Strangest Tire Question EVERRR...

Steve W.

No difference, even though the atmosphere, and the human, are not inside
a container, as with the air in a tire?

On 5/4/2020 12:22 PM, Steve W. wrote:
> wrote:
>> Xeno, Arlen:
>>
>>
>> My postulation is more a matter of wording:
>> We do not put "33 pounds of air" in a given tire.Â* We put 33 pounds
>> PER SQUARE INCH in
>> that tire.Â* Ergo, that volume of air is applying 33lbs of force to
>> EVERY SQUARE INCH of the inside of that tire & rim face combination.
>>
>
> Correct, it applies 33 PSI of force to every square inch. However that
> is the total force per square inch that the air applies. You cannot add
> each inch up and say that number is the total pressure applied.
>
> It is no different than atmospheric pressure which is around 14.696 PSI.
> Using your version of physics every human being would be crushed to
> death by that pressure if you consider the average human male has 22.173
> square feet of surface area.
>
> https://chem.libretexts.org/Bookshel...ts_Measurement

Obviously. Not worth discussing with those who mistake
and interchangeably use the terms force and pressure.
Don't get them started on energy and power.

In response to what Heron > wrote :

> Obviously. Not worth discussing with those who mistake
> and interchangeably use the terms force and pressure.
> Don't get them started on energy and power.

While...
o Force = pressure per unit area

What always confuses me are things like centrifugal versus centripedal
forces (yes, I know, frames of reference stuff)...

There's a good graph here...
<http://hyperphysics.phy-astr.gsu.edu/hbase/force.html#defor>

Energy/power/work often confuse me when engaged in casual conversation...
o <http://hyperphysics.phy-astr.gsu.edu/hbase/work.html>

Work is the result of a force and movement in the direction of that force:
o A force of 20 newtons pushing an object 5 meters in the direction of the
force does 100 joules of work.

Energy is the capacity for doing work:
o To do 100 joules of work, you must expend 100 joules of energy.

Power is the rate of doing work (or of using energy)
o If you do 100 joules of work in one second (using 100 joules of energy),
the power is 100 watts.

In casual speech, this gets confusing for me, where when I was in graduate
school, it was better ingrained, but I lost that advantage decades ago.
--
Usenet is so much more valuable, and pleasant, when people share solutions.

Xeno wrote:
> On 4/5/20 3:28 am, Paul in Houston TX wrote:
>> wrote:
>>> Strangest Tire Question EVERRR...
>>>
>>> Has anyone ever calculated or estimated the area, in square
>>> inches/square cm, of the *surface of the inside* of a tire?
>>>
>>> Does at least an average exist out there, for broad categories:
>>> passenger car, SUV-light truck, and commercial truck?
>>>
>>> Just curious, Thanks!
>>
>> Entering footprint into the argument.
>> My car's GVW is 3800 lbs so each tire supports 950 lbs (ideally).
>> If a my tire has a footprint of 6"x6" = 36" sq, and if each sq in has
>> a pressure of 36 psi, then the psi total of the footprint is 1296 lbs.
>> Oddly enough my car tire's max load rating is 1295 lbs.Â* Push on it
>> with an area and it will push back equally.
>> The rest of the tire area is at 36 psi and is irrelevant since it does
>> not support anything.
>
> Lower the tyre pressure and see what happens to the sidewalls.

Good point!

On 5/5/20 1:32 am, wrote:
> Xeno, Arlen:
>
>
> My postulation is more a matter of wording:
>
> We do not put "33 pounds of air" in a given tire. We put 33 pounds PER SQUARE INCH in
> that tire. Ergo, that volume of air is applying 33lbs of force to EVERY SQUARE INCH of
> the inside of that tire & rim face combination.
>
Nobody, least of all me, is disputing that!

--

Xeno


Nothing astonishes Noddy so much as common sense and plain dealing.
(with apologies to Ralph Waldo Emerson)

On 5/5/20 7:02 am, Arlen Holder wrote:
> In response to what Heron > wrote :
>
>> Obviously. Not worth discussing with those who mistake
>> and interchangeably use the terms force and pressure.
>> Don't get them started on energy and power.
>
> While... o Force = pressure per unit area
>
> What always confuses me are things like centrifugal versus centripedal
> forces (yes, I know, frames of reference stuff)...
> There's a good graph here...
> <http://hyperphysics.phy-astr.gsu.edu/hbase/force.html#defor>
>
> Energy/power/work often confuse me when engaged in casual conversation...
> o <http://hyperphysics.phy-astr.gsu.edu/hbase/work.html>
>
> Work is the result of a force and movement in the direction of that force:
> o A force of 20 newtons pushing an object 5 meters in the direction of the
> force does 100 joules of work.
> Energy is the capacity for doing work:
> o To do 100 joules of work, you must expend 100 joules of energy.
> Power is the rate of doing work (or of using energy)
> o If you do 100 joules of work in one second (using 100 joules of energy),
> the power is 100 watts.
> In casual speech, this gets confusing for me, where when I was in graduate
> school, it was better ingrained, but I lost that advantage decades ago.

Centrifugal force is a convenient fiction.

--

Xeno


Nothing astonishes Noddy so much as common sense and plain dealing.
(with apologies to Ralph Waldo Emerson)

In response to what Xeno > wrote :

> Centrifugal force is a convenient fiction.

Indeed.
o At least from one point of view.