Looking for an intelligent argument. (Terminal Velocity)

Since none of my equations have been shown to be incorrect, I now declare:

A victory for FE!

Learn how numerical model then you will learn how to properly solve the equation.

Quote from: cbarnett97 on August 23, 2008, 10:56:34 PM

so acceleration caused by gravity is the equivalent to acceleration caused by air, wow that is new to me

Equal, yes.  No wonder you have failed so badly in this thread...

So if I have 2 carts on a table and with one I accelerate it by dropping a mass off the side of the table and the other cart I accelerate it by turning on a fan that keeps blowing faster and faster the 2 carts will accelerate at the same rate?

Ive just dived into this thread. Havent read the whole thing. I dont really think I can give intelligent arguments but one can try..

FE: Its about acceleration. DE accelerates earth. But more than fex stuff on earth, like people. Thats why earth accelerates into us when where in air. When "falling" we actually just decrease our speed upwards thus it feels like falling. Ok that is clear.

So here is my first question. How does DE affect mass differently? I guess that it affects more mass more. Earth is obviously more mass than water, air, schooners and so on. So the power of acceleration must be at largest.. yes where?

Which leads to the second question. How is the underside of earth, kept in place? Why isnt it torn apart downwards? Or maybe it does but slowly? Or made of really strong material at the bottom? Or the bottom is the most dense part, so thats where accelerating force is strongest?

Look ma, no math!

Quote from: TheEngineer on August 25, 2008, 08:18:26 AM

Since none of my equations have been shown to be incorrect, I now declare:

A victory for FE!

Learn how numerical model then you will learn how to properly solve the equation.

So you spent three days trying to break my equations and found that you still can't? 

Victory for FE!

Quote from: cbarnett97 on August 27, 2008, 12:31:05 PM

Quote from: TheEngineer on August 25, 2008, 08:18:26 AM

Since none of my equations have been shown to be incorrect, I now declare:

A victory for FE!

Learn how numerical model then you will learn how to properly solve the equation.

So you spent three days trying to break my equations and found that you still can't? 

Victory for FE!

Why is it a victory for the FE?

Because it clearly is.

Quote from: TheEngineer on August 27, 2008, 03:38:17 PM

Quote from: cbarnett97 on August 27, 2008, 12:31:05 PM

Quote from: TheEngineer on August 25, 2008, 08:18:26 AM

Since none of my equations have been shown to be incorrect, I now declare:

A victory for FE!

Learn how numerical model then you will learn how to properly solve the equation.

So you spent three days trying to break my equations and found that you still can't? 

Victory for FE!

Why is it a victory for the FE?

you must remeber how the FE operates, they destroy the laws of math and science and then bury their heads in the ground so they can claim a victory

That's quite ironic from someone that can't break a 'simple algebra' equation.  We are still waiting for you to impress us with your middle school math skills and show my equation to be wrong.

Learn how numerical model then you will learn how to properly solve the equation.

Now you may need to look it up on wiki to learn what the term is. If for some reason it is not there let me know and I will explain it to you.

I've been waiting all this time for you to explain how my equations are wrong.  If you need to post pictures from your 8th grade math book, go ahead.

Try to break this equation:
1 = 1

Win for RE!!

I've been waiting all this time for you to explain how my equations are wrong.  If you need to post pictures from your 8th grade math book, go ahead.

1/2C_dpAv²=ma

C_d = Known
p = Known
A = Known
v = a_et = Known
m = Known
a = Unknown


So why would you solve for a known?

I'm sorry, what known am I solving for?

I'm sorry, what known am I solving for?

you would solve for an unknown

That's what I did.  You said I am solving for a known.  What known am I solving for?  Do you even know how to read an equation?

Quote from: cbarnett97 on August 19, 2008, 12:50:32 AM

Bump... Still waiting on an answer

v_t=sqrt(2*a_e*m/(C_d*A*rho))

Where a_e is the acceleration of the FE, m is the mass of the object, C_d is the coefficient of drag, A is the projected area of the object, and rho is the density of the medium

I can provide the derivation if you want it.  But your 'intellegence' should allow you to do it yourself.

in case you forgot, here is where you solve for a known. As well as pluggin in values that do not belong in the equation, but it was a good job of writing down the RE equation

This is hilarious.

in case you forgot, here is where you solve for a known.

Uh, v_t is not known.  That is your issue, in case you forgot.

As well as pluggin in values that do not belong in the equation, but it was a good job of writing down the RE equation

Which variables don't belong in the equation?  Oh, did you forget about the derivation that I provided?  It clearly shows the FE derivation.

Quote from: cbarnett97 on August 28, 2008, 08:37:58 PM

in case you forgot, here is where you solve for a known.

Uh, v_t is not known.  That is your issue, in case you forgot.

Quote

As well as pluggin in values that do not belong in the equation, but it was a good job of writing down the RE equation

Which variables don't belong in the equation?  Oh, did you forget about the derivation that I provided?  It clearly shows the FE derivation.

in the FE model v is a known putting a little subscript next to it does not change it into an unknown, as well as you can not plug in the accerleration of the earth in the equation, if you think you can go back and read up on free body diagrams. the acceleration of the air, which is in the system is used to find the velocity.

Terminal velocity is not known.  That is what we are solving for.

In case you forgot:

The drag force on a body in a fluid is given by
 
F = .5*C_d*v²*A*rho                                                       (1)

where C_d is the drag coefficient, v is the velocity of the object, A is the cross sectional area of the object and rho is the density of the fluid.

We know from Newton's Second Law of Motion that

F = m*a_o                                                                      (2)

where F is force, m is the mass of the object and a_o is the acceleration of the object.  Rearranging (2) gives us

a_o = F/m                                                                       (3)

Combining (3) and (1) gives

a_o = C_d*v²*A*rho/(2*m)                                                 (4)

Now, an object that has reached terminal velocity, v_t, has no relative acceleration to the Earth.  Applying this to the FE, that means that the object must have an upwards acceleration equal to that of the Earth's.  It follows then, that

a_e - a_o = 0                                                                   (5)

where a_e is the acceleration of the Earth and a_o is the acceleration of the object. 

Rearranging (5) gives

a_e = a_o                                                                        (6)

which, by examination, is correct for all objects whose height is not changing relative to the Earth (aircraft for example). 

Combining (6) and (4) leaves us with the equation

a_e = C_d*v_t²*A*rho/(2*m)                                              (7)

Performing simple algebra on (7) yields the equation

v_t = sqrt(2*a_e*m/(Cd*A*rho)                                          (8)

which can easily been seen to be the exact same equation as the one for the RE, with the exception that a_e refers to the acceleration of the Earth and a in the RE equation refers to the acceleration due to gravity.

Using your numbers, we see that the terminal velocity on the FE is 22.1426 m/s.

in the FE model v is a known

What is its value, then?

Quote from: cbarnett97 on August 28, 2008, 09:22:33 PM

in the FE model v is a known

What is its value, then?

its value is,
v=a_et

its value is,
v=a_et

Why isn't the person accelerating?

Quote from: Robosteve on August 28, 2008, 09:56:57 PM

Quote from: cbarnett97 on August 28, 2008, 09:22:33 PM

in the FE model v is a known

What is its value, then?

its value is,
v=a_et

Do you know what the difference is between your v and my v_t?  I would guess not.

Quote from: cbarnett97 on August 29, 2008, 02:44:41 AM

Quote from: Robosteve on August 28, 2008, 09:56:57 PM

Quote from: cbarnett97 on August 28, 2008, 09:22:33 PM

in the FE model v is a known

What is its value, then?

its value is,
v=a_et

Do you know what the difference is between your v and my v_t?  I would guess not.

you put a litttle t next to the v, are you trying to tell us that we can put a subscript next to a known quantity and that will magically change it into an unknown?

Are you really that stupid?

The t subscript indicates terminal velocity.  Which is what we are are trying to find out, which, by definition, makes it an unknown. 

What grade are you in?

Are you really that stupid?

The t subscript indicates terminal velocity.  Which is what we are are trying to find out, which, by definition, makes it an unknown. 

What grade are you in?

so a terminal velocity is no longer a velocity?

That is probably the dumbest thing you have ever posted.

That is probably the dumbest thing you have ever posted.

well that is the claim you are making

Uh, no I am not.  In fact:

The t subscript indicates terminal velocity.