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

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Saving energy/ petrol when drving [on hold]

Suppose you are driving on a straight road (with no traffic) at very low speed $v_o$, at one point the road goes downhill (A: grade 3%) and at the bottom (B) makes a V, going uphill again (C), up to ...
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0answers
27 views

AC is more dangerous or DC? [duplicate]

If, though not possible DC also works on specified frequency or follows sine wave form then which one would be more dangerous AC or DC?
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1answer
56 views

Why does paper become uneven when soaked and dried?

Pouring water on a small part of sheet of paper and then drying it makes it uneven, it gets a wave like appearance and seems to have become larger in size. Why?
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2answers
130 views

Why pouring milk from a height makes a chain shape?

I have noticed a chain-like shape when milk is poured from a height into a cup. Actually the chain pattern repeats itself after some distance and again till it reaches the milk in the cup. Any ...
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1answer
28 views

Is, in terms of sound, pouring water in a bottle the analogous of blowing into it?

When we pour some liquid in a closed container, for instance a jar or a bottle, we usually hear two (acoustical) noises: one is the classical turbulent (I guess white) noise, that in my view is ...
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2answers
57 views

What happens when both of Polarizing filter in LCD screen are Horizontal

What would be the result if we replace the vertical polarizing filter in LCD device (screen) with a horizontal filter, what could we see exactly? Would we see the same if we use only one horizontal ...
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2answers
43 views

How can humidity change in a closed room?

I know a closed (not perfectly insulated) space (like a house) can change in temperature if the outside has a different temperature (by diffusion, unless I'm much mistaken). From observation and ...
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1answer
53 views

Why some material is waterproof while breathable?

I am an outdoor lover. Sometimes I am addicted to the jackets made of high-tech materials. There are some materials waterproof while breathable, I wonder how this is possible. They(Liquid water and ...
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3answers
102 views

Why does it seem as if big vehicles “attract” mine when I drive close to them?

When I drive a car at high speed and when I am near to another big car (like a van, or transport vehicle) I feel an attraction to or something push me toward the other big car . What's the physics in ...
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1answer
101 views

What's up with my whipped cream? [closed]

I got a latte with whipped cream this morning, and towards the end of the drink I noticed a peculiar effect. Regardless of how I turned the cup and thereby the coffee, the whipped cream pieces ...
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0answers
26 views

Model of scattering in wet things

You know that clothes and some surfaces become darker when wet (covered in an earlier question: why wet is dark?), because of the disordered reflections or of the refractive index of water or ...
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1answer
64 views

The Egg Smashing Tournament

My cousins and I have a annual egg breaking tournament. First, each of us gets a hard boiled egg. Then, in a bracket tournament style, a pair of us face off in an egg breaking round: one person holds ...
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1answer
68 views

How to obtain this equation for skipping stones over water?

I think I have a decent conceptual understanding of the forces at work when stones are skipped over water. My question pertains to the equation found in this [source][1]. Reproduced in Latex this ...
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3answers
182 views

Why most of physics is somehow related to light? [closed]

It seems that for the past 200 years, every physicist is concerned about light. For example : Newton's particle model, Young experiment, Photo-Electrict effect and Einstein's formula, Special ...
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1answer
84 views

Hula-hoop physics

What are the important parameters to consider when trying to keep a hula-hoop in the air by spinning it around the waist? For instance, when shopping for hula-hoops, one can commonly find its ...
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4answers
4k views

Why are stars white?

That is may be a easy question, but I am not a professional. The sun is a star and when I look at the sun is usually yellow. Why stars in the night are white? I suppose is for the distance. What is ...
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2answers
56 views

What is happening when a jenga block tower wobbles?

Imagine I am 3/4's of the way through a Jenga wooden block game. I have a tower and it is starting to wobble. To me it seems there are two possible causes for this: the wood is compressing and ...
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1answer
145 views

During a turn, do the rear wheels necessarily trace out the same arcs as the front wheels?

When a vehicle makes a turn, the two front wheels trace out two arcs as shown in the figure below. The wheel facing towards the inside of the turn has a steering angle that is greater than that of the ...
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1answer
34 views

How does water-soluble packaging work?

Recently, I have been using detergent tablets in a water-soluble package for my dishwasher. How does the packaging get dissolved in water?
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6answers
2k views

Does placing a lid on a pot affect the rate of boiling?

On the subject of cooking, someone once told me "If you have too much water in your pot after cooking a dish, just turn up the heat and let it boil without a lid for a few minutes". Now I've thought ...
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0answers
31 views

Cloud chamber with normal ice

Is it possible to build a cloud chamber by using normal ice instead of the usual dry ice? The temperature for dry ice is about 200$K$ while it is about 270$K$ for normal ice.
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1answer
37 views

Is it possible to use hot cloudy water as a cloud chamber?

This morning I got some warm water from the shower head to a dark plastic basin to wash some sensitive clothes. During the process lots of tiny bubbles got into the water so it had a cloudy ...
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1answer
53 views

Static electricity experiment

My teacher always asks me to do the experiments on static electricity in winter. I don't know why? What will happen if I conduct the experiment in monsoon?
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10 views

Electricity and it's effects [duplicate]

Why do I hear that bizzz sound sometimes from a electrical pole ? I have studied about heat and light effect of current but is there any sound effects too?
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1answer
159 views

Why do bowlers rub the ball before bowling in a cricket match

Why do bowlers rub the ball before bowling in a cricket match? What is the science behind it? Is it because of friction?
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1answer
84 views

Everyday phenomena for physicists

I am a physicist by training and like to learn more about everyday phenomena, i.e. how things work. All books on this rather general topic go in the direction of introducing physics, they want to ...
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1answer
67 views

Can I manually speed up convection?

Let's say, I have half bucket of boiling water and I have added equal amount of freeze cold water to it. I want to have equilibrium temperature reached as quick as possible. Can I speed up the ...
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1answer
200 views

Why does an aeroplane appear to be moving slowly? [duplicate]

Why does it seem that an aeroplane, even while travelling at 500 kmph at a height of $1.5\text{ km}$ (above sea level), is moving slowly?
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3answers
64 views

Work power and energy

When you push your bicycle up on an inclined the potential energy of the bicycle and yourself increases. Where does this energy come from?
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1answer
98 views

How can a droplet of liquid float on the surface of the same liquid?

This can happen during the rain, or when pouring water. Sometimes small (1-2 mm) droplets of water float on the surface for some time (a few seconds) before coalescing with the big body of water. A ...
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1answer
139 views

How does mud from cycling across a puddle cling onto my back?

While off-roading on a bicycle during a rainy season, it seems inevitable that blotches of mud would stain the back of my shirt at the end of the day. I am not sure the physics behind this. I am ...
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1answer
72 views

Is the moment of inertia of the bicycle wheel relevant for keeping bicycle in the upright position? [duplicate]

When we were taught physics at school and the topic was the Inertia and Flywheel, they used as an example that the moment of inertia of the bicycle wheel is the reason why we are able to keep the ...
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1answer
78 views

Center of mass of a Soda Can [closed]

I have the following problem and can't seem to get my head around it: The mass of the beverage in a full soda can is $m$. The empty can's height is $H$ and mass $M$. A small hole will be drilled ...
55
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2answers
10k views

Why don't fluorescent lights produce shadows?

I have watched light sources such as incandescent lamps and other lamp sources; they have always made shadows. But a fluorescent lamp doesn't make any shadow. What is the reason behind the ...
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2answers
71 views

How to make the mixed water warmer?

Freezing cold. Nastily I still have to do the laundry by hand. And to keep my hands from being frozen I have to add some hot water to the freezing tap water. Let's just suppose that I have the same ...
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4answers
2k views

How does “pushing-start” a dead-battery manual car work? [closed]

A few days ago the battery of my car went (almost) dead. As it is a manual car, my father once told me that the way to get it going without jumper cables was to push it or let it roll down a hill, ...
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2answers
71 views

Why do objects seem to move faster (relatively) when they move tangential to the observer?

I've observed this loads of times while travelling, in cars, trains,etc.I can't quite put it in words and therefore I've roughly made a diagram to assist my question. Assume an observer is travelling ...
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2answers
129 views

Rainbow reflected on TV screen? (pic attached)

According to wikipedia, A rainbow is an optical and meteorological phenomenon that is caused by reflection, refraction and dispersion of light in water droplets... Given that we require ...
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1answer
257 views

Can a liquid boil in a closed container?

The title says it all. When one fills a container (with water for example) and closes it so no air can escape from it, then heats the container continuously, can the liquid boil or completely ...
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1answer
209 views

Why do I hear a deep rumble when I cover my ears?

Probably a trivial thing but a simple google search didn't show anything relevant about it. If I cover both of my ears with my hands, I hear a very deep rumble. If I slowly move my hands away the ...
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2answers
80 views

Why doesn't a glass french press shatter when boiling water is poured in?

When I was little, I accidentally shattered a glass cooking instrument due to applying far too drastic a temperature change to it. Since then, I've been a bit afraid of doing it again. Of late, I've ...
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2answers
132 views

Foam patterns on espresso

When just prepared, an espresso has a thin layer of foam, known as crema, on its surface. As I move my drink from the bar to a table, the motion destroys the homogeneity of the layer, but I've noticed ...
3
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1answer
94 views

Why are charging times so long for Lithium-ion batteries?

Why do rechargeable batteries (e.g., mobile phone batteries) need sometimes several hours to be fully charged? In other words, what are the physical constraints that don't allow me to charge my iPhone ...
2
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0answers
78 views

How do the ice particles interact to produce these magnificent halos?

I googled it and read the Wiki article,but they didn't give any details of its formation. So, I really want to know how these ice halos,that is recently seen near the Arctic, are formed.
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0answers
31 views

Ripples of flowing water on a smooth road surface [duplicate]

Yesterday some friends and I were walking in the rain. We noticed that, on a smooth tarmac road surface, the sheet of water flowing down the road was forming ripples as it went. Why was it doing ...
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0answers
36 views

How can we describe or model the spread of ice during the freezing of the surface of a still lake?

Premise: I live in a place where it is unquestionably wintertime in every aspect of the phrase. I was driving down the street and I drove by a lake. There was a recent and sudden temperature drop ...
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1answer
88 views

How does a faucet work? [closed]

Well I mean how exactly water flows to the sink. How is it pulled through the faucet?
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3answers
8k views

Can kicking a falling phone save it from shattering?

So I saw this tip but I don't think this is true, it would be that your leg or shoe is more flexible than a hard floor so the momentum change would be slower right?
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1answer
115 views

Flakes of Ice in Frozen Milk and Orange Juice

When I was a kid, my family used to put our gallon jugs of milk and orange juice into the freezer when we'd go away on vacation so that they would keep longer. As I remember it, if we were gone for a ...
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1answer
87 views

How can I estimate the cooking time of a roast?

I never remember what worked before, or to write it down someplace. In any case the size and starting temperature will vary. The instructions I learned from refuse to give a time at all, and the ...