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

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3
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1answer
27 views

Does the force on the bottom piece of a hummingbird feeder depend on the height of the water in the reservoir?

Intuitively I would think that the more nectar you put into the reservoir the more weight it will put on the bottom piece (the tray that holds the open pool of nectar that the birds can feed out of). ...
2
votes
1answer
43 views

How is 'Fog' in summer(sea-elevation) possible?

I am residing in New Delhi (pardon me for any irrelevant data I might include), and I noticed a really interesting thing. It's an average $30^{\circ}\mathrm{C}$ out here, and yet, most/some weather ...
0
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0answers
22 views

Can signal transmission from mobile phones affect battery life of other devices?

Sometimes I hear that you shouldn't keep devices that contain certain batteries close to your mobile phone continuously since signal transmission can affect the lifetime of those batteries. Is this ...
0
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3answers
99 views

How feasible is it to power your home with a bicycle? [on hold]

This article claims "60 Minutes On This Bicycle Can Power Your Home For 24 Hours!" How feasible is this claim? Sounds great - but the skeptic in me says "yeah, right." Hope this is an acceptable ...
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2answers
775 views

How does the magnetic field get induced in car's tire?

I was amazed to see how my car's tire started attracting the nuts and bolts, how in the world did it induce the magnetic field? Never heard of such phenomena!!!
3
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0answers
36 views

Why do insulated cooler bags have aluminum on the inside?

I understand that aluminum can partially reflect the sun and other heat radiation if placed on the outside of cooler bags. However, most types of cooler bags only actually have the foil on the inside ...
5
votes
1answer
246 views

energy efficiency - dryer vs hang+dehumidifer

When I have wet clothes coming out of the washing machine, I can either tumble-dry them in an electric clothes-dryer, or I can hang them to dry. But I can only hang them in a basement. The basement ...
3
votes
1answer
93 views

How does eating a cold ice cream actually heat up your body? [closed]

The question is the title itself. During winter one of my friend told we'll have an ice cream. And rest of us where like are you nuts. He was like cold ice-cream actually heats up your body. Even I ...
14
votes
6answers
13k 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 ...
1
vote
1answer
35 views

What is the average range of voltage of lightning in sky?

I wondered how much energy is required to produce , such a loud sound? What is the average range of voltage in sky? Is there any possible way to store it ,and use when needed?
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0answers
22 views

How humidity circulates

I was wondering something about humidity circulation. I have observed that, if I left the door of my air conditioned lab slightly open during rainy season the humidity levels increases in the lab ...
5
votes
1answer
964 views

Why does the light at the bottom of the pool form this awesome pattern?

Take a look at the following picture: Why does the light at the bottom of the water form this pattern? I have also seen the same phenomenon in all the swimming pools I've ever visited, of whatever ...
12
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3answers
10k views

Does sound propagate further in freezing weather?

A few days ago I went for a walk in the evening. We're having winter with a little snow and freezing temperatures. We're in a quiet, shallow valley with a train station about 1km from us. I heard a ...
37
votes
8answers
30k views

Why CAN we see the new moon at night?

I understand that the Moon's phases are determined by its position in orbit relative to the Sun. (See: Full Story on the Moon). The "shadow" is not cast by the Earth (a common misconception - this is ...
4
votes
3answers
2k views

How can we see the moon while it's between the Earth and the Sun? [duplicate]

I know this sounds like (and probably is) a stupid question, but I can't figure it out. As far as I know, the crescent shape of the moon is when the moon is on the sunny side of the Earth, but that ...
17
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6answers
5k views

Why can we see the moon when it is between the Earth and the Sun? [duplicate]

A rather stupid question, why can we see the moon when it is between the Earth and the Sun?
35
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3answers
3k views

Why is ice made from boiled water clear?

A common trick to make clear water ice is to boil pure water prior to freezing it. Why does that work and what are the white inclusions in ice that was made from unboiled tap water?
56
votes
5answers
11k views

Why is water clear?

Water appears transparent to visible light, yet most other objects are opaque. Why is that? Is there an explanation why water appears transparent? Is water transparent at all wavelengths, or are ...
2
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1answer
193 views

Rotation motion like the number 8

I'm a college student majoring in culinology and I'm trying to find out the reason or method of the number 8 motion. Responses doesn't have to be in culinology examples, but that would be a great help ...
4
votes
3answers
178 views

Why do we hear better during the night? [duplicate]

At night, we hear weak and far sounds approximately clear, while during the day we cannot. My high school physics teacher was saying that “this is because of interference of sound waves. During the ...
2
votes
6answers
823 views

Why does driving faster make my windshield catch more rain?

I've noticed that, when I'm driving and it's raining, the faster I go the more rain I get on the windshield and the faster I have to run the wipers to compensate. When I'm stopped at a red light I ...
3
votes
2answers
445 views

Why do racing tires (slicks) provide more traction with the road?

Google: By eliminating any grooves cut into the tread, such tires provide the largest possible contact patch to the road, and maximize traction for any given tire dimension. My understanding is that ...
59
votes
2answers
3k views

Why does wet hair keep its shape when it dries?

When I wash my hair and go to sleep, my hair is impossible to comb in the morning, stubbornly sticking to the shape it assumed during the night. The only way to get it right is to wet it again and ...
11
votes
14answers
541 views

How to pour water from a bottle as fast as possible

When one pours water out of a bottle, it first flows smoothly but then a pressure 'blockage' develops and the pouring becomes interrupted and turbulent, so that the water comes out in splashes. This ...
1
vote
1answer
55 views

How is the energy efficiency in bicycles accounted for? [duplicate]

Bikes are more efficient than walking, but that's only because roads are flat so wheels make sense, right? Does it make sense to say that this fact is simply gained by putting a lot of energy into ...
1
vote
1answer
42 views

Why does length of objects seem different in different configurations of object and observer?

Today, I had gone to my friend’s garden. There was a dried water well in his garden. We got curious that know how much its depth is. First, we stood on top of the well and estimated its depth. We ...
2
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1answer
1k views

Teflon and induction cookware

I remember once getting new Teflon (non-stick) cookware; however, when I tried this new cookware on my induction cooker the cookware did not heat up. My regular steel cookware worked just fine on the ...
9
votes
3answers
152 views

'Slapping' sound when trains pass each other

I have noticed that when riding in a train travelling at over 100 kmh$^{-1}$, a loud 'slap' can be heard when another train travelling at a similar speed passes in the opposite direction, followed by '...
-1
votes
2answers
120 views

Physics behind seemingly-impossible “rice bowl suction” Guinness world record? [duplicate]

By pressing a rice bowl on his abdominal muscles, Zhang Xingquan was able to create enough suction to pull a 36.15 tonnes heavy train for 40 meters Source: Guinness world records website. How does ...
3
votes
0answers
45 views

How does the bowling computer know I'm right handed? [closed]

I went bowling the other day and after I rolled my first ball I was suprised it was written on the screen that I was "right-handed". How was that figured out? My first guess is that there is ...
30
votes
6answers
15k views

Why does wet skin sunburn faster?

There is a popular belief that wet skin burns or tans faster. However, I've never heard a believable explanation of why this happens. The best explanation I've heard is that the water droplets on the ...
4
votes
2answers
112 views

Why is it easier to get sunburnt in the water? [duplicate]

I went today to the swimming pool and I remembered that when I was younger my mom used to tell me to be careful because you get sunburnt much more easily in the water than in the ground. I never gave ...
8
votes
1answer
141 views

What is the physics behind “mocha diffusion”?

A friend shared a video on Facebook of a process for glazing pottery called "mocha diffusion." A light-coloured glaze is applied to a pot and then, while it's wet, a black liquid is dripped into it. ...
8
votes
2answers
147 views

Why do headphones tangle themselves whereas shoe laces untie themselves?

Why do headphones tangle themselves whereas shoe laces untangle or untie themselves? Why aren't we using the phenomenon to create headphones that tangle less and shoe laces that untie less?
7
votes
4answers
4k views

How does a canvas water bag cool water?

I was reading about this water bottle by Botl that behaves like a canvas water bags to keep water cool. I found out that this idea is an old idea and cars would drive with water bags in front as shown ...
83
votes
11answers
13k views

Why is filling a balloon from your mouth much harder initially?

Why is it that when you first fill up a balloon, it's hard to get air through, but after inflating it a bit, it becomes much easier to further inflate the balloon?
1
vote
1answer
64 views

By how much does the temperature of a cool Cola can increase by condensation of the ambient moisture on its surface?

Assuming standard ambient temperature and pressure, how can we estimate the increase in the temperature of a typical, cool beverage can produced by the condensation of ambient moisture on its surface? ...
1
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1answer
170 views

Is putting a charged balloon up to a neutral wall polarization AND temporary induction, or just polarization?

Is putting a balloon that is charged up against a wall and having it stick polarization AND charging by temporary induction, or just polarization?
23
votes
6answers
89k views

Why is AC more “dangerous” than DC?

After going through several forums, I became more confused whether it is DC or AC that is more dangerous. In my text book, it is written that the peak value of AC is greater than that of DC, which is ...
3
votes
3answers
4k views

How much energy was consumed when we turn on/off light?

My parents told me to turn off the light when I am not using it. But I remember my physics teacher told me that the action of turning on/off a light can cause huge energy. I am wondering how much is ...
3
votes
2answers
1k views

Would a small puddle of water evaporate faster if you spread a dry towel over it?

Let's say you spill 10ml of water on the kitchen counter. It forms a small puddle that would evaporate after a while (assuming room temperature and sane humidity). Would spreading a large, dry towel ...
4
votes
3answers
8k views

Pressure inside a light bulb

It is known that nowadays most light bulbs are filled with gas in order to minimise the evaporation rate of tungsten. Is e.g. argon put into the bulb with reduced pressure, so that the glass doesn't ...
0
votes
2answers
178 views

Tennis ball in a glass of water

If you pour water into a glass half full and put a tennis ball there it would aim to its sides. But if you pour water completely full a ball would aim to center. It's definitely related to a surface ...
81
votes
6answers
10k views

Why is oil a better lubricant than water?

How come mineral oil is a better lubricant than water, even though water has a lower viscosity? When two surfaces slide over each other with a gap filled with a fluid, the different layers of the ...
4
votes
1answer
145 views

Entropy change in a boiling egg

Yesterday in a rather intuitive Q/A session, by a visiting researcher in my town, this question got my attention.What he said was that if you boil an egg, the entropy inside the egg would increase.Now ...
4
votes
3answers
123 views

Would life (as we know it) be possible without the weak interaction?

I understand why the strong interaction is important in everyday life (it holds nuclei together and also allows the fusion reactions that power the Sun) and also why the electromagnetic interaction is ...
1
vote
1answer
43 views

What's the minimum time scale for a candle to be lit in order for it to establish a steady state?

My Understanding When a candle is lit initially, it goes through a few stages (see, e.g. this explanation from the National Candle Association): Wick burns. Crusted wax on wick melts, evaporates ...
1
vote
2answers
293 views

Electricity Flow and Ground Wire

Pre-face: My step-father and I were turning the heat down on the water heater. He demonstrated that touching the ground wire doesn't shock you. My understanding is that the ground wire doesn't have ...
3
votes
2answers
47 views

How can you easily measure your visual range? [closed]

There are numerous ways of estimating your hearing range by generating sine waves at a certain amplitude and trying to tell when you are no able to hear a difference between on and off anymore. An ...
1
vote
1answer
92 views

How does GPS on an airplane report a 100 km error?

On a flight across Europe, I took my iPhone out to see if the GPS can find my position. I was sitting away from a window, so reception would have been bad. I wouldn't have been surprised to get no ...