Looking for an intelligent argument. (Terminal Velocity)

Quote from: cbarnett97 on August 17, 2008, 03:36:24 PM

so where is the F=ma in the freebody diagram that allows you to enter it into the equation to make that relationship?

So now I have to declare Newton's second law of motion in every freebody diagram I draw before I can use it?

Lets make a step back then; what accelerates according to the FE model, the object released of the earth?

Quote from: cbarnett97 on August 17, 2008, 03:41:42 PM

Lets make a step back then; what accelerates according to the FE model, the object released of the earth?

Ignoring air resistance, the Earth. Allowing for air resistance, both.

exactly so we would have F=ma-R but according to the FE model the acceleration of the object is zero, so taking that into account we have:
F=m(0)-R which leads us to F=-R

Quote from: cbarnett97 on August 17, 2008, 03:45:51 PM

exactly so we would have F=ma-R but according to the FE model the acceleration of the object is zero, so taking that into account we have:
F=m(0)-R which leads us to F=-R

So a force is applied to an object but doesn't cause it to accelerate?

it accelerates but at a different rate than in the RE model and the acceleration is dependent on the Air resistance so that is why 2 object with different masses would have the same terminal velocity if their air resistance was the same

Quote from: cbarnett97 on August 17, 2008, 03:50:38 PM

it accelerates but at a different rate than in the RE model and the acceleration is dependent on the Air resistance so that is why 2 object with different masses would have the same terminal velocity if their air resistance was the same

No, the rate of acceleration would be the same in RE as in FE. And terminal velocity doesn't have anything to do with it if we're talking about a drop from a rooftop; what matters is how long it takes to reach that state of equilibrium.

Why are you using my quote as a signature, that quote disproved FEG when you tried to use the density of the RE sun in a FEG sun calculation.

Quote from: cbarnett97 on August 17, 2008, 03:50:38 PM

it accelerates but at a different rate than in the RE model and the acceleration is dependent on the Air resistance so that is why 2 object with different masses would have the same terminal velocity if their air resistance was the same

No, the rate of acceleration would be the same in RE as in FE. And terminal velocity doesn't have anything to do with it if we're talking about a drop from a rooftop; what matters is how long it takes to reach that state of equilibrium.

So show me how you would calculate the terminal velocity of an object using the FE model

No it won't.

It will. 

Quote from: cbarnett97 on August 17, 2008, 04:00:38 PM

So show me how you would calculate the terminal velocity of an object using the FE model

It would simply be the point at which the falling object is accelerating at the same rate as the Earth is below it; that is to say, the point at which -R = -mg (incidentally, it probably wasn't a good idea to pick down as positive, since all the forces we are working with in the FE model go up). Assuming that R is a linear function of v such that R = kv, then one would simply evaluate v = mg / k.

Quote from: sokarul on August 17, 2008, 04:08:09 PM

It will. 

It really won't.

So the FE model uses gravity now?

or should it just look like this v= sqrt(2ma/(CpA) but of course the object is not accelerating so therefore you will just end up with zero

So that tell us that there is no Terminal velocity

If I throw a ball up in the air, how does it come back down?  Or for that matter, how does it slow on the way up? 

Quote from: cbarnett97 on August 17, 2008, 04:11:25 PM

So the FE model uses gravity now?

or should it just look like this v= sqrt(2ma/(CpA) but of course the object is not accelerating so therefore you will just end up with zero

So that tell us that there is no Terminal velocity

What was the point of asking me to show how I would calculate terminal velocity if you were going to ignore my solution and draw your own idiotic conclusions anyway?

Quote from: sokarul on August 17, 2008, 04:12:53 PM

If I throw a ball up in the air, how does it come back down?  Or for that matter, how does it slow on the way up? 

It doesn't. You accelerate up to it.

Quote from: cbarnett97 on August 17, 2008, 04:11:25 PM

So the FE model uses gravity now?

or should it just look like this v= sqrt(2ma/(CpA) but of course the object is not accelerating so therefore you will just end up with zero

So that tell us that there is no Terminal velocity

What was the point of asking me to show how I would calculate terminal velocity if you were going to ignore my solution and draw your own idiotic conclusions anyway?

Quote from: sokarul on August 17, 2008, 04:12:53 PM

If I throw a ball up in the air, how does it come back down?  Or for that matter, how does it slow on the way up? 

It doesn't. You accelerate up to it.

Just curious if you understood your model correctly

So you like non inertial FOR, cool. I am of course talking about the RE but you already knew that.  

Have you ever heard of the twin paradox? Do you know what the solution to the twin paradox is?  

Let us look at all the terms here
F=ma-.5CpAv²

m=Mass of object
a= acceleration of object
C=Drag coefficient
p= Denisty of air
A= cross sectional area of object
v= velocity of air passing by object

So tell me where the error is

I am talking about both models. Because of the equivalence principle, what I have said is valid for both FET and RET.

Yes I have heard of the twin paradox, and yes I am aware of its solution. I don't see how it is relevant to this discussion, however.

I don't expect you to know what I am getting at.

The twin paradox shows who has the effects of velocity.

When I throw a ball I first must accelerate it.

This is non inertial.

Once again, there are FORs in the RE that show gravitation causing acceleration. 

No there aren't.

Quote from: interstellarsphere on August 17, 2008, 03:58:28 PM

Why are you using my quote as a signature, that quote disproved FEG when you tried to use the density of the RE sun in a FEG sun calculation.

a RE and FE sun have different masses and volumes therefore you cant mix the numbers.
So you trying to do so, trying to use the RE density n a FE equation makes no senseand shows your ignorant.

Quote from: cbarnett97 on August 17, 2008, 04:15:37 PM

Just curious if you understood your model correctly

I'm not the one saying there is no such thing as terminal velocity.

Let us look at all the terms here
F=ma-.5CpAv²

m=Mass of object
a= acceleration of object
C=Drag coefficient
p= Denisty of air
A= cross sectional area of object
v= velocity of air passing by object

So tell me where the error is

That is exactly the point.  The object continuously accelerates upwards.  When the acceleration of the object reaches 9.8m/s^2, it is no longer accelerating relative to the earth, thereby having reached its terminal velocity.

Quote from: cbarnett97 on August 16, 2008, 09:16:49 PM

What we should be asking is that if we use the FE model to predict the terminal velocity of an object,  objects with same air resistance but different masses should have the same terminal velocity but in reality they do not.

Uh, no.

Air resistance.

Uh, no.