing

Quote from: Physicsteacher on August 25, 2016, 09:25:10 PM

Now the SUVAT equation we will use is S = UT + 1/2AT SQUARED (I can't do superscript from my phone)

Let's rearrange to get time...?
This gives

T squared = S/(UT +1/2A)

Here S = distance
T = time
A = acceleration
U = initial starting speed of the earth (not ball, which is where you cocked up)


So, how long does it take the earth to travel those first 4m?? In other words, bow long does it take for the ball to go up??

Well according to the equation I gave you in the last post (where U is zero remember)

T squared = 4/(0 + 1/2 9.8 )


This gives a time of......0.81s for T squared

So T = 0.9s

Remember, this is the time taken for the ball to rise

HA HA HA HA !
... Excuse me, but this was just too funny.
More seriously I will stop to make fun of you, and just explain why your math is wrong, IF you accept to read the posts of other and entertain the possibility of being wrong.

In the equation you tried to use ( s = (1/2)*a*tē + u*t ), s, a and u are the displacement, the acceleration and initial velocity of your system. If you want your system to be the ball, so be it. If you want your system to be the earth, that's strange but that's ok. However, you cannot say that it's both.

You said that u=0 and  a = g =9,8, so your system is the earth. So what you have calculated is how much time it takes the earth to travel up by 4 meters. Are you still with me ?

But then you say "Remember, this is the time taken for the ball to rise". Except it's not. There is no rising ball at all in your system.

You did not even care to introduce the initial velocity of the ball, and still you expect it to rise. How ?
Ever try to throw a ball by letting it fall on the ground ?
It does not go up.
At all.

The time you calculated is how much time it takes for the earth to rise of 4 meters. Nothing more.
The idea that the ball will rise for 4 meters and then fall for 4 meters is proved nowhere in your post, nor do you care to explain if you mean distance with the Earth or absolute distance to the non accelerating referential.
Way to assume your result.

I mean, your whole post shows that you are using formulas that you obviously don't understand.
I'm not trying to make an appeal to authority, but have you even finished high school ? I just can't understand anyone with any sort of undergrad background in physics sprouting this nonsense, much less a pysic teacher.

Just watch the video - how u don't get this is beyond me

Its not wrong, you just don't get it.

Video is done and is just processing

Can you say what part of my working is wrong, then?
Clearly the Earth would reach the speed u of the ball at some point, so that's no objection.

So, when I throw a ball in the air, it takes the same time to go up as it does to come down. This is standard if the earth is not accelerating up.

However, due to the FE belief of acceleration of earth upward the ball would fall in a shorter time than it took to go up - but this doesnt happen.

Now, unless u cant understand the difference/separate acceleration from movement, how do you explain this?

Gravity must exist?

Your claim is false.

Somebody expects some plain math. I'll try to end the argument with that.

Suppose at the moment the ball leaves your hand, the (absolute) velocity of the ball is v1, while the (absolute) velocity of the earth is v0. In order for the ball to be thrown upwards, the following relation must be satisfied: v1 > v0.

According to the FE claims, the earth is accelerating up at the rate of g(=9.8m/s^2).

Let T_up be the time the ball takes to go up. Then
T_up = (v1 - v0) / g

The distance between ball and earth (aka altitude of the ball) at the time of T_up:
H = v1 * T_up - (v0 * T_up + (1/2) * g * T_up^2)
   = (v1 - v0) * T_up - (1/2) * g * T_up^2
   = (1/2) * (v1 - v0)^2 / g
   = (1/2) * g * T_up^2

Let T_down be the time the ball takes to go down. Similarly,
H = v1* T_down + (1/2) * g * T_down^2 - v1 * T_down
   = (1/2) * g * T_down^2

Compare the last two equations, we can easily see that: T_up = T_down.

Right
Let me guess what u will be picky with...

1) My phone autorotated the video, so it appears sideways.  Just put up with it or don't watch it, I'm sure you can lock rotation on your phone to correct it.

2) At one point I say 9.8 x 1.4 is 14, but that's because I was actually multiplying 9.8 by 1.429. If you follow the video u will know why

Now let's see if you numpties can understand conceptual ideas and the proper use of maths. 

I'm going out for an hour.

I'll answer any questions when I'm back

Right
Let me guess what u will be picky with...

1) My phone autorotated the video, so it appears sideways.  Just put up with it or don't watch it, I'm sure you can lock rotation on your phone to correct it.

2) At one point I say 9.8 x 1.4 is 14, but that's because I was actually multiplying 9.8 by 1.429. If you follow the video u will know why

Now let's see if you numpties can understand conceptual ideas and the proper use of maths. 

Your whole problem is that you believe for some reason that S=10 meters in both case - which is an unsubtansiated claim, since you did not define S.
Your calculs show since the Earth travels faster in the second phase, it take less time to rise up 10 meters. Well, duh. We knew that.

Your problem is you do not define S properly.

If S is the distance travelled by the Earth, your calculations are correct but have nothing to do with the ball. Earth travels 10 meters =! ball rise 10 meters.

If S is the distance between the Earth and the ball, you fail to see that the ball is even moving. Nowhere in your calculations do the initial velocity of the ball appear. What you also fail to see is in that theory, when you believe the ball has risen up 10 meters in the air, it has actually risen more than that. Also again ball rising 10 meters up != earth rising 10 meters up.

I touch on thst right at the end of the video.

Watch the very end where I say the movement of the ball compounds this.

Right, back in an hour

Now let's see if you numpties can understand conceptual ideas and the proper use of maths.

I understand it just fine. I defined u to be the (initial) speed of the ball. if it's easier, just treat it as x. It's fair enough as applying SUVAT to the Earth, u=0, so there's little risk of confusion for anyone who more than skims my calculations. I'm just more comfortable using unknowns, it's often clearer what's going on.

You seem to be relying on a flawed intuitive understanding. When you throw a ball, the Earth reaches the ball's speed: this doesn't mean the Earth is halfway to the ball.
You're also calculating the time it takes for the Earth to go 10m (or whatever units you prefer) into the air. That doesn't make sense, unless you're defining that to be the point at which the ball begins to descend/the Earth matches the speed of the ball, but that really doesn't seem to be what you're doing. You're confusing the two objects under discussion; the ball moves 10m into the air (in the reference frame of the Earth), but the Earth moving 10m has no significance. The ball is always going to be moving up with its starting speed (treating air resistance as negligible) so it would in fact be travelling more than 10m. Yes, you said this, but you ignored its relevance. What is the benefit of calculating the time it takes for the Earth to move 10m, when that has no relevance to the distance the ball moves, or the relative velocities of the ball and Earth, or indeed anything that's actually under discussion?

To rewrite my previous calculations with a letter changed as that apparently confused you:
I await to hear what flaw you find.

So, let's throw a ball up with fixed velocity x>0, where we model the Earth's starting velocity to be zero.
How long is it before the Earth's velocity is x? In practise, this will be modelled by the top of the ball's arc, before it seems to begin descending. (It's the point at which the Earth begins to move faster than the ball, so the ball looks like it's falling).
Well, a=9.8, u=0, v=x, we want to find t.
Use the first SUVAT equation v=u+at to find t = x/9.8
Now then, at this point, the Earth and the ball are travelling at the same speed, so it will seem as though the ball is stationary in the air. A moment before, it was ascending: a moment after, it's descending.
Let's see what happens when t = 2u/9.8. This is twice the time taken for the ball to reach the apex of its flight. We use the second equation, your s=ut + 0.5at²
The displacement of the ball (u=x, a=0) is s=ut = 2x²/9.8
The displacement of the Earth (u=0, a=9.8 ), using the same equation, is s=0.5at² = 2x²/9.8

That is, the ball is back to its starting point, and it takes the same time to go up as it does to go down.

Trust me, I understand maths. First class BSc degree, and about a month away from an MSc, and happy to walk you through my dissertation if you've any interest in ratios of eigenvalues of Schrodinger operators. This topic, however, is trivially simple.

I'm going out for an hour.

I'll answer any questions when I'm back

Any questions ?
Ok answer this little quizz then  :

(Please don't use google, just answer from memory or with intuition.)

1) Quantum physics : Of which of the following mathematical or physical facts can one rigorously deduce the Hesienberg principle of incertitude ?

a) Wave functions have no well defined position.
b) Linear operators of a non-trivial linear space do not form a commutative ring.
c) Fourier transformation of real periodic functions yields infinite results (from which stems the necessity of using distributions).
d) Information can not travel faster than the speed of light.
e) It is impossible to measure position of elementary particles without disturbing them by interaction with the measuring equipment.

2) Optics : Why can't you use transmission electronic microscopy in bright field with a thick sample ? Why can you do so with an optic microscope ?

a) Because of shorter wavelength
b) Because of longer wavelength
c) Because of fundamental differences in the interaction with the sample
d) Because of chroma
e) Because of reflected light

3) Thermodynamics : What is the main reason why your coffee get cold faster when there is wind ?

a) Because the winds make your cofee move faster inside your cup.
b) Because of cold wind currents.
c) Because the wind makes the heating air up of your cup go away faster.
d) Because dioxygen reacts with carbon in the cofee.
e) Because winds make your cofee evaporate faster.

4) Statistical physics : What is the difference between bosons and fermions ?

a) They are not made of the same elementary particles.
b) The spin of bosons is of greater value than the spin of fermions.
c) They differ in their potential occupation numbers per elementary state .
d) Fermions interact with matter, bosons pass through it unaffected.
e) Bosons have no mass and can reach higher speed.

5) Electromagnetism : One of this phenomenon or physical law can not be deduced from Maxwell laws. Which one ?

a) Induction.
b) Ohm's law.
c) Capacitor charge.
d) Electro-magnets.
e) Kirchoff current law.

Enjoy ! 

Is this thread still about how we can't reach the speed of light? And people call me silly because I don't believe in dinosaurs. They simultaneously don't believe in relativity while also believing in it - and use it to hold up their untenable and silly view of a globe. All unbeknownst to themselves.

Another victory for flat earth!

Is this thread still about how we can't reach the speed of light? And people call me silly because I don't believe in dinosaurs. They simultaneously don't believe in relativity while also believing in it - and use it to hold up their untenable and silly view of a globe. All unbeknownst to themselves.

Another victory for flat earth!

It seems to be about how objects fall faster than they rise. Just as wrong, but differently so.
I don't think one silly REer is a victory for FE, otherwise you wouldn't be doing that great either 

Is this thread still about how we can't reach the speed of light? And people call me silly because I don't believe in dinosaurs. They simultaneously don't believe in relativity while also believing in it - and use it to hold up their untenable and silly view of a globe. All unbeknownst to themselves.

Another victory for flat earth!

Yeah, just this once, can we shove the elephant out of the room and just focus on showing that guy why his physic is wrong ?
After that, I promise, we can all return to the pointless debate about the Judeo-Masonico-Islamo-Fascist-Velociraptor conspiracy.

(The elephant being the fact that you crackpots believe the Earth is flat when its obviously a cylindrical shaped hypercube in a 2 dimensional space projected in a 3 dimensional space. Even children know that.)

Quote from: Physicsteacher on August 26, 2016, 08:22:23 AM

Right
Let me guess what u will be picky with...

1) My phone autorotated the video, so it appears sideways.  Just put up with it or don't watch it, I'm sure you can lock rotation on your phone to correct it.

2) At one point I say 9.8 x 1.4 is 14, but that's because I was actually multiplying 9.8 by 1.429. If you follow the video u will know why

Now let's see if you numpties can understand conceptual ideas and the proper use of maths. 

Your whole problem is that you believe for some reason that S=10 meters in both case - which is an unsubtansiated claim, since you did not define S.
Your calculs show since the Earth travels faster in the second phase, it take less time to rise up 10 meters. Well, duh. We knew that.

Your problem is you do not define S properly.

If S is the distance travelled by the Earth, your calculations are correct but have nothing to do with the ball. Earth travels 10 meters =! ball rise 10 meters.

If S is the distance between the Earth and the ball, you fail to see that the ball is even moving. Nowhere in your calculations do the initial velocity of the ball appear. What you also fail to see is in that theory, when you believe the ball has risen up 10 meters in the air, it has actually risen more than that. Also again ball rising 10 meters up != earth rising 10 meters up.

Ok first of all at the end of the video I do mention the moving ball. You didn't watch did you??

The movement of the ball at constant speed (which is what my understanding of UA says is happening), is what we call a "zero error" in the UK.

This means, in relation to my video, that it affects the up time and down time in the same way - and therefore is not relevant to proving the point that it falls faster.

The only way it can take the same time to fall as it does to rise, is if it accelerates in what I called part 2 (when it appears to fall)

I can factor it in for you, all it will do is change the predictions of T as a number. What it won't do is stop the time taken to rise being bigger, which is the point of this thread.

In fact either

 a) give me a speed of the ball relative to the earth and I'll do another video proving it, or

b) do a video with the speed of the ball factored in yourself.

Jane, you seen clueless, so you can try the same

You can't  argue for UA and win against what I am saying

Quote from: ceciestuncompte on August 26, 2016, 08:42:09 AM

Quote from: Physicsteacher on August 26, 2016, 08:22:23 AM

Right
Let me guess what u will be picky with...

1) My phone autorotated the video, so it appears sideways.  Just put up with it or don't watch it, I'm sure you can lock rotation on your phone to correct it.

2) At one point I say 9.8 x 1.4 is 14, but that's because I was actually multiplying 9.8 by 1.429. If you follow the video u will know why

Now let's see if you numpties can understand conceptual ideas and the proper use of maths. 

Your whole problem is that you believe for some reason that S=10 meters in both case - which is an unsubtansiated claim, since you did not define S.
Your calculs show since the Earth travels faster in the second phase, it take less time to rise up 10 meters. Well, duh. We knew that.

Your problem is you do not define S properly.

If S is the distance travelled by the Earth, your calculations are correct but have nothing to do with the ball. Earth travels 10 meters =! ball rise 10 meters.

If S is the distance between the Earth and the ball, you fail to see that the ball is even moving. Nowhere in your calculations do the initial velocity of the ball appear. What you also fail to see is in that theory, when you believe the ball has risen up 10 meters in the air, it has actually risen more than that. Also again ball rising 10 meters up != earth rising 10 meters up.

Ok

The movement of the ball at constant speed (which is what my understanding of UA says is happening), is what we call a "zero error" in the UK.

This means, in relation to my video, that it affects the up time and down time in the same way - and therefore is not relevant to proving the point that it falls faster.

The only way it can take the same time to fall as it does to rise, is if it accelerates in what I called part 2 (when it appears to fall)

I can factor it in for you, all it will do is change the predictions of T as a number. What it won't do is stop the time taken to rise being bigger.

In fact either

 a) give me a speed of the ball relative to the earth and I'll do another video proving it, or

b) do a video with the speed of the ball factored in yourself.

Jane, you seen clueless, so you can try the same

I won't do a video (because I like to keep some form of anonymity), but I will send you a scan of a sheet of schemas and calculs.
If you want to, I can even do a simulation of the movement of the ball using any one simulation software of your choice (or a home made python or scilab program if you insist).

Also it has no bearing on anything whatsoever, but can you or anyone else answer my quizz (some questions are pretty specific so I don't care that much if you're wrong) ? Pretty please ?

Jane, you seen clueless, so you can try the same

I've given you the calculations. Your only issue seemed to be an unclear definition of a variable, which I fixed.

Your method is fundamentally flawed. Asking us to repeat it or repeating it yourself isn't going to fix those flaws. The Earth travelling 10m (or whatever distance you care to define) has no inherent relation to how far the ball travels, the relative speeds of the Earth and the ball... What you're calculating has no relationship to what you're claiming. It's that simple.

If I'm so clueless, then please actually respond to my maths rather than ignoring it. If it's so clueless, it should be easy for you to rebut.
What I do is simple: I find the time needed for the Earth to be travelling at the same speed for the ball (keeping it general. if it makes you happy, set x=4 or z=10 or whatever), I then show at twice that time the ball is back where it started.

So, let's throw a ball up with fixed velocity x>0, where we model the Earth's starting velocity to be zero.
How long is it before the Earth's velocity is x? In practise, this will be modelled by the top of the ball's arc, before it seems to begin descending. (It's the point at which the Earth begins to move faster than the ball, so the ball looks like it's falling).
Well, a=9.8, u=0, v=x, we want to find t.
Use the first SUVAT equation v=u+at to find t = x/9.8
Now then, at this point, the Earth and the ball are travelling at the same speed, so it will seem as though the ball is stationary in the air. A moment before, it was ascending: a moment after, it's descending.
Let's see what happens when t = 2u/9.8. This is twice the time taken for the ball to reach the apex of its flight. We use the second equation, your s=ut + 0.5at2
The displacement of the ball (u=x, a=0) is s=ut = 2x2/9.8
The displacement of the Earth (u=0, a=9.8 ), using the same equation, is s=0.5at2 = 2x2/9.8

That is, the ball is back to its starting point, and it takes the same time to go up as it does to go down.

If you want to simplify it, we can do this step by step. Let me know.

Stillbat least you had the courage to reply. Ski will do what she always does and pretend not to read this

Why would I pretend not to read the most ironically hysterical thread in recent memory?  Also, your pejorative use of "she" is blatantly sexist. Completely unsurprising and consistent with the rest of your peurile name calling.
Like I said before,  as trolls go, you're neither an exceptionally clever or entertaining one. Or at least not entertaining for the reasons you'd like to be.
Your entire act is stating your ignorance as fact while name calling and shouting "I'll keep destroying you with real physics" as you appeal to your own obviously misappropriated title of "physicsteacher".
And then you claim I'm running away and hiding from you and your massive intelligence, as opposed to simply ignoring you and your massive ego.

Fine (this is to both of you)


Give me a speed of the ball and I will do the video, by now you know it won't change the outcome.

Jane, wait for the video tomorrow, I'll make it nice and clear how the velocity of the ball is handled. Your ability to apply maths to physical concepts is weak, even if you think your number skills are not.

Give me a speed of the ball and I will do the video, by now you know it won't change the outcome.

Jane, wait for the video tomorrow, I'll make it nice and clear how the velocity of the ball is handled. Your ability to apply maths to physical concepts is weak, even if you think your number skills are not.

It won;t change the outcome. None of us are complaining about you choosing a speed of the ball (though if you had much practise with maths you ought to be perfectly capable of simply working with an unknown), we're complaining about your method. Why are you struggling to grasp that?

You don't need to make a whole video. Just point out, nice and simple, what the flaw in my calculation is.
Ironic you're accusing Ski of running away.