Recent content by SteveA001

That's roughly what I get using your numbers. Then I think you add 'Partial pressure of water vapor in final state' to 'Partial pressure of air in final state' to get 'Total pressure in the quenched container', making 22800 Pa, or 22.7 % of atmospheric pressure. An Excel sheet is attached, if...

Nice work. I've run some numbers through it, in Excel. Using the same temperatures as before (71C to 20C) for a flask 98% full of water and then 2% full, producing answers of 30% of atmospheric pressure and 60% (the second one being same as before, when not taking condensation into account)...

Oh, that would be a small effect then. Thanks for your help. Now that the answer is quantified, lots of everyday observations can be explained. For example why vacuum flasks and hot water bottles have hard screw tops. I am also testing a preheated vacuum flask with large airspace and little...

Sneaky, p1/t1= p2/t2. So if the initial temperature were 95C the vacuum would be 15% of atmospheric pressure. And at 100 C it would be 1 atmosphere of vacuum. But did we use the specific volume of water vapor (4.84 kg/m^3) and the mass calculated earlier?

~2350 Pa I'm still coming to grips with the concept of partial pressures, having only seen it in relation to parts of air rather than to the entire air. Based on the earlier example partialPressureOfAirInHeadspace = totalPressure - 2350? Is it something that can be found from lookup tables...

D'oh, I googled rather than calculating. I found a table online(https://www.thermexcel.com/english/tables/vap_eau.htm), added an exponential trend line in Excel and got this formula: Specific volume (steam) = 1.6888*(AbsolutePressureInBar)^-0.942. This agrees with your value for 0.327 bar. I...

Ah, yes. I have just tried it with a plastic bottle and it did indeed deform as it cooled, indicating a pressure drop as you say. It appears I was distracted by my vacuum flask performance. Strange that it doesn't appear to pop or offer resistance when opened. My original inquiry, before was the...

Ah, yes. I have just tried it with a plastic bottle and it did indeed deform as it cooled, indicating a pressure drop, as you say. It appears I was distracted by my vacuum flask, strange that it doesn't appear to pop or offer resistance when opened when cooled. My original interest was in the...

If a bottle is partially filled with hot water and sealed, together what some air, what happens to the pressure inside the bottle as it cools to room temperature? Assumptions: The temperature of the air in the bottle will initially be about the hot water temperature as the bottle is first...

Ok, multiplying by 3 or so it is, for rough purposes. Thanks for your help.

I just wanted to know the number of protons hitting a 1 m^2 surface. Is the solid angle of such a 'detector', which is facing directly towards the sun, 2 PI steradians? If so, the answer I want is the particle number they give for proton flux (cm-2 s-1 sr-1) should be multiplied by 2 PI and...

I meant proton flux, sorry if my question is in the wrong section. Why is proton flux given in units of particles cm-2 s-1 sr-1 and not just as particles cm-2 s-1. [A search on "solar flare proton flux" returns pages using those units as the top search results]. Given those tricky units, what is...

Hi, I wanted to find the number of protons striking a surface area during a solar event and the units provided are: #/(cm^2 s sr). Say I have a 1 m^2 surface area directly facing the sun, how do I use those units to discover the number of protons/s. What is the value of the solid angle to...