Hi, this morning in the school lab we did experiments about pressure and I've some questions., could you help me? thanks!
If I fill a glass with water the atmospherical pressure press on water on top of glass because it is in contact with air, but does atmospherical pressure press on the water on bottom of glass ?
so to calculate pressure I must include the atmosperical pressure on Stevino's formula?
If mustn't, how can atm. pressure pass through the glass material and why if there is no air on the bottom?
When i pump out air from a bell jar do I progressively reduce the atmospherical pressure inside bell?
what happen if pumped out ALL the air inside (so there is no atmosperical pressure) i continue pumping out?
Ancient greek used to weigh a container full of air then squeeze it and weigh it again. So why if squeezing it the air go out the weight is the same in both ?
P = p0 + d * g * h
The Attempt at a Solution
In my opinion in the first problem atmospheric pressure must be considerate, in the other two i've no idea.