All Questions
Tagged with everyday-life pressure
101
questions
0
votes
1
answer
123
views
Pouring liquid out of a bottle smoothly
Can one calculate the vacuum pressure created inside a bottle when pouring liquid from it?
Glass bottle
38mm diameter orifice
- 1
5
votes
1
answer
338
views
How does sharpening a pencil make it darker?
Why does a sharp pencil write better than a blunt one?
Note that the force applied on each case is identical.
- 12.5k
0
votes
1
answer
697
views
Why does a fountain pen soak ink automatically at times?
I've had a rather interesting fascination with fountain pens. The mechanism is a thing of beauty, but my attention was recently caught by a rather insignificant phenomenon which I've used a lot in my ...
- 1,630
2
votes
5
answers
1k
views
Woodworking clamps, does force add up?
I was watching a woodworking video about glue, and the guy was clamping two pieces of wood together using a total of 8 clamps. He argued that by doing so he would apply 8 times the maximum force of ...
- 123
0
votes
1
answer
123
views
is boiling point of the gas cause cooling in expansion process of refrigeration?
I have a doubt about expansion process.
Some people say it's an adiabatic expansion, but other say it's something related to the nozzle.
What is the actual cause for cooling in expansion process?
...
- 191
1
vote
1
answer
1k
views
Why does water not leak from the bag?
In the picture, the plastic bag is filled with water. The sharpened pencil penetrates through the bag. However, there is no leakage.
Could you please explain why this happens?
-3
votes
1
answer
724
views
The Mystery of the Starbucks coffee lid [closed]
If you look at a (white, opaque) Starbucks coffee lid (and the lids of many other coffee brands as well) you will see in addition to the obvious sip hole, one or more tiny perforated holes on the top ...
- 2,637
-2
votes
1
answer
4k
views
Physics/forces involved when separating two 5 gallon buckets
So a friend jokingly said "there's no force in the universe stronger than two 5 gallon buckets that are stick together." And I thought that this has to have a wonderfully complex and scientific ...
-1
votes
3
answers
114
views
Why is there less oxygen in a pressurised plane that is flying?
Children who have temporary lung problems like asthma attacks have to go on oxygen to heal. (At a hospital.) Immediately after a health incident they can’t go on an aeroplane because there is ...
- 861
1
vote
3
answers
273
views
Is a well inflated tire less prone than a deflated tire to flatten due to a sharp object? [closed]
When I bought my bike, I've been told that I should make sure the tires are well inflated because this reduces the risks of having a flat tire when rolling over sharp objects, and that it was easy to ...
83
votes
4
answers
8k
views
What causes the water in this fountain to reverse direction?
In a children's museum, I ran across this fountain. You can adjust the flow rate with a valve, visible at the bottom. At low flow rates, the sheet of water does more or less what you'd expect: it ...
- 9,765
1
vote
1
answer
221
views
Holding one's breath while scuba diving
Recently when I went scuba diving, the instructor told me that it would be extremely fatal to a scuba diver to hold his breath during the dive. I searched up on the internet and came across Boyle's ...
- 3,745
-2
votes
1
answer
80
views
Why will crushing a water bottles keep the water in fizzy condition? [duplicate]
Everybody is talking only about CO2.
- 1
0
votes
0
answers
419
views
What's the difference between compression by a gas/liquid or by a solid?
Atmospheric pressure is about $1atm$, that is $\approx 10^5 N/m^2$, that is, if $g = 9.8m/s^2$ we get a weight of $\approx 10.339 tons/m^2$. And yet, nobody feels like carrying 10 tons of stuff above ...
- 3,274
4
votes
1
answer
1k
views
Boiling of Water
I studied in textbooks that the boiling point of water is the temperature at which the vapor pressure is equal to the atmospheric presssure. My doubt is since the vapor mixes with atmosphere, how can ...
- 63