All Questions
Tagged with everyday-life pressure
101
questions
179
votes
2
answers
19k
views
When separating an Oreo cookie, why does the cream stick to just one side only?
There is probably some reason for this, but I can't figure out what it is. I agree that it probably doesn't happen 100% of the time, but most all of the time, the cream is clinging to just one of the ...
- 2,637
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
75
votes
5
answers
66k
views
Why does a candle blow out when we blow on it? Our breath is 16% oxygen and only 4% CO2
Don't say that a layer of carbon dioxide covers the flame, because our breath has more oxygen than carbon dioxide.
Also, our breath does not extinguish the flame by cooling it as it is itself warmer ...
- 2,326
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
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 ...
- 48.4k
42
votes
12
answers
122k
views
Does car tire pressure change with weight of car load?
Does tire pressure measured by a meter on tire gauge change with load? (I am not interested in pressure produced by car tires onto the road).
Car spec usually says "inflate to 220kPa normal load, ...
- 522
39
votes
4
answers
17k
views
Should a soda bottle be stored horizontally or vertically?
I am having an argument with my friend about how a nearly-full soda bottle should be stored in the fridge, with the goal of keeping the soda from going flat (i.e. keeping as much of the gas dissolved ...
- 520
31
votes
5
answers
80k
views
Why does my refrigerator door resist opening?
After closing my refrigerator's door I noticed that it's much harder to reopen it immediately, as if there's an underpressure. Only after a minute or so it opens normally. How can this be explained?
- 421
28
votes
6
answers
56k
views
Why does my door shut faster when the window is open?
I've noticed that if I shut my door when the window is open in a room, the door will tend to shut faster. If I shut the door when the window is closed with a normal force it will not fully close as if ...
- 431
25
votes
6
answers
6k
views
Why does low tire pressure reduce fuel efficiency?
I've always thought that it was because the frictional force on the tire was increased due to the bulging of the tires increasing the surface area in contact with the road. However, a colleague of ...
- 391
23
votes
4
answers
6k
views
Why do bubbles make a sound?
I have an understanding of how bubbles work. They encapsulate air (or other fluids) in a membrane caused by surface tension.
When they pop, there is often a sound. Sound is a type of energy, kinetic ...
- 459
14
votes
5
answers
26k
views
Why will crushing a partially empty 2-liter bottle keep the soda more fizzy?
One of the curses of 2-liter bottles is that when carbonated beverages are stored in them for long periods (i.e. days between drinks) at least the last liter ends up being flat. However, if after ...
- 381
11
votes
2
answers
833
views
What if the lid of a pressure cooker was suddenly released?
My dad and I have tried to calculate the strength of the explosion if the lid was suddenly freed. We took some measures:
Lid mass: $0.7 \textrm{kg}$
Lid surface: $0.415 \textrm{m}^2$
Internal ...
- 211
11
votes
1
answer
816
views
What pressure or tension occurs in a glass jar when I pour boiling water inside?
Sometimes it happens that when you pour a boiling water into a glass jar, it cracks. Since glass is very hard material and resilient to pressure, the tension must be very high. Is it possible to ...
- 3,109
10
votes
2
answers
2k
views
Movie airplanes and suction
Having watched a recent action movie (with zombies in it) I wondered whether the suction from a hole in the airplane's hull would really be able to rip out luggage, persons and even seating benches.
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- 9,169