Snorkel and other stuff

[(RIP) PLANK]

totally different ball game with water.

forget traction and all ground rules, with water air = buoyancy / floating and that is the one thing you dont want. especially in rivers so the least air is best. remembering you still have to continue your drive later

if your floating you have no drive or control
see recent post on ozz floods and they didnt have 33" tyres on

but the pressure in the tyres should make no difference, a greater volume of air would give more boyancy, but the same volume at higher pressure would have the same boyancy :nenau It might feel better letting the air out, but it can't make much, if any, difference. Bigger tyres would as they would have a greater volume of air.

 

[makeitfit]

but the pressure in the tyres should make no difference, a greater volume of air would give more boyancy, but the same volume at higher pressure would have the same boyancy :nenau It might feel better letting the air out, but it can't make much, if any, difference. Bigger tyres would as they would have a greater volume of air.

I think the term you're looking for is "displacement" archimedes (however you spell it :augie)

 

[extreme-4x4]

remember top gear when the inflated a flat tyre off another one and the both had air but pressured equally

 

[(RIP) PLANK]

I think the term you're looking for is "displacement" archimedes (however you spell it :augie)

no, objects that sink displace! we are talking abut bouyancy :doh :thumb2

 

[makeitfit]

no, objects that sink displace! we are talking abut bouyancy :doh :thumb2

NO:doh
Ships "displace" to stay afloat
An object in a fluid experiences an upward force equal to the weight of the fluid displaced by the object.
The tryes displace water and so help float your boat, er I mean truck:thumbs

 

[(RIP) PLANK]

NO:doh
Ships "displace" to stay afloat
An object in a fluid experiences an upward force equal to the weight of the fluid displaced by the object.
The tryes displace water and so help float your boat, er I mean truck:thumbs

yes but the portion below the water line ( the sunken bit) displaces!

Hopefully with your tyres they wil be under water regardless of size or pressure!

Imagine your ship, if you load it up with empty air cylinders and measure the displacement, then load it up with cylinders full of vompresed air and measure again. The wight of the compressed air will weigh it down. Surley this is the same wiht a tyre, I'm not suggesting more air will make it heavier, but i shouldn't make it float any more, unless of course it increases it volume by blowing it up like a baloon :naughty

 

[(RIP) PLANK]

remember top gear when the inflated a flat tyre off another one and the both had air but pressured equally

no mate i didn't see that, and to be fair i don't understand.

are we saying if you have one tyre with 0 PSI (technically imposssible as it must, in real terms) alway have at least 14.7 psi even when not mounted on a rim.

and another with 30 psi, joi the vlaves together they will equal at 15?

If so, i don't see the relationship to this and bouyancy / displacement?

 

[extreme-4x4]

a glass bottle full of water sinks. the same bottle full of air remains at the surface

same displacement area

 

[makeitfit]

yes but the portion below the water line ( the sunken bit) displaces!

Well obviously, that is the defenition, innit?:augie
I agree about the pressure and that just pointing out the theory is all. I think we're on the same page but you're reading it upside down :lol:lol

 

[(RIP) PLANK]

a glass bottle full of water sinks. the same bottle full of air remains at the surface

yes, you have a point!

lets say it has a volume of 1 (at noormal open pressure)

and you compress 1 + 1 of air in it (approx 29.4 psi)

I think tha it wouldn't float any higher, in fact it may sink lower!

So if your tyre remains the same size, unless you fill it with water, it will not float any higher or lower.


It would be interesting to do this as an experiment.

inflate a tyre to say 20 pis (34.7 in real terms) and wieght it until it just sinks below the surface.

The add more air and see if it floats enough to overcome the wieight.

 

[jace]

bit like the melting icebergs and sea levels rising all green bull to get tax out us!

 

[extreme-4x4]

yes, you have a point!

lets say it has a volume of 1 (at noormal open pressure)

and you compress 1 + 1 of air in it (approx 29.4 psi)

I think tha it wouldn't float any higher, in fact it may sink lower!

So if your tyre remains the same size, unless you fill it with water, it will not float any higher or lower.


It would be interesting to do this as an experiment.

inflate a tyre to say 20 pis (34.7 in real terms) and wieght it until it just sinks below the surface.

The add more air and see if it floats enough to overcome the wieight.

that sounds like a plan, for tomorrows bath time.

another thought you might want to consider . if your tyre is inflated at 30 psi and you want it at 60 psi, the tyre is not going to grow massively. but your there hours shoving more air in... i have not found a way of raising the psi without adding air or another liquid/gas....... unless you add weight to the truck but you would need a lot of weight

 

[makeitfit]

a glass bottle full of water sinks. the same bottle full of air remains at the surface

same displacement area

Ay but if you put that bottle of water in say some treacle it would float
What ever you put in the water , it's the weight of that water "displaced" that is the float weight:thumbs simples.
The denser the liquid you put your bottle in the higher it will float.:thumbs

 

[(RIP) PLANK]

that sounds like a plan, for tomorrows bath time.

another thought you might want to consider . if your tyre is inflated at 30 psi and you want it at 60 psi, the tyre is not going to grow massively. but your there hours shoving more air in... i have not found a way of raising the psi without adding air or another liquid/gas....... unless you add weight to the truck but you would need a lot of weight

that's my point, the volume of the tyre (overall size) remains , more-or-less, the same, so it displaces the same amount of water and creates the same bouyancy regardless of pressure. To increase pressure you have to increase the amount of litres of air in they tyre which would make it weigh more and hence give less bouyancy.


confusing i know, but very interesting - if your a geek like me i suppose :question

 

[extreme-4x4]

you realize rick will be along in a min to shoot us all down in flames

 

[(RIP) PLANK]

you realize rick will be along in a min to shoot us all down in flames

maybe, ,aybe not it's suprising how many peple get this stuff wrong. I may be wrong, but i'm pretty sure as i studied the ins and outs of compressed air as young engineer many moons ago.

The air around us is at 14.7 psi (1 bar) with slight atmospheric variation, so when your pressure guage reads 10psi it is relative - i.e 10 psi more than the 14.7 psi it allready had before you started inflating it, and that is pressing against the tyre from outside at all times.

A bit like the 'potential diference' in voltage calculations i suppose.

I am itching to have a go at inflating a tyre to different pressures and seeing how differently it floats now :lol

 

[Fez_uk]

I've got a coke bottle with a shrader bike valve attached. I will see what it does tomorrow.

 

[extreme-4x4]

maybe, ,aybe not it's suprising how many peple get this stuff wrong. I may be wrong, but i'm pretty sure as i studied the ins and outs of compressed air as young engineer many moons ago.

The air around us is at 14.7 psi (1 bar) with slight atmospheric variation, so when your pressure guage reads 10psi it is relative - i.e 10 psi more than the 14.7 psi it allready had before you started inflating it, and that is pressing against the tyre from outside at all times.

A bit like the 'potential diference' in voltage calculations i suppose.

I am itching to have a go at inflating a tyre to different pressures and seeing how differently it floats now :lol

not on my bath you wont:naughty:naughty:naughty

 

[(RIP) PLANK]

as long as you measure the circimferance to make sure it doesn't get significantly bigger, it should do the same job.

it's a dirty job but some one has to do it, well volunteered :thumb2

 

[makeitfit]

I'm trying to remember my college stuff too:dohbut I do believe it's to do with Pressure and Mass really. Not bouyancy and weight.
I'll be back:augie