Thrown out of an FBO...

Air resistance. Do it in a vacuum and they will hit at the same time.

mike

"Roger (K8RI)" wrote in message
...
On Sat, 18 Nov 2006 14:47:52 +0100, Thomas Borchert
wrote:

Jose,

It was
obvious that heavier things fall faster (feather, stone, duh)


Drop a sheet of paper (airfoil) and a peanut that weighs the same off
a tall building. Which will get to the ground/pavement sooner (no
wind)


Actually, they don't.
Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

In article ,
Jim Logajan wrote:

Jose wrote:
It was obvious that heavier
things fall faster (feather, stone, duh)
Actually, they don't.

Correct. But it was obvious that they do.

Boy, I hate to be pedantic about this, but in a vacuum the heavier object
_will_ reach the surface of the earth faster than a lighter one if both
are released the same height above the ground. First, the forces are
equal on a mass Mo and the earth Me a distance h apart from their
gravitational centers; the equation being:
[etc.]

Interesting. You're saying the earth accelerates towards the heavy
object a little bit faster than towards the light one, right? But
there's only one earth, and if you drop them both at the same time,
don't they both hit the rising earth at the same time? You didn't
say they were released at the same time, but that was the implication
in the thread.

Mike Beede

Bob Noel wrote:
In article ,
Jim Logajan wrote:
But the bottom line is under "ideal" conditions a heavy stone "falls"
a teeny tiny miniscule bit faster to the earth than a light feather
would.

um, not quite. The force on the more massive object is still just
proportional to the earth's mass. What happens is the earth moves
towards the more massive object more so than towards the less massive
object.

Or have I totally botched my freshman physics?

You got it right. But to the person standing on the earth trying to time
the fall, the more massive object appears to drop a tiny bit faster (but
I'm not sure the drop time difference could even be measured for most
ordinary cases).

It's really a pedantic issue unless one is dealing with objects of
comparable masses, like the perturbations of planetary orbits due to other
planets.

But it was obvious that they do.
Uhm, no. And Newton's law never said anything remotely like that.

Um, yes. Lots of things that are obvious, are not true. The "fact"
that heavier objects fall faster was obvious. It is also wrong.

Newton's law of universal gravitation led to the result that masses fall
to earth at the same rate. Newton had some other discoveries too.

Jose
--
"Never trust anything that can think for itself, if you can't see where
it keeps its brain." (chapter 10 of book 3 - Harry Potter).
for Email, make the obvious change in the address.

Boy, I hate to be pedantic about this, but in a vacuum the heavier object
_will_ reach the surface of the earth faster than a lighter one if both
are released the same height above the ground.

That depends where they come from. If you pick up the feather (leaving
the stone on the ground), the stone's mass is part of the Earth's mass.
If you then drop the feather and pick up the stone, the feather
becomes part of the Earth's mass for that experiment.

The total mass is the same.

This is true in real experiments too, unless you can "beam" the stone
away while playing with the feather.

End of pedantry.

Jose
--
"Never trust anything that can think for itself, if you can't see where
it keeps its brain." (chapter 10 of book 3 - Harry Potter).
for Email, make the obvious change in the address.

On Sun, 19 Nov 2006 04:37:33 -0000, Jim Logajan
wrote:


You got it right. But to the person standing on the earth trying to time
the fall, the more massive object appears to drop a tiny bit faster (but
I'm not sure the drop time difference could even be measured for most
ordinary cases).

It's really a pedantic issue unless one is dealing with objects of
comparable masses, like the perturbations of planetary orbits due to other
planets.

Ya gonna drop the marble and the bowling ball at the same time?
Counting the Earth, that's three bodies. I thought the three-body
problem was insoluble?

Don

Jim,

You're right, of course.

--
Thomas Borchert (EDDH)

In article ,
Jim Logajan wrote:

You got it right. But to the person standing on the earth trying to time
the fall, the more massive object appears to drop a tiny bit faster (but
I'm not sure the drop time difference could even be measured for most
ordinary cases).

If the feather and hammer are dropped at the same time and are next
to each other. otoh - if the hammer is dropped at the true north pole
and the feather were dropped at the true south pole...

:-)

--
Bob Noel
Looking for a sig the
lawyers will hate

"Bob Noel" wrote in message
...
If the feather and hammer are dropped at the same time and are next
to each other. otoh - if the hammer is dropped at the true north pole
and the feather were dropped at the true south pole...

Ahhh, but more importantly, is the feather from an African or European
swallow...

--
"Your mother was a hamster and your father smells of elderberrys now go away
or I shall taunt you a second time"

Mike Beede wrote:
But
there's only one earth, and if you drop them both at the same time,
don't they both hit the rising earth at the same time? You didn't
say they were released at the same time, but that was the implication
in the thread.

I was treating the case where only two objects were in motion at any one
time - it's a lot simpler.

Since the implied problem is a three body problem it isn't going to be so
easy to prove that two objects of different masses released at the same
time will accelerate at the same rate towards the center of the earth. The
actual trajectories are going to be surprisingly complex.