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Questions tagged [everyday-life]

Concerns the application of the laws of physics to analyze common situations encountered in everyday life.

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1answer
33 views

Why can I hear the treble sounds through a speaker, such as on my phone, better than I can with headphones?

I'm not sure if this is related to my hearing loss, or if anyone else has noticed it, but I find it easier to hear higher frequency sounds coming out of a speaker that I hold up against my ear versus ...
0
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0answers
9 views

How to calculate the drag force of a cyclist and the drag coefficient?

I have a creative math assignment which my class was tasked to do. Thus I decided to create my work on physics, more specifically aerodynamics. I want to create a function which calculates Drag with ...
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2answers
31 views

How does thermodynamics affect our lives? [on hold]

How does the second law of thermodynamics affect our lives? Could we live without the second law of thermodynamics? What is the whole purpose of thermodynamics affecting our lives? I know this is a ...
0
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0answers
24 views

Derivation of friction in interleaved phonebooks

Trying to understand the simple model in https://arxiv.org/abs/1508.03290, describing the friction between the pages of two interleaved phonebooks. Specifically I don't see how to get Eq. 1. Here's ...
3
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1answer
54 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.
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1answer
18 views

Affect of temperature on carbonation loss

When opening a bottle of soda (any carbonated drink) some of the 'fizz' rushes out. When you replace the cap, CO2 from the soda migrates to fill the empty space in the bottle and eventually an ...
3
votes
1answer
65 views

How fast can we walk? [on hold]

It has been a common observation that as and when we accelerate ourselves, there comes a point after which we cannot stay on the ground completely. I wanted to know whether we can find such a maximum ...
3
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0answers
42 views

While flying over Rome we noticed that during sunset, there was a green color between the red and blue of the sunset sky. What causes it?

The picture has only been trimmed and not edited. The green is visible when the red or orange tapers off into the blue. Is this different from what causes the green flash? We were flying from Rome.
2
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0answers
16 views

Stopping overflow of boiling milk [duplicate]

We all know that milk overflows from the container when boiled. The reason is air trapped under the skin of the milk, can't escape and hence, pushes the skin upwards until it overflows. My mother ...
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0answers
14 views

Adiabatic Expansion of Air blown from mouth [duplicate]

Why is the air blown from our mouth of different temperature as the size of the opening of mouth changes?
1
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1answer
49 views

Will a room heat quicker with a fan blowing on a hot surface? Why?

I got into an argument with someone who thinks that blowing air across a fireplace will make the room heat more slowly, but based upon the principles computer heat sinks use to get heat away the room ...
0
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2answers
77 views

Why are car brakes positioned at the center of vehicle?

In lots of cars, it is possible to see the location of the brake pads through the wheels. Indeed in the majority of cases it seems the brake pads are always located towards the center of the car, i.e....
12
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2answers
479 views

Why does a green stoplight interfere with FM radio reception (more than yellow)? [closed]

While listening to an FM radio station (frequencies between 88 and 108 MHz) in my car, I've noticed that as I pull up to a red light, there's an increase in the amount of noise. It's very noticeable ...
3
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3answers
104 views

Strange behavior of water flow

So recently when I was in a toilet, I noticed a strange behavior of the water that flowed down a nearly vertical pipe of my friend house. Instead of flowing straight down on the nearly vertical pipe, ...
78
votes
4answers
6k views

Why doesn't water actually perfectly wet glass?

According to many high school textbook sources, water perfectly wets glass. That is, the adhesion between water and glass is so strong that it is energetically favorable for a drop of water on glass ...
9
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2answers
596 views

Why do bubbles initially stick to the side or the bottom of a glass while boiling?

When boiling water, I've noticed that bubbles will appear to grow at the bottom of the glass for a period of time and then rise. I've read that bubbles form from nucleation centers but I don't know ...
65
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3answers
6k views

Why does a lot of water vapour come suddenly after the heat source of boiling water is removed? [duplicate]

I have noticed this several times. When I am boiling water, a few seconds before its boiling point, vapours are formed as usual. But if I turn the gas off before boiling, the moment it turns off, I ...
4
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1answer
53 views

When putting water on two pieces of paper they bond. Is that due to van der Waals bonds?

I've been wondering what keeps two pieces of wet paper together when in contact. Does water have any adhesive property? Or does it decompose something from the paper and creates some kind of glue? I ...
7
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0answers
49 views

What's the curve that a piece of card makes when its sides are pushed together? [duplicate]

Suppose that I have a rectangular piece of card or paper and it's lying flat on a table. Then, 2 of the opposite sides of the paper are pushed together slightly, completely smoothly and with the sides ...
2
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4answers
146 views

Why do doors turn?

I really think that I might be overthinking it but I was thinking about a door. When you try and open it with a force, it will produce a translational AND a rotational effect on the door. Any good ...
0
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1answer
53 views
73
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5answers
12k views

Do the weights of two liquids not add when mixed?

I was given an interesting dilemma today. A co-worker saw me adding a liquid (Diisopropyl ethylamine AKA DIPEA) to a flask filled with another liquid (Tetrahydrofuran AKA THF). I needed to weigh out ...
0
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0answers
27 views

What's happening in this demo? Why aluminum ball first jump, then hovers (two AC solenoidal magnetic fields)?

Once in a while google suggest an intriguing video: Professor Eric Laithwaite: The Circle of Magnetism - 1968 There is AC 50Hz driving two concentric, very short solenoids, the outer is longer than ...
1
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2answers
60 views

Why does the diameter of household wire affect the maximum safe current?

The greater the diameter of the wire used in household wiring, the greater the maximum current that can safely be carried by the wire. Why is this? Does the maximum safe current also depend on the ...
2
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5answers
70 views

In thermal spas the temperature of steam is about $50^{\circ}C$, but feels way hotter. Why?

So when you're in hot water and start to move or something the steam feels really hot even though I read its temperature is about 50 degrees Celsius in thermal spas. So why does it feel that warm?
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0answers
26 views

Does ABS increase the breaking distance of a car? [closed]

Question: Can an ABS (Anti-lock Braking System) instead of decreasing the breaking distance actually increase it? If yes, is this its general behaviour, or only in specific circumstances? Wikipedia ...
7
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2answers
1k views

How much energy is wasted by a noisy refrigerator?

I recently bought a new refrigerator for my kitchen. The feet are adjustable but I've been lazy. Whenever the motor runs and the feet aren't all touching the floor there is a loud buzzing noise. As ...
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1answer
49 views

Physics for finning in water

On Scubaboard, people were discussing the reverse frog kick finning technique. Someone mentioned that the propellant force has the square of velocity so it is important to apply a strong velocity ...
3
votes
3answers
92 views

Why do we see virtually inverted image on concave side of spoon?

As we know that a virtual image is always erect then why do we see a virtual inverted image in the concave side of a spoon.
2
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1answer
62 views

Motorcycle wheelie: is it harder at higher speeds, and why?

I am trying to numerically prove that a motorcycle can do a wheelie from its engine power. However, when I use different methods, I get different results... please help connect the dots ! I see two ...
-1
votes
1answer
71 views

My candle is growing living crystals

My candle had no wick left, so I put the jar on a coffee warmer to melt the wax and release the scent. It worked great, the house smelled good. Then I forgot about it. 2 days went by and I just ...
2
votes
2answers
91 views

When you cook food in a microwave oven, why does't the plate get cooked? [closed]

When you cook food in a microwave oven, why doesn't the plate get cooked?
66
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9answers
12k views

Why can't we see images reflected on a piece of paper?

Why can't you see a reflected image on a piece of paper? Say you put a pen in front of the paper, even when light rays are coming from other sources, hitting the pen, reflecting back, and hitting the ...
1
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2answers
41 views

Aerodynamics of cycling into a tail wind

I was looking at Steve Gribble's Cycling Calculator , and I noticed that the aero resistance was higher going 40 mph with a 20 mph tail wind than going 20 mph with no tail wind. Why is this? I always ...
2
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0answers
26 views

Rate of direct (non-thermal) photon-induced evaporation of water?

I have read a long time ago of early experiments in the evaporation rate of surface water, and a discovery that in addition to the Sun's impact on the temperature of the water, it was believed that ...
0
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1answer
38 views

Microwave cooking

This is just a little curiosity I've had, and I wonder what y'all think: I am poaching a chicken egg in a small (about 4 in. diameter) glass dish in my microwave. Let's assume the microwave is set on ...
0
votes
1answer
56 views

Why do we sweat on a hot and humid day but the clothes are able to dry?

I know that on a humid day,water vapour content is high in air and as a result evaporation of sweat is lesser and hence we feel hotter. What I am not able to get is, if water vapour content is high,...
2
votes
1answer
38 views

How does flame takes shape like a normal object?

Playing and doing experiment with flame was one of our favorite childhood interests. But I've always been wondering how a flame takes its shape and behaves like a very light object. If we blow gently ...
2
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0answers
182 views

Why does the humidifier “really” make a stove's flame orange? [duplicate]

I answered this question- Why does the humidifier make a stove's flame orange? and earned 300 rep points for it as an "accepted" answer, but serious doubts have arisen about its correctness. ...
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1answer
50 views

Why is it easier to put one's arm on table for lifting a box?

Why is it easier to put your elbow on the table to lift a box compared to just lifting it, hand in the air? Is it like some kind of torque or fulcrum and lever?
116
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6answers
11k views

Why does the humidifier make a stove's flame orange?

Just like this guy's, the color of my stove's flames were affected by the humidifier as well. Why does this happen? Is it a good thing or a bad thing ?
3
votes
1answer
39 views

What forces the maximum speed of a cyclist on a steep climb?

I know that on a flat road drag is the main force, I have to provide as much force as the drag (and the friction in the drive train) produces. I can also see that the faster I ride, the harder it gets ...
0
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0answers
51 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 ...
39
votes
9answers
11k views

Why do bikes hardly ever skid while braking with the front wheel?

When abruptly braking with the rear wheel on a bike, it tends to skid pretty easily. Doing the same with the front wheel is a very different experience. Instead of skidding, the bike lifts the rear ...
2
votes
1answer
42 views

Relation between shapes and vibrations

I have observed the following shape on surface of water when the bottle was standing on a cooling water machine. I was amazed by the formation because I had not seen this before. I'm not completely ...
3
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2answers
78 views

Why are the “bubbles” at the edges of my soup so large?

At lunch today, I was eating chicken noodle soup. After finishing most of it, I turned my attention to a sandwich and let the soup sit for about five to ten minutes. When I looked back, I noticed that ...
31
votes
5answers
10k views

Why does my bumper scrape when driving fast over a bump but not slow?

When driving my car over a bump or a quick change in gradient (from flat to uphill or downhill to flat), if I don't drive slowly and the bump/change in gradient is large enough, I'll end up with my ...
2
votes
1answer
66 views

Why don't sand get deformed when someone walks on it?

My question is about the structure of sand. Namely, when we walk on the beach sand seems to be very hard to deform, since we push on it from 'above'. But if from another perspective it is also very ...
8
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2answers
225 views

Sharpening Scissors with aluminium foil

There are lots of websites 1, 2,3 that claim you can sharpen scissors by cutting aluminium foil. Does this work? What would be the cause of this?
0
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1answer
36 views

Geometric Condensation Patterns on Windshield

I noticed these patterns in the condensation on the inner surface of my car's windshield when I turned on the defroster. Usually when I see lines like these on condensation I assume it's because of ...