Author Topic: So much news, so little sense  (Read 4450 times)

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Plane

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Re: So much news, so little sense
« Reply #60 on: May 29, 2007, 05:42:17 PM »
Are the datum related in a demonstrable way ?

Are all major factors accounted for?

Amianthus

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Re: So much news, so little sense
« Reply #61 on: May 29, 2007, 05:47:19 PM »
So if I'm calculating the path of a bullet, I can't put muzzle velocity together with atmospheric  pressure together with the mass of the bullet because that's mixing data?

Actually, you create vectors for the muzzle velocity, pull of gravity, and wind velocity, then perform vector addition.

Since all the individual data collected are vectors, they are all the same type of data.

I'll stick with real science.
Do not anticipate trouble, or worry about what may never happen. Keep in the sunlight. (Benjamin Franklin)

Amianthus

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Re: So much news, so little sense
« Reply #62 on: May 29, 2007, 05:54:09 PM »
mass of the bullet because that's mixing data?

Oh yeah, in case you hadn't heard...

I know you don't keep up with the latest in scientific developments...

There was this guy named Galileo who proved that the acceleration of gravity is constant regardless of mass. Two bullets fired at the same time (or one fired and one dropped), regardless of mass, will hit the ground in exactly the same length of time.

It's one of those law thingies.
Do not anticipate trouble, or worry about what may never happen. Keep in the sunlight. (Benjamin Franklin)

Plane

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Re: So much news, so little sense
« Reply #63 on: May 29, 2007, 06:05:03 PM »
mass of the bullet because that's mixing data?

Oh yeah, in case you hadn't heard...

I know you don't keep up with the latest in scientific developments...

There was this guy named Galileo who proved that the acceleration of gravity is constant regardless of mass. Two bullets fired at the same time (or one fired and one dropped), regardless of mass, will hit the ground in exactly the same length of time.

It's one of those law thingies.
I think MT has a point.

It had to happen someday .

You do need to know mass , and cross sectional area , and air density to compute the energy lost to air resistance.

When firing the Paris Gun the variable density at hight had to be compensated for , as well as the amount of earth rotation differential caused by Coriolis force.  A bullet is a good example of haveing a lot of factors matter.
 True , all of the factors can be shown as vectors , but I think that MT could possibly relate his data .

Of course in spite of computeing a lot for each shot the Paris Gun had a reliably large error. Cahos rears his head in circumstances where small factors are multiplyed over time and the result is a situation sensitive to initial conditions.

Life is like that.

Michael Tee

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Re: So much news, so little sense
« Reply #64 on: May 29, 2007, 06:06:12 PM »
I've got a little experiment for you to try.  Take a ping-poing paddle and whack a ping-pong ball.  See how far the ball goes.  Take the same ping-poing paddle and whack a standing locomotive with it.  See how far the locomotive goes.  Measure the mass of the ping-pong ball.  Measure the mass of the locomotive.  Assume equal propulsive force applied to each.  Try to figure out why the ping-pong ball went farther than the locomotive.  Think the mass of the two projectiles had anything to do with the variation in distance travelled?

Amianthus

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Re: So much news, so little sense
« Reply #65 on: May 29, 2007, 06:10:57 PM »
I've got a little experiment for you to try.  Take a ping-poing paddle and whack a ping-pong ball.  See how far the ball goes.  Take the same ping-poing paddle and whack a standing locomotive with it.  See how far the locomotive goes.  Measure the mass of the ping-pong ball.  Measure the mass of the locomotive.  Assume equal propulsive force applied to each.  Try to figure out why the ping-pong ball went farther than the locomotive.  Think the mass of the two projectiles had anything to do with the variation in distance travelled?

Mass has nothing to do with the gravity vector.

It is already included in the muzzle velocity vector.

Mass on it's own is not used in ballistic trajectory calculations.

I guess you also need a drag vector, which would use the cross section.
« Last Edit: May 29, 2007, 06:14:01 PM by Amianthus »
Do not anticipate trouble, or worry about what may never happen. Keep in the sunlight. (Benjamin Franklin)

Plane

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Re: So much news, so little sense
« Reply #66 on: May 29, 2007, 06:14:32 PM »
I've got a little experiment for you to try.  Take a ping-poing paddle and whack a ping-pong ball.  See how far the ball goes.  Take the same ping-poing paddle and whack a standing locomotive with it.  See how far the locomotive goes.  Measure the mass of the ping-pong ball.  Measure the mass of the locomotive.  Assume equal propulsive force applied to each.  Try to figure out why the ping-pong ball went farther than the locomotive.  Think the mass of the two projectiles had anything to do with the variation in distance travelled?

If a ping pong ball is dropped in a pipe evacuated of air, it will beat the Locomotive to the ground dropped an equal hight through air resistance.

If air resistance is simular and speed is simular balistic path is simular reguardless of mass.

Did you start by includeing the amount of propulsive force? The amouont of propulsive force vs mass is another question than the one you started with.

Michael Tee

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Re: So much news, so little sense
« Reply #67 on: May 29, 2007, 07:54:41 PM »
<<Mass on it's own is not used in ballistic trajectory calculations.>>

It's not used in the calculations because you usually have muzzle velocity.  But if you didn't, you could calculate trajectory from mass and propulsive force.  Except that (according to you) the data would be mixing - - hey!  mass doesn't go with propulsive force or atmospheric pressure.  Mass isn't a vector!  Keep mass out of the calculations!

Sheer craziness.  Of course, you could factor in mass, propulsive force, atmospheric pressure or air density, gravity etc. and perform meaningful calculations.   Mass is a datum just like propulsive force and the others.  You are making less and less sense the deeper you get into this.

Amianthus

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Re: So much news, so little sense
« Reply #68 on: May 29, 2007, 08:45:55 PM »
Sheer craziness.  Of course, you could factor in mass, propulsive force, atmospheric pressure or air density, gravity etc. and perform meaningful calculations.   Mass is a datum just like propulsive force and the others.  You are making less and less sense the deeper you get into this.

Hey, I got more data to add in.

I didn't have just 3 points to put into my calculation!

My computer has a black keyboard.
The temperature outside at the time of my last post was 74 degrees.
I had recently made a post about swastikas on veterans graves.

Hey, there was actually 6 points that I used.

Wait a minute.

I was watching CNN at the time.

Make that 7 points.

Wait a minute...

Where do you cut off? They must all be involved, after all they were all there at the same time...
Do not anticipate trouble, or worry about what may never happen. Keep in the sunlight. (Benjamin Franklin)

Michael Tee

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Re: So much news, so little sense
« Reply #69 on: May 29, 2007, 11:16:04 PM »
A good scientist (me, for instance) would pick only relevant points - - the three I picked were essential to your conclusion.  The colour of your keyboard, for example, was not.

Amianthus

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Re: So much news, so little sense
« Reply #70 on: May 29, 2007, 11:17:26 PM »
A good scientist (me, for instance) would pick only relevant points - - the three I picked were essential to your conclusion.  The colour of your keyboard, for example, was not.

Sure it is. I typed the message on it, so it was involved. And the temperature could have affected my attitude.
Do not anticipate trouble, or worry about what may never happen. Keep in the sunlight. (Benjamin Franklin)

Plane

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Re: So much news, so little sense
« Reply #71 on: May 29, 2007, 11:59:13 PM »
A good scientist (me, for instance) would pick only relevant points - - the three I picked were essential to your conclusion.  The colour of your keyboard, for example, was not.

yes , how are the three datum interrelated?