OT: Why the US will never go metric....

[Archimedes' Lever]

On Wed, 16 Jun 2010 06:29:56 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

Does your scale report your weight in newtons?

John

No "scale" 'reports weight in Newtons'.

A force gauge 'reports' applied force in Newtons. Said force
application must be pushed against or pulled away from the calibrated
node of the measuring device. Said force gauge is NOT a "scale".

 

[Archimedes' Lever]

On Wed, 16 Jun 2010 09:31:57 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

1. About how much has my measured weight changed due to the change of
G with altitude?

Depends on the scale, and its calibrated range of operation, and the
atmospheric pressure.

The scale I gave you a picture of (link) shows you exactly what the
difference is in G.

 

[Archimedes' Lever]

On Wed, 16 Jun 2010 09:31:57 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

2. Is this significant to the measurement?

If one is measuring mass, yes. It matters.

If one is measuring "weight" it is ALWAYS relative to the calibration
position and circumstance.

If those are changed, the weight reading changes, even though the
weight hasn't.

If the operator is aware of this, and is aware of the degree of
precision or lack thereof that instills into this method of
determination, he can reasonably be expected to know how reliable any
reading from a simple weight scale provides.

 

[Archimedes' Lever]

On Wed, 16 Jun 2010 09:31:57 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

3. Is the position of the moon significant to the measurement?

John

Yes.

Again, if the operator wants precision, he needs to measure mass, and
use a balance to do so. If one only wants the precision reliance that a
weight scale provides, one cannot expect, reasonably or otherwise, that
the reading given on the scale can be considered an "exact" reading.

With the degree of error in mind, a reasonable operator would know that
it is pretty close, but would still be aware that it was measured against
the Earth's gravity, and not truly as compared against a reference mass
using a device that is not bound by Earths gravity to operate.

So, the Moon changes Earth's gravitational field in such a way that
a reading taken (with a weight scale) at any given point on Earth will
vary depending on where the Moon is at with reference to where the scale
is at.

 

[John Fields]

On Wed, 16 Jun 2010 09:31:57 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Wed, 16 Jun 2010 07:45:34 -0500, John Fields
jfields@austininstruments.com> wrote:

On Tue, 15 Jun 2010 19:42:04 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Tue, 15 Jun 2010 13:44:39 -0500, John Fields
jfields@austininstruments.com> wrote:

On Tue, 15 Jun 2010 07:00:03 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Tue, 15 Jun 2010 00:31:35 -0500, John Fields
jfields@austininstruments.com> wrote:

On Mon, 14 Jun 2010 08:25:57 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Mon, 14 Jun 2010 07:23:14 -0700, Archimedes' Lever
OneBigLever@InfiniteSeries.Org> wrote:

On Mon, 14 Jun 2010 07:19:37 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

Fluid of course. Few people ever measure force. And most liquids used
in everydat life have a s.g. near 1, so an ounce of tabasco is
unambiguous.

Hundreds, even thousands of folks measure force every day, and many of
those use ounces in their scales of measure. Many use Newtons.


Of course hundreds, maybe even thousands of people measure force every
day. But there are 300 million people in the USA. Most people never
measure force; they do measure weight, or mass actually.

---
Since weight is mass multiplied by the acceleration of gravity and
most people use scales instead of beam balances and calibrated
reference masses to do the measurement, they measure weight, not mass.

http://en.wikipedia.org/wiki/Weighing_scale



Most people in the world use SI units, and they weigh things in
kilograms. A kg is a unit of mass.

Whether they use springs or balance beams or load cells, the reported
result is mass. kg, not newtons.

---
Sorry, but no.

The result of the measurement is caused by a force acting on a mass,
the product of which is called a "newton" if the mass is 1kg and the
force is the attraction due to gravity, 9.8m/s˛.

Entirely wrong:

http://en.wikipedia.org/wiki/Newton_%28unit%29

---
Yup.

I got the mass wrong, (it should be about 102 grams) but the fact
still remains that what a scale does is measure weight, not mass.

OK, today's puzzler:

Suppose I weigh myself at home, using my ordinary spring-based
bathroom scale. Home is 365 feet above sea level. Now I drive to
Truckee; it takes about 3 hours if I push it, 80+ MPH except for the
speed trap at Clipper Gap. When I arrive I use the same scale to weigh
myself, now at 6400 feet. Latitude is about the same.

1. About how much has my measured weight changed due to the change of
G with altitude?

2. Is this significant to the measurement?

Rules: you have one minute to deliver an answer. Use no paper, pencils
or equivalent, calculators, computers, books, or any external
assistance or references of any kind. Keep your eyes closed. Do it
entirely in your head.

Extra credit, one more minute:

3. Is the position of the moon significant to the measurement?

---
That's too much like work; I decline.

 

[John Larkin]

On Wed, 16 Jun 2010 10:02:17 -0700, Archimedes' Lever
<OneBigLever@InfiniteSeries.Org> wrote:

On Wed, 16 Jun 2010 09:31:57 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

1. About how much has my measured weight changed due to the change of
G with altitude?

Depends on the scale, and its calibrated range of operation, and the
atmospheric pressure.

The scale I gave you a picture of (link) shows you exactly what the
difference is in G.

Time's up. You blew it.

John

 

[John Larkin]

On Wed, 16 Jun 2010 10:05:09 -0700, Archimedes' Lever
<OneBigLever@InfiniteSeries.Org> wrote:

On Wed, 16 Jun 2010 09:31:57 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

2. Is this significant to the measurement?


If one is measuring mass, yes. It matters.

If one is measuring "weight" it is ALWAYS relative to the calibration
position and circumstance.

If those are changed, the weight reading changes, even though the
weight hasn't.

If the operator is aware of this, and is aware of the degree of
precision or lack thereof that instills into this method of
determination, he can reasonably be expected to know how reliable any
reading from a simple weight scale provides.

Word salad. Do the math.

John

 

[John Larkin]

On Wed, 16 Jun 2010 10:10:27 -0700, Archimedes' Lever
<OneBigLever@InfiniteSeries.Org> wrote:

On Wed, 16 Jun 2010 09:31:57 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

3. Is the position of the moon significant to the measurement?

John

Yes.

The correct answer must be "no", since you're AlwaysWrong.

Again, if the operator wants precision, he needs to measure mass, and
use a balance to do so. If one only wants the precision reliance that a
weight scale provides, one cannot expect, reasonably or otherwise, that
the reading given on the scale can be considered an "exact" reading.

With the degree of error in mind, a reasonable operator would know that
it is pretty close, but would still be aware that it was measured against
the Earth's gravity, and not truly as compared against a reference mass
using a device that is not bound by Earths gravity to operate.

So, the Moon changes Earth's gravitational field in such a way that
a reading taken (with a weight scale) at any given point on Earth will
vary depending on where the Moon is at with reference to where the scale
is at.

Words, words, words. The answer would be numbers.

Your smart move would have been to ignore my post.

John

 

[John Larkin]

On Tue, 15 Jun 2010 23:34:50 -0700,
"JosephKK"<quiettechblue@yahoo.com> wrote:

On Tue, 15 Jun 2010 00:31:35 -0500, John Fields
jfields@austininstruments.com> wrote:

On Mon, 14 Jun 2010 08:25:57 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Mon, 14 Jun 2010 07:23:14 -0700, Archimedes' Lever
OneBigLever@InfiniteSeries.Org> wrote:

On Mon, 14 Jun 2010 07:19:37 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

Fluid of course. Few people ever measure force. And most liquids used
in everydat life have a s.g. near 1, so an ounce of tabasco is
unambiguous.

Hundreds, even thousands of folks measure force every day, and many of
those use ounces in their scales of measure. Many use Newtons.


Of course hundreds, maybe even thousands of people measure force every
day. But there are 300 million people in the USA. Most people never
measure force; they do measure weight, or mass actually.

---
Since weight is mass multiplied by the acceleration of gravity and
most people use scales instead of beam balances and calibrated
reference masses to do the measurement, they measure weight, not mass.

http://en.wikipedia.org/wiki/Weighing_scale

Balances compare the gravitationally induced forces of test masses versus
reference masses. Please note that this assumes that the gravitational
field is reasonably uniform in terms of area included in the balance the
masses to be compared and the distances between them. And many scales
measure deflection of (more or less) well documented structures deflected
by the forces in an assumed uniform gravitational field. Compare the
usefulness of balance versus scales in any accelerated (including
rotated) frame of reference.

Words, words, words. Do the puzzler.

John

 

[John Larkin]

On Wed, 16 Jun 2010 12:23:29 -0500, John Fields
<jfields@austininstruments.com> wrote:

On Wed, 16 Jun 2010 09:31:57 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Wed, 16 Jun 2010 07:45:34 -0500, John Fields
jfields@austininstruments.com> wrote:

On Tue, 15 Jun 2010 19:42:04 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Tue, 15 Jun 2010 13:44:39 -0500, John Fields
jfields@austininstruments.com> wrote:

On Tue, 15 Jun 2010 07:00:03 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Tue, 15 Jun 2010 00:31:35 -0500, John Fields
jfields@austininstruments.com> wrote:

On Mon, 14 Jun 2010 08:25:57 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Mon, 14 Jun 2010 07:23:14 -0700, Archimedes' Lever
OneBigLever@InfiniteSeries.Org> wrote:

On Mon, 14 Jun 2010 07:19:37 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

Fluid of course. Few people ever measure force. And most liquids used
in everydat life have a s.g. near 1, so an ounce of tabasco is
unambiguous.

Hundreds, even thousands of folks measure force every day, and many of
those use ounces in their scales of measure. Many use Newtons.


Of course hundreds, maybe even thousands of people measure force every
day. But there are 300 million people in the USA. Most people never
measure force; they do measure weight, or mass actually.

---
Since weight is mass multiplied by the acceleration of gravity and
most people use scales instead of beam balances and calibrated
reference masses to do the measurement, they measure weight, not mass.

http://en.wikipedia.org/wiki/Weighing_scale



Most people in the world use SI units, and they weigh things in
kilograms. A kg is a unit of mass.

Whether they use springs or balance beams or load cells, the reported
result is mass. kg, not newtons.

---
Sorry, but no.

The result of the measurement is caused by a force acting on a mass,
the product of which is called a "newton" if the mass is 1kg and the
force is the attraction due to gravity, 9.8m/s˛.

Entirely wrong:

http://en.wikipedia.org/wiki/Newton_%28unit%29

---
Yup.

I got the mass wrong, (it should be about 102 grams) but the fact
still remains that what a scale does is measure weight, not mass.

OK, today's puzzler:

Suppose I weigh myself at home, using my ordinary spring-based
bathroom scale. Home is 365 feet above sea level. Now I drive to
Truckee; it takes about 3 hours if I push it, 80+ MPH except for the
speed trap at Clipper Gap. When I arrive I use the same scale to weigh
myself, now at 6400 feet. Latitude is about the same.

1. About how much has my measured weight changed due to the change of
G with altitude?

2. Is this significant to the measurement?

Rules: you have one minute to deliver an answer. Use no paper, pencils
or equivalent, calculators, computers, books, or any external
assistance or references of any kind. Keep your eyes closed. Do it
entirely in your head.

Extra credit, one more minute:

3. Is the position of the moon significant to the measurement?

---
That's too much like work; I decline.

Around our shop, we do stuff like this all the time, calculate corner
frequencies or power dissipations or noise levels or loop stabilities,
in our heads, in seconds, standing in a corridor or at a whiteboard.
Rough calculations like this should be second nature to engineers.

See Williams, 1991, p 295, or google lightning empiricism

There's a Feynman story somewhere about this, too.

John

 

[Archimedes' Lever]

On Wed, 16 Jun 2010 10:17:37 -0700 (PDT), ihis groE <mahdert@gmail.com>
wrote:

Yes folks, the US will never go metric because we stuck our foot in
our mouths.


Why the U.S. should use the metric system.. See link below

http://www.wimp.com/metricsystem/

Most of us that have a modicum of sense DO use it, so you are the one
that it decades behind. I have been using it for decades.

 

[Archimedes' Lever]

On Wed, 16 Jun 2010 12:23:29 -0500, John Fields
<jfields@austininstruments.com> wrote:

On Wed, 16 Jun 2010 09:31:57 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Wed, 16 Jun 2010 07:45:34 -0500, John Fields
jfields@austininstruments.com> wrote:

On Tue, 15 Jun 2010 19:42:04 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Tue, 15 Jun 2010 13:44:39 -0500, John Fields
jfields@austininstruments.com> wrote:

On Tue, 15 Jun 2010 07:00:03 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Tue, 15 Jun 2010 00:31:35 -0500, John Fields
jfields@austininstruments.com> wrote:

On Mon, 14 Jun 2010 08:25:57 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Mon, 14 Jun 2010 07:23:14 -0700, Archimedes' Lever
OneBigLever@InfiniteSeries.Org> wrote:

On Mon, 14 Jun 2010 07:19:37 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

Fluid of course. Few people ever measure force. And most liquids used
in everydat life have a s.g. near 1, so an ounce of tabasco is
unambiguous.

Hundreds, even thousands of folks measure force every day, and many of
those use ounces in their scales of measure. Many use Newtons.


Of course hundreds, maybe even thousands of people measure force every
day. But there are 300 million people in the USA. Most people never
measure force; they do measure weight, or mass actually.

---
Since weight is mass multiplied by the acceleration of gravity and
most people use scales instead of beam balances and calibrated
reference masses to do the measurement, they measure weight, not mass.

http://en.wikipedia.org/wiki/Weighing_scale



Most people in the world use SI units, and they weigh things in
kilograms. A kg is a unit of mass.

Whether they use springs or balance beams or load cells, the reported
result is mass. kg, not newtons.

---
Sorry, but no.

The result of the measurement is caused by a force acting on a mass,
the product of which is called a "newton" if the mass is 1kg and the
force is the attraction due to gravity, 9.8m/s˛.

Entirely wrong:

http://en.wikipedia.org/wiki/Newton_%28unit%29

---
Yup.

I got the mass wrong, (it should be about 102 grams) but the fact
still remains that what a scale does is measure weight, not mass.

OK, today's puzzler:

Suppose I weigh myself at home, using my ordinary spring-based
bathroom scale. Home is 365 feet above sea level. Now I drive to
Truckee; it takes about 3 hours if I push it, 80+ MPH except for the
speed trap at Clipper Gap. When I arrive I use the same scale to weigh
myself, now at 6400 feet. Latitude is about the same.

1. About how much has my measured weight changed due to the change of
G with altitude?

2. Is this significant to the measurement?

Rules: you have one minute to deliver an answer. Use no paper, pencils
or equivalent, calculators, computers, books, or any external
assistance or references of any kind. Keep your eyes closed. Do it
entirely in your head.

Extra credit, one more minute:

3. Is the position of the moon significant to the measurement?

---
That's too much like work; I decline.

I did it. Just the way he said, and I even did it before I read his
rules.

He may not like the answer though.

 

[Archimedes' Lever]

On Wed, 16 Jun 2010 10:25:36 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Wed, 16 Jun 2010 10:02:17 -0700, Archimedes' Lever
OneBigLever@InfiniteSeries.Org> wrote:

On Wed, 16 Jun 2010 09:31:57 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

1. About how much has my measured weight changed due to the change of
G with altitude?

Depends on the scale, and its calibrated range of operation, and the
atmospheric pressure.

The scale I gave you a picture of (link) shows you exactly what the
difference is in G.

Time's up. You blew it.

John

Sad thing is that you have obviously blown something else that most
real men possess. Something that it is now clear that you'll never
recover from. In that area, you are simply irrecoverably 'hard wired
dumb'.

 

[Tim Watts]

On Wed, 16 Jun 2010 07:35:02 -0700, Fred Abse
<excretatauris@invalid.invalid> wibbled:

On Mon, 14 Jun 2010 22:01:51 +0000, Tim Watts wrote:

SI rules for science, imperial rules for everyday living. Except
carpentry - I hate fractions!

You would rather multiply a piece of timber by 0.5, than cut it in half?

;-)

It's the 1/8ths, and 1/16ths that get me, not the halves

BTW - did you know most weed (cannabis) dealing here is still Imperial,
so I've been told *cough*.

Apparently people still go and buy "a eighth" (of an ounce) and not some
number of mg.



--
Tim Watts

Managers, politicians and environmentalists: Nature's carbon buffer.

 

[Archimedes' Lever]

On Wed, 16 Jun 2010 10:26:05 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Wed, 16 Jun 2010 10:05:09 -0700, Archimedes' Lever
OneBigLever@InfiniteSeries.Org> wrote:

On Wed, 16 Jun 2010 09:31:57 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

2. Is this significant to the measurement?


If one is measuring mass, yes. It matters.

If one is measuring "weight" it is ALWAYS relative to the calibration
position and circumstance.

If those are changed, the weight reading changes, even though the
weight hasn't.

If the operator is aware of this, and is aware of the degree of
precision or lack thereof that instills into this method of
determination, he can reasonably be expected to know how reliable any
reading from a simple weight scale provides.

Word salad. Do the math.

John

Your rules said no math, idiot.

An reasonably smart man would know which way the error moves and
approximately by how much, using the calibration location as a reference,
which is all that matters with a weight scale. 100% oblivious folks like
you simply rely on the reading and look for a date on the cal sticker,
and think your reading is accurate. Oblivious folks like you do not
consider error at that level. Oblivious folks like you glance over a
concept or rule in a book, and then think that you are an expert on it
from that point forward, when in reality you have little or no grasp of
it whatsoever.

Like you and the solvent vapor cloud thing, where you think that the PCB
being cleaned will rise in temp too fast to let the VAPOR do the
cleaning, like the design calls for. NO. You, in your infinite wisdom,
think that the assembly equalizes in temp with the cloud and no cleaning
would take place. You are an idiot.

Like you and the torque thing.

Like you and the Spice attitude thing

Like you and the scale thing.

I know where all my test gear got calibrated, and which are affected by
environmental factors. Do you?

I think I could do the math on that answer.

 

[Tim Watts]

On Wed, 16 Jun 2010 11:17:43 -0500, John Fields
<jfields@austininstruments.com> wibbled:

Does your scale report your weight in newtons?

---
No, it reports my weight in pounds, which is wrong because a pound is a
measure of mass, not of weight.

http://en.wikipedia.org/wiki/Pound_(mass)#Definitions



--
Tim Watts

Managers, politicians and environmentalists: Nature's carbon buffer.

 

[Archimedes' Lever]

On Wed, 16 Jun 2010 10:27:56 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Wed, 16 Jun 2010 10:10:27 -0700, Archimedes' Lever
OneBigLever@InfiniteSeries.Org> wrote:

On Wed, 16 Jun 2010 09:31:57 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

3. Is the position of the moon significant to the measurement?

John

Yes.

The correct answer must be "no", since you're AlwaysWrong.



Again, if the operator wants precision, he needs to measure mass, and
use a balance to do so. If one only wants the precision reliance that a
weight scale provides, one cannot expect, reasonably or otherwise, that
the reading given on the scale can be considered an "exact" reading.

With the degree of error in mind, a reasonable operator would know that
it is pretty close, but would still be aware that it was measured against
the Earth's gravity, and not truly as compared against a reference mass
using a device that is not bound by Earths gravity to operate.

So, the Moon changes Earth's gravitational field in such a way that
a reading taken (with a weight scale) at any given point on Earth will
vary depending on where the Moon is at with reference to where the scale
is at.

Words, words, words. The answer would be numbers.

Your smart move would have been to ignore my post.

John

You asked a yes or no question, idiot. I gave more of an answer than
you even asked for.

Your common sense number is near zero.

 

[Archimedes' Lever]

On Wed, 16 Jun 2010 10:40:57 -0700, John Larkin
<jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Wed, 16 Jun 2010 12:23:29 -0500, John Fields
jfields@austininstruments.com> wrote:

On Wed, 16 Jun 2010 09:31:57 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Wed, 16 Jun 2010 07:45:34 -0500, John Fields
jfields@austininstruments.com> wrote:

On Tue, 15 Jun 2010 19:42:04 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Tue, 15 Jun 2010 13:44:39 -0500, John Fields
jfields@austininstruments.com> wrote:

On Tue, 15 Jun 2010 07:00:03 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Tue, 15 Jun 2010 00:31:35 -0500, John Fields
jfields@austininstruments.com> wrote:

On Mon, 14 Jun 2010 08:25:57 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Mon, 14 Jun 2010 07:23:14 -0700, Archimedes' Lever
OneBigLever@InfiniteSeries.Org> wrote:

On Mon, 14 Jun 2010 07:19:37 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

Fluid of course. Few people ever measure force. And most liquids used
in everydat life have a s.g. near 1, so an ounce of tabasco is
unambiguous.

Hundreds, even thousands of folks measure force every day, and many of
those use ounces in their scales of measure. Many use Newtons.


Of course hundreds, maybe even thousands of people measure force every
day. But there are 300 million people in the USA. Most people never
measure force; they do measure weight, or mass actually.

---
Since weight is mass multiplied by the acceleration of gravity and
most people use scales instead of beam balances and calibrated
reference masses to do the measurement, they measure weight, not mass.

http://en.wikipedia.org/wiki/Weighing_scale



Most people in the world use SI units, and they weigh things in
kilograms. A kg is a unit of mass.

Whether they use springs or balance beams or load cells, the reported
result is mass. kg, not newtons.

---
Sorry, but no.

The result of the measurement is caused by a force acting on a mass,
the product of which is called a "newton" if the mass is 1kg and the
force is the attraction due to gravity, 9.8m/s˛.

Entirely wrong:

http://en.wikipedia.org/wiki/Newton_%28unit%29

---
Yup.

I got the mass wrong, (it should be about 102 grams) but the fact
still remains that what a scale does is measure weight, not mass.

OK, today's puzzler:

Suppose I weigh myself at home, using my ordinary spring-based
bathroom scale. Home is 365 feet above sea level. Now I drive to
Truckee; it takes about 3 hours if I push it, 80+ MPH except for the
speed trap at Clipper Gap. When I arrive I use the same scale to weigh
myself, now at 6400 feet. Latitude is about the same.

1. About how much has my measured weight changed due to the change of
G with altitude?

2. Is this significant to the measurement?

Rules: you have one minute to deliver an answer. Use no paper, pencils
or equivalent, calculators, computers, books, or any external
assistance or references of any kind. Keep your eyes closed. Do it
entirely in your head.

Extra credit, one more minute:

3. Is the position of the moon significant to the measurement?

---
That's too much like work; I decline.

Around our shop, we do stuff like this all the time, calculate corner
frequencies or power dissipations or noise levels or loop stabilities,
in our heads, in seconds, standing in a corridor or at a whiteboard.
Rough calculations like this should be second nature to engineers.

See Williams, 1991, p 295, or google lightning empiricism

There's a Feynman story somewhere about this, too.

John

You were given the answers, John. It simply comes down to the fact that
you are NOT a 'reasonable man', much less a 'reasonably intelligent man'.

 

[Archimedes' Lever]

On Wed, 16 Jun 2010 11:05:15 -0700 (PDT), George Herold
<gherold@teachspin.com> wrote:

Cool, I have to scribble numbers on the paper though. 6400 feet is
about 2000m, the Earth is about 6E6 m in radius, Since we only want a
small change I can ignore the r^2 stuff and just multiple the ratio by
2. something like 4 parts out of 6,000. much smaller than the
divisions on your scale.

No you cannot. What makes you think that G decreases (or
increases)linearly?

 

[John Larkin]

On Wed, 16 Jun 2010 11:30:26 -0700, Archimedes' Lever
<OneBigLever@InfiniteSeries.Org> wrote:

On Wed, 16 Jun 2010 10:40:57 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Wed, 16 Jun 2010 12:23:29 -0500, John Fields
jfields@austininstruments.com> wrote:

On Wed, 16 Jun 2010 09:31:57 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Wed, 16 Jun 2010 07:45:34 -0500, John Fields
jfields@austininstruments.com> wrote:

On Tue, 15 Jun 2010 19:42:04 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Tue, 15 Jun 2010 13:44:39 -0500, John Fields
jfields@austininstruments.com> wrote:

On Tue, 15 Jun 2010 07:00:03 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Tue, 15 Jun 2010 00:31:35 -0500, John Fields
jfields@austininstruments.com> wrote:

On Mon, 14 Jun 2010 08:25:57 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

On Mon, 14 Jun 2010 07:23:14 -0700, Archimedes' Lever
OneBigLever@InfiniteSeries.Org> wrote:

On Mon, 14 Jun 2010 07:19:37 -0700, John Larkin
jjlarkin@highNOTlandTHIStechnologyPART.com> wrote:

Fluid of course. Few people ever measure force. And most liquids used
in everydat life have a s.g. near 1, so an ounce of tabasco is
unambiguous.

Hundreds, even thousands of folks measure force every day, and many of
those use ounces in their scales of measure. Many use Newtons.


Of course hundreds, maybe even thousands of people measure force every
day. But there are 300 million people in the USA. Most people never
measure force; they do measure weight, or mass actually.

---
Since weight is mass multiplied by the acceleration of gravity and
most people use scales instead of beam balances and calibrated
reference masses to do the measurement, they measure weight, not mass.

http://en.wikipedia.org/wiki/Weighing_scale



Most people in the world use SI units, and they weigh things in
kilograms. A kg is a unit of mass.

Whether they use springs or balance beams or load cells, the reported
result is mass. kg, not newtons.

---
Sorry, but no.

The result of the measurement is caused by a force acting on a mass,
the product of which is called a "newton" if the mass is 1kg and the
force is the attraction due to gravity, 9.8m/s˛.

Entirely wrong:

http://en.wikipedia.org/wiki/Newton_%28unit%29

---
Yup.

I got the mass wrong, (it should be about 102 grams) but the fact
still remains that what a scale does is measure weight, not mass.

OK, today's puzzler:

Suppose I weigh myself at home, using my ordinary spring-based
bathroom scale. Home is 365 feet above sea level. Now I drive to
Truckee; it takes about 3 hours if I push it, 80+ MPH except for the
speed trap at Clipper Gap. When I arrive I use the same scale to weigh
myself, now at 6400 feet. Latitude is about the same.

1. About how much has my measured weight changed due to the change of
G with altitude?

2. Is this significant to the measurement?

Rules: you have one minute to deliver an answer. Use no paper, pencils
or equivalent, calculators, computers, books, or any external
assistance or references of any kind. Keep your eyes closed. Do it
entirely in your head.

Extra credit, one more minute:

3. Is the position of the moon significant to the measurement?

---
That's too much like work; I decline.

Around our shop, we do stuff like this all the time, calculate corner
frequencies or power dissipations or noise levels or loop stabilities,
in our heads, in seconds, standing in a corridor or at a whiteboard.
Rough calculations like this should be second nature to engineers.

See Williams, 1991, p 295, or google lightning empiricism

There's a Feynman story somewhere about this, too.

John


You were given the answers, John.

No, I invented the puzzle, and the answer, in the shower this morning.
It took less than a minute. If anybody knows elementary physics, it's
simple.

John