Issac newton &the downhill test adventure

email hidden said:

I am 220 +/- my friend is 150 +/-. He has a relatively new mirage grupo
I have a mich-mach grupo but!!!?!: dura ace front and Phil rear hubs.
When we coast downhill I usually beat him often by significant
lengths. Is weight a factor [pace Issac]? I assume that it is the
quality of the hubs that makes the difference.
Thmx

Dear Stan,

There's probably not enough difference in bearing drag
between the two hubs to be measured by any readily available
tools.

You roll downhill faster than your friend because you weigh
almost 50% more than he does, but your frontal area hasn't
increased anywhere near 50%.

Gravity is pulling you down 50% harder, but your wind drag
doesn't hold you back that much--you have to go faster to
generate enough wind drag to match gravity and stop
accelerating.

In a nutshell, volume and mass tend to increase with the
cube of height, but surface area and wind drag tend to
increase more slowly, with the square of height.

Compare a cube 1x1x1 to a cube 2x2x2. The small cube has one
square foot of frontal area to one cubic foot of volume,
corresponding to a 1 to 1 ratio of wind drag to gravity. The
large cube has only 4 square feet of frontal area to 8 cubic
feet of volume, a 1 to 2 ratio of wind drag to gravity. The
bigger cube has to go faster before its wind drag matches
the pull of gravity.

Online bicycle speed calculators show this sort of thing at
work:

http://www.kreuzotter.de/english/espeed.htm

Pick hands-on-drops, -7 for a decent downhill slope, 0
cadence, 0 watts power, and whatever weights and heights you
have in mind.

For a 150-lb rider 67.7 inches tall, the calculator predicts
a terminal velocity of 39.6 mph.

For a 220-lb rider 72 inches tall, the calculator predicts a
terminal velocity of 43.8 mph, 4.2 mph faster.

Cheers,

Carl Fogel

Quoted message said:

I am 220 +/- my friend is 150 +/-. He has a relatively new mirage
grupo I have a mich-mach grupo but!!!?!: dura ace front and Phil rear
hubs. When we coast downhill I usually beat him often by significant
lengths. Is weight a factor [pace Issac]? I assume that it is the
quality of the hubs that makes the difference.
Thmx

Uh... duh... Galileo did this little test a little while ago. He dropped
weights from the Leaning Tower of Pepperoni Pizza and determined, since the
heavier weight hit the ground first, that heavy things fall faster.

Think about it... drop a feather and a bowling ball at the same time. Which
one hits the ground first?

So, since you weigh more, you "fall" down the hills faster. Gosh, physics
is easy to understand... why is it so hard to grasp?

I am so going to hell for this post. *send*
--
Phil, Squid-in-Training

Quoted message said:

I am so going to hell for this post. *send*
--
Phil, Squid-in-Training

If Hell were the destination of Internet misinformation promulgators,
it would be a lot more crowded than it is today! I think you are safe.
On this count at least!

Joseph

U¿ytkownik "Phil, Squid-in-Training" napisa³ w wiadomo¶ci
news:kBm1g.3550$B42.2232@dukeread05...

Quoted message said:

Think about it... drop a feather and a bowling ball at the same time.
Which one hits the ground first?

Depends on a planet - does it have an atmosphere or not? We don't know where
stankurz and his friend are riding.

--
Cheers
marcin
www.enduro.95mb.com

Quoted message said:

I am 220 +/- my friend is 150 +/-. He has a relatively new mirage grupo
I have a mich-mach grupo but!!!?!: dura ace front and Phil rear hubs.
When we coast downhill I usually beat him often by significant
lengths. Is weight a factor [pace Issac]? I assume that it is the
quality of the hubs that makes the difference.
Thmx

Assuming you both start down the hill at the same speed, and all other
things equal, your friend will coast further. Simply stated he has a
higher ratio of energy/wind resistance.
EJ in NJ

Quoted message said:

I am 220 +/- my friend is 150 +/-. He has a relatively new mirage grupo
I have a mich-mach grupo but!!!?!: dura ace front and Phil rear hubs.
When we coast downhill I usually beat him often by significant
lengths. Is weight a factor [pace Issac]? I assume that it is the
quality of the hubs that makes the difference.
Thmx

Obey gravity, it's the Law......

In article <kBm1g.3550$B42.2232@dukeread05>,
"Phil, Squid-in-Training" <[email hidden]>

Quoted message said:

Quoted message said:

I am 220 +/- my friend is 150 +/-. He has a relatively new mirage
grupo I have a mich-mach grupo but!!!?!: dura ace front and Phil
rear hubs. When we coast downhill I usually beat him often by
significant lengths. Is weight a factor [pace Issac]? I assume that
it is the quality of the hubs that makes the difference. Thmx

Uh... duh... Galileo did this little test a little while ago. He
dropped weights from the Leaning Tower of Pepperoni Pizza and
determined, since the heavier weight hit the ground first, that heavy
things fall faster.

Think about it... drop a feather and a bowling ball at the same time.
Which one hits the ground first?

How about in a vacuum?

email hidden said:

I am 220 +/- my friend is 150 +/-. He has a relatively new mirage grupo
I have a mich-mach grupo but!!!?!: dura ace front and Phil rear hubs.
When we coast downhill I usually beat him often by significant
lengths. Is weight a factor [pace Issac]? I assume that it is the
quality of the hubs that makes the difference.

Weight and the tires will make more difference than the hubs. It
takes a truly abysmal bearing (by bike hubs standards) to make a
difference you'd see in this area. None of those hubs has a bearing
tat will produce enough drag to show up here. On the other hand,
significant variances in rolling resistances between tires are common,
but that could go either way; if you've got the higher-resistance
tires, it would reduce the difference, while if the other rider has
them, it would contribute to it.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

Ernie Willson said:

Quoted message said:

I am 220 +/- my friend is 150 +/-. He has a relatively new mirage grupo
I have a mich-mach grupo but!!!?!: dura ace front and Phil rear hubs.
When we coast downhill I usually beat him often by significant
lengths. Is weight a factor [pace Issac]? I assume that it is the
quality of the hubs that makes the difference.
Thmx

Assuming you both start down the hill at the same speed, and all other
things equal, your friend will coast further. Simply stated he has a
higher ratio of energy/wind resistance.

I think you got that backwards. The lighter rider has the
disadvantage in this...until they hit the next climb.

--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

On Wed, 19 Apr 2006 12:11:08 +0200, "Marcin J." <[email hidden]>

Quoted message said:

U¿ytkownik "Phil, Squid-in-Training" napisa³ w wiadomo¶ci
news:kBm1g.3550$B42.2232@dukeread05...

Quoted message said:

Think about it... drop a feather and a bowling ball at the same time.
Which one hits the ground first?

Depends on a planet - does it have an atmosphere or not? We don't know where
stankurz and his friend are riding.

And there's no discussion of relativistic effects, either.
--
Typoes are a feature, not a bug.
Some gardening required to reply via email.
Words processed in a facility that contains nuts.

Werehatrack said:

And there's no discussion of relativistic effects, either.

Yes! The key question is not "who goes fastest?" but "who ages
slowest?"

"Phil, Squid-in-Training" wrote: (clip) So, since you weigh more, you
"fall" down the hills faster. Gosh, physics is easy to understand...
(clip)
^^^^^^^^^^^^^^^^
Oy, do YOU have a wrong number!

<[email hidden]> wrote: I am 220 +/- (clip)
^^^^^^^^^^^^^^^^
Need more information. Would that be single phase or three phase?

In article
<[email hidden]>,

Tim McNamara said:

In article <kBm1g.3550$B42.2232@dukeread05>,
"Phil, Squid-in-Training" <[email hidden]>

Quoted message said:

Quoted message said:

I am 220 +/- my friend is 150 +/-. He has a relatively new mirage
grupo I have a mich-mach grupo but!!!?!: dura ace front and Phil
rear hubs. When we coast downhill I usually beat him often by
significant lengths. Is weight a factor [pace Issac]? I assume that
it is the quality of the hubs that makes the difference. Thmx

Uh... duh... Galileo did this little test a little while ago. He
dropped weights from the Leaning Tower of Pepperoni Pizza and
determined, since the heavier weight hit the ground first, that heavy
things fall faster.

Think about it... drop a feather and a bowling ball at the same time.
Which one hits the ground first?

How about in a vacuum?

Tim, you misread Phil's article.

--
Michael Press

"Michael Press" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

In article
<[email hidden]>,

Tim McNamara said:

In article <kBm1g.3550$B42.2232@dukeread05>,
"Phil, Squid-in-Training" <[email hidden]>

Quoted message said:

[email hidden] wrote:
> I am 220 +/- my friend is 150 +/-. He has a relatively new mirage
> grupo I have a mich-mach grupo but!!!?!: dura ace front and Phil
> rear hubs. When we coast downhill I usually beat him often by
> significant lengths. Is weight a factor [pace Issac]? I assume
> that
> it is the quality of the hubs that makes the difference. Thmx

Uh... duh... Galileo did this little test a little while ago. He
dropped weights from the Leaning Tower of Pepperoni Pizza and
determined, since the heavier weight hit the ground first, that
heavy
things fall faster.

Think about it... drop a feather and a bowling ball at the same
time.
Which one hits the ground first?

How about in a vacuum?

Tim, you misread Phil's article.

and so did I............. the Equivalence Principle says that
gravitational mass is equal to inertial mass and that all objects fall
at the same rate in a vacuum. According to GR, gravity is not a force
but a distortion of space. The feeling of weighlessness during freefall
is unique for an accelerating body i.e. any other acceleration is
accompanied by a feeling of being pushed.

Phil H

<[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

email hidden said:

I am 220 +/- my friend is 150 +/-. He has a relatively new mirage
grupo
I have a mich-mach grupo but!!!?!: dura ace front and Phil rear hubs.
When we coast downhill I usually beat him often by significant
lengths. Is weight a factor [pace Issac]? I assume that it is the
quality of the hubs that makes the difference.
Thmx

Dear Stan,

There's probably not enough difference in bearing drag
between the two hubs to be measured by any readily available
tools.

You roll downhill faster than your friend because you weigh
almost 50% more than he does, but your frontal area hasn't
increased anywhere near 50%.

Gravity is pulling you down 50% harder, but your wind drag
doesn't hold you back that much--you have to go faster to
generate enough wind drag to match gravity and stop
accelerating.

In a nutshell, volume and mass tend to increase with the
cube of height, but surface area and wind drag tend to
increase more slowly, with the square of height.

Compare a cube 1x1x1 to a cube 2x2x2. The small cube has one
square foot of frontal area to one cubic foot of volume,
corresponding to a 1 to 1 ratio of wind drag to gravity. The
large cube has only 4 square feet of frontal area to 8 cubic
feet of volume, a 1 to 2 ratio of wind drag to gravity. The
bigger cube has to go faster before its wind drag matches
the pull of gravity.

Online bicycle speed calculators show this sort of thing at
work:

http://www.kreuzotter.de/english/espeed.htm

Pick hands-on-drops, -7 for a decent downhill slope, 0
cadence, 0 watts power, and whatever weights and heights you
have in mind.

For a 150-lb rider 67.7 inches tall, the calculator predicts
a terminal velocity of 39.6 mph.

For a 220-lb rider 72 inches tall, the calculator predicts a
terminal velocity of 43.8 mph, 4.2 mph faster.

Welcome back Carl!

Phil H

In article <[email hidden]>,

Phil Holman' piholmanc@yourservice said:

"Michael Press" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

In article
<[email hidden]>,

Tim McNamara said:

In article <kBm1g.3550$B42.2232@dukeread05>,
"Phil, Squid-in-Training" <[email hidden]>
wrote:

> [email hidden] wrote:
> > I am 220 +/- my friend is 150 +/-. He has a relatively new mirage
> > grupo I have a mich-mach grupo but!!!?!: dura ace front and Phil
> > rear hubs. When we coast downhill I usually beat him often by
> > significant lengths. Is weight a factor [pace Issac]? I assume
> > that
> > it is the quality of the hubs that makes the difference. Thmx
>
> Uh... duh... Galileo did this little test a little while ago. He
> dropped weights from the Leaning Tower of Pepperoni Pizza and
> determined, since the heavier weight hit the ground first, that
> heavy
> things fall faster.
>
> Think about it... drop a feather and a bowling ball at the same
> time.
> Which one hits the ground first?

How about in a vacuum?

Tim, you misread Phil's article.

and so did I............. the Equivalence Principle says that
gravitational mass is equal to inertial mass and that all objects fall
at the same rate in a vacuum. According to GR, gravity is not a force
but a distortion of space. The feeling of weighlessness during freefall
is unique for an accelerating body i.e. any other acceleration is
accompanied by a feeling of being pushed.

and from the heavier body's point of view it takes longer
to reach the ground.

The USA global positioning satellite system is based upon
accurate clocks aboard orbiting satellites broadcasting
their time and other information. When the system was
designed they naturally built the Lorentz transformations
into the satellite clocks and computers. One bright light
said that they also needed to add in the variance of clock
rate from the gravitational field differences between
terra firma and the satellite altitude; but he was
ignored. When the system was being tested they discovered
systematic errors; eventually determined that the errors
were from gravitational effects on the clocks that were
tuned at sea level, but running at a few hundred
kilometers altitude.

--
Michael Press

"Michael Press" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

In article <[email hidden]>,

Phil Holman' piholmanc@yourservice said:

"Michael Press" <[email hidden]> wrote in message
news:[email hidden]...

Quoted message said:

In article
<[email hidden]>,
Tim McNamara <[email hidden]> wrote:

> In article <kBm1g.3550$B42.2232@dukeread05>,
> "Phil, Squid-in-Training" <[email hidden]>
> wrote:
>
> > [email hidden] wrote:
> > > I am 220 +/- my friend is 150 +/-. He has a relatively new
> > > mirage
> > > grupo I have a mich-mach grupo but!!!?!: dura ace front and
> > > Phil
> > > rear hubs. When we coast downhill I usually beat him often by
> > > significant lengths. Is weight a factor [pace Issac]? I assume
> > > that
> > > it is the quality of the hubs that makes the difference. Thmx
> >
> > Uh... duh... Galileo did this little test a little while ago.
> > He
> > dropped weights from the Leaning Tower of Pepperoni Pizza and
> > determined, since the heavier weight hit the ground first, that
> > heavy
> > things fall faster.
> >
> > Think about it... drop a feather and a bowling ball at the same
> > time.
> > Which one hits the ground first?
>
> How about in a vacuum?

Tim, you misread Phil's article.

and so did I............. the Equivalence Principle says that
gravitational mass is equal to inertial mass and that all objects
fall
at the same rate in a vacuum. According to GR, gravity is not a force
but a distortion of space. The feeling of weighlessness during
freefall
is unique for an accelerating body i.e. any other acceleration is
accompanied by a feeling of being pushed.

and from the heavier body's point of view it takes longer
to reach the ground.

The USA global positioning satellite system is based upon
accurate clocks aboard orbiting satellites broadcasting
their time and other information. When the system was
designed they naturally built the Lorentz transformations
into the satellite clocks and computers. One bright light
said that they also needed to add in the variance of clock
rate from the gravitational field differences between
terra firma and the satellite altitude; but he was
ignored. When the system was being tested they discovered
systematic errors; eventually determined that the errors
were from gravitational effects on the clocks that were
tuned at sea level, but running at a few hundred
kilometers altitude.

Does this explain the orbital precession of Mercury and FermiLab's
particle beams?

Phil H

In article
<[email hidden]>,
"Phil Holman" <piholmanc@yourservice> wrote:

[...]

Quoted message said:

Does this explain the orbital precession of Mercury and FermiLab's
particle beams?

The General Theory of Relativity does account for the
value of the precession of the perihelion of Mercury where
the inverse square law of gravitation does not. Precession
of perihelion of a planet is
6 * PI * k^2 * m^2 / h^2
where
k is the gravitational constant
m is the mass of the planet
h is the angular momentum of the planet.
43" per century for Mercury.

I do not know anything about FermiLab particle beam
precession.

--
Michael Press