All Questions
Tagged with everyday-life pressure
101
questions
2
votes
1
answer
96
views
Why does the bottle create vacuum inside if left closed?
I'm not 100% it's correct but it has happened to me a lot of times, I always close down a bottle normally with not too much tightness, with no liquid inside, and after a day it always is so hard to ...
- 69
6
votes
1
answer
1k
views
How does a bottle pour its contents?
Consider this soy sauce bottle:
The cap has two holes that are directly opposite to one another. Covering one hole, I find the soy sauce almost doesn't pour at all.
However, consider a bottle with a ...
- 318
3
votes
2
answers
125
views
Why do wet napkins stick to mirrors or glass?
Take a dry piece of napkin & put it against a mirror ==> it falls down.
Dab it in water, oil, or alcohol ==> it now sticks / adheres to the mirror.
How can we explain this in physics terms? ...
- 196
2
votes
1
answer
452
views
Pressure cooker becomes pressurized again after closing and opening?
While cooking food in my pressure cooker today, I pulled the whistle using my spatula to let the steam off before I opened it to check on how well cooked the food was. Before, I opened the pressure ...
- 7,980
43
votes
10
answers
5k
views
When a cork is pulled out of a wine bottle, why does the inner end often expand more than the outer end?
When I pull a cork out of a wine bottle, it usually expands slightly in circumference. This makes sense: you want the cork to be slightly compressed relative to its natural diameter when it's inside ...
- 48.3k
0
votes
1
answer
144
views
Why does a crushed bottle stay crushed if we keep a cap on it?
If one were to take a crushable plastic bottle and crush it, and, right after crushing, keep the bottle cap , the bottle would retain it's crushed state. However, if the bottle cap were not to be kept,...
- 7,980
0
votes
1
answer
85
views
Why is a firm, inflated stand up paddle board at atmospheric?
I have a new inflatable stand-up paddle board, which is supposed to be inflated to 15 psi. I had to pump a long time and it became very rigid—and when I opened the valve it let out a lot of air. I ...
- 205
0
votes
1
answer
742
views
Does a tire deflate more quickly when not in use and why? [closed]
Answers from a google support the obvious; that tires goes flat when not in use, but when you read the answers carefully they allude more to that - yes a tire can still go flat when not used. My ...
4
votes
1
answer
1k
views
Why does bringing a helium filled latex balloon close to my ear make it feel pressurized?
Title pretty much says it all.
Got my son some balloons for his 1st birthday. He was playing with them while I was holding him and everytime he brought one closed to my ear it made my ear feel ...
- 141
8
votes
1
answer
880
views
Why doesn't a blunt-tip nail crack the wood?
I came across this video, which shows you how to prevent the wood from cracking up at the ends while hammering a nail into it. The proposed solution is to make the nail tip blunt using a plier. This ...
- 12.5k
0
votes
1
answer
552
views
What is causing the doors to move? [duplicate]
New to physics SE (physics too). Today I Observed a strange thing. In my house there are a pair of doors attached to same wall (the wall is about 30 cm wide), both are oppositely hinged (note: we need ...
- 172
60
votes
2
answers
6k
views
Why does pressure in a thermos increase after shaking up hot water and soap?
Whenever I wash my thermos, I put hot water and then some soap in; then I seal the one end with my hand or use the lid. After shaking it up, if I slowly remove the lid or my hand, it expels a little ...
- 581
0
votes
1
answer
143
views
Keep flow rate constant from a drip container
I will be using an elevated container attached to tubing with a ball valve on the end to drip a liquid into my saltwater aquarium to help with coral growth. Conceptually it will be similar to an IV ...
- 1
4
votes
3
answers
571
views
Why can human body sustain relatively high (e.g. up to 30 atm) external pressure?
I found out from the Internet that for average people it's fine to sustain up to 30 atm external pressure, for example when diving. However, given a typical human palm size of 80 cm$^2$, 1 atm means ...
- 195
2
votes
1
answer
104
views
Help me understand the physics of masks
Reference: A. Konda et al., "Aerosol Filtration Efficiency of Common Fabrics Used in Respiratory Cloth Masks", ACS Nano 2020, 14, 5, 6339–6347.
The paper linked above was about ...
