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

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Can you punch a hole in an A4 sheet of paper with your hand?

The Heading says it all. But let me explain it a little further. Suppose you hang a sheet of paper (A4 size), from one end leaving the other end free. Now practically it seems impossible to punch a ...
15
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6answers
3k views

The best way in which a man can pull a train

I have chosen this example as a paradoxical limit, but my question really regards the optimization, distribution and outcome of force when you try to pull a weight: how can you optimize your ...
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2answers
94 views

Add weight in front or behind the moving wheel?

Consider a wheel with bearing and axle bar rolling on level ground. If I want to help the wheel continue moving longer(or faster speed), should I add weight by moving the rider body in front or ...
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2answers
68 views

What makes a material adhesive (or sticky)?

I currently have a bandage on my arm that isn't sticking to me but definitely sticks to itself. It brought up the question: What makes a material sticky? What's happening on the molecular level? Why ...
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2answers
91 views

Does distance traveled by a vehicle after its engine has been switched off depend on its mass at all?

A vehicle moving with some velocity on a rough horizontal road finally comes to rest after its engine has been turned off. Intuitively, it seems a vehicle with greater mass would stop first because it ...
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1answer
67 views

Why is a white cloud formed in the hot water from the pot when salt is added?

Why is a white cloud is formed in the hot water from the pot when salt (NaCl) is added?
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7answers
6k views

Does Earth really have two high-tide bulges on opposite sides?

The bit that makes sense – tidal forces My physics teacher explained that most tidal effect is caused by the moon rotating around the Earth, and some also by the Sun. They said that in the Earth and ...
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2answers
760 views

How hot does the tip of a pencil get while writing?

When writing with a pencil, there seems to be quite a lot of friction - which seems like it would induce heat. How hot would the tip of a #2 pencil get writing on normal copy paper?
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1answer
165 views

How many molecules rub off when I press a key?

I have a lot of questions below but my overarching questions are: Do surfaces rubbing lightly together always strip molecules off of each other? and How can we model that? Clearly the answer to the ...
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4answers
2k views

What happens when we cut objects?

What is the role of the molecular bonds in the process of cutting something? What is the role of the Pauli exclusion principle, responsible for the "hardness" of matter? Moreover, is all the energy ...
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2answers
182 views

Paradox while Cooling & Heating in Air? [duplicate]

I was thinking about how asteroids get "burned" up in the upper atmosphere as they approach the earth surface due to the atmosphere of earth heating the asteroids immensely as a result of air ...
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1answer
38 views

Why is water vapor released when an empty water bottle is squeezed?

I recently came across this tutorial and wondered why vapor will come out when the cap comes off. Heres the Tutorial
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1answer
86 views

Should a pen be light or heavy? [closed]

Expensive pens are usually heavy. Naturally a heavy weight is not expected for an ordinary pen. But in the view of mechanics, the more the inertia the more the capability of holding the speed. Is ...
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2answers
1k views

Why do stickers curl?

When peeling a sticker off its base, the immediate reaction is that it curls; why is this? I am having trouble finding an answer to this. Could it be that the glued side expands upon contact with the ...
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1answer
58 views

How Sound of Mobile Vibration travels through wire of Earphones

This may sound dumb, but I have been observing that, If my mobile phone is placed on the wire of my hands free (earphones) and if my mobile vibrates, I could listen the vibration from the ear plugs. I ...
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2answers
313 views

Why does tea rises in the pot but water don't?

I was wondering when I boil water in a pot it only shakes too much while boiling. But I could not figure out why tea rises in the pot when we boil it. it is also a liquid but it starts rising up till ...
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5answers
175 views

Who does work while walking?

While walking the work done by friction is zero. But who does the work, actually? How someone is getting displaced? This situation also arises when someone climbs without slipping or is climbing a ...
6
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2answers
507 views

Which force is responsible for victory in tug of war?

I'm confused: In a tug of war game on rough ground who will win? The one who applies greater force on the rope or the one who applies greater force on ground?
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3answers
1k views

Why do I always hear remote train horn at night?

This is definitely not an illusion, as many people have the same experience. I have usually lived in places miles away from train stations, which makes it unlikely to hear any train horns during the ...
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7answers
3k 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, ...
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0answers
18 views

Why does cling film (Saran Wrap) cling better to surfaces which are wet or damp than dry?

The product we know in Canada as Saran Wrap is a clear plastic film (no idea of the chemical formulation, believe it to be polyethelene). Among its uses are to cover a dish or bowl. If the hard ...
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1answer
40 views

Does this person get electrified?

Does a person get electrified when his feet are on the floor, his right hand is holding $220~V$ and his left hand holding a piece of wood or any other insulator?
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1answer
73 views

Is it possible that a battery goes flat faster in a cold environment?

I own an old iPod Classic with original lithium-ion polymer battery and I use it primarily while running. Recently I discovered that when a temperature outside is low, usually below 5 C degrees, the ...
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2answers
168 views

Why is it so hard to mix spaghetti with meatballs?

When I cook spaghetti with a sauce that includes meatballs or chopped vegetables, those stay in chunks and won't get uniformly mixed in the pasta. Is there a simple reason for that? Has it been ...
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2answers
36 views

Solar stills with Wine [closed]

Is it possible to obtain more concentrated alcohol by using wine in a solar still instead of seawater? If yes, as I suspected, how does the concentration (of alcohol) of the distillate vary with ...
21
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3answers
807 views

Physics of weird “boing” sound in racquetball courts?

While playing racquetball, I frequently hear a very prominent "boing" sound (or more formally, a chirp). For example, you can hear it in this video when the ball hits the front wall. Does anyone know ...
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2answers
220 views

How do I figure out the momentum of a water balloon when it reaches the person I am throwing it at?

Recently an experiment was performed in which myself and a partner filled a water balloon and threw it back and forth at each other without breaking it. We gradually increased the distance at which it ...
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1answer
77 views

Why there is a time gap between the news presenter and the field reporter?

This one has been in my mind for years, but I simply can not find any reason for this event. The Situation Imagine yourself sitting in the living room while watching television. It's 9 p.m and the ...
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2answers
216 views

Branching lemon drop “smoke rings”

This might be hard to ask, but here goes nothing. I recently poured a cup of water into a black coffee cup. There was a light source--not very bright--above the cup. Anyways, I was squeezing a ...
4
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1answer
218 views

Where is the “event horizon” on a basketball hoop?

I'm watching a lot of basketball this month. A common event is the ball going part way into the hoop and then coming out again. Announcers sometimes claim that the ball was "halfway through" when it ...
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5answers
8k views

Do low frequency sounds really carry longer distances?

It is a common belief that low frequencies travel longer distances. Indeed, the bass is really what you hear when the neighbor plays his HiFi loud (Woom Woom). Try asking people around, a lot of them ...
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5answers
2k views

Where does deleted information go?

I've heard that, in classical and quantum mechanics, the law of conservation of information holds. I always wonder where my deleted files and folders have gone on my computer. It must be somewhere I ...
2
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0answers
61 views

Researching an automobile accident.Wondering if someone can help me as I never studied physics

I am trying do some independent research on a recent auto collision where the information released doesn't seem plausible based on the pictures that I have seen of the accidents aftermath. A ...
3
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1answer
58 views

How come these 3d glasses don't show a difference between horizontal and vertical?

I thought that modern 3d glasses work by having one lens filter horizontally polarized light, and the other filter vertically polarized light. However, I found this pair of 3d glasses at my parents' ...
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0answers
41 views

Is there an efficiency-optimizing layout of items in a refrigerator? [closed]

Is there some optimal layout of items, or types of items (characterized by size, shape, density, solid/liquid, etc) that will allow a common household refrigerator to function with optimal energy ...
4
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1answer
78 views

Why does the majority of smoke leave when flames appear?

When I burn wood, paper, or other plant matter, where there is a flame, there generally isn't too much smoke, but it I blow the fire out, smoke starts billowing up. It billows thicker and thicker as ...
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2answers
84 views

Why slightly closing your eyes let you see the rainbow colors?

So I was sitting and looked at a street lamp outside my house. It is an ordinary lamp that looks something like that: This lamp emits white light and it is about 20 meters from my house. It was ...
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0answers
19 views

How do we get a wave pulse and wave packet/train?

Ok, If a disturbance is localized to a small part of the space for a certain time we get a wave pulse and if the source is active for time greater than to complete a single pulse we get a wave ...
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0answers
62 views

Milk-First School

I have always been struck by the huge amount of different arguments about the issue: When you make a cup of tea, the milk should be poured first or added to the cup after the tea? Wikipedia, ...
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1answer
50 views

Why do we observe opposite motion of trees (nearer) and trees (distant) when seen from a moving frame? [duplicate]

If you are in a moving train or in a bus, what you observe is that the trees which are nearer to you move opposite to the direction of your motion. But the trees which are very far away from you, ...
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2answers
100 views

Observer looking out through the window of a train [duplicate]

When travelling by a train, it seems that the nearby objects move in the opposite direction(which I can explain) but the distant objects appear stationary. I can't explain this. By the concept of ...
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3answers
111 views

Will my car consume more if I plug in my laptop?

I drive a Volvo v40 with a 110hp diesel engine. It usually use 4.6L/100km. If I plug my laptop which is 85W, will this change the fuel need? If so, by how much?
8
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4answers
1k views

Why does a ball bounce lower?

If a ball hits the floor after an acceleration then why does it bounces lower? I mean the Energy is passed to the floor then why does the floor give back less Energy?
8
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2answers
124 views

Why does the sky suddenly look gray through this window?

I am looking to the windowed roof of my building, and I notice that the sky, which has few white clouds, sometimes looks completely gray, as if there was a huge cover of gray clouds, but there are ...
3
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2answers
135 views

Physical Role of Batter in Baseball

Physically, what is the role of a batter in baseball? My question is inspired by How does the speed of an incoming pitch affect the speed of a baseball after it's hit? The answer to that question, ...
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3answers
178 views

How fast can fire spread?

You can build a home-made flamethrower by using a spray and a lighter: (from this YouTube video) But this can be dangerous if the fire gets in the can and the can explodes. So I guess the speed at ...
40
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5answers
13k views

How effective is speeding?

At a simple level, speeding in a car attempts to minimize the time required to travel a distance by utilizing the basic relationship: $$d=st$$ So for a given distance, time should be inversely ...
6
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3answers
218 views

Is it faster underwater to go down without air or up with air?

So I had a very interesting conversation between me and my friends about this topic, but we could not find the answer. The Situation Lets say you are in a pool and you want to touch the bottom and ...
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0answers
38 views

How do whitening toothbrushes work?

Certain "whitening" toothbrushes are sold and I was wondering about the mechanisms behind the tooth whitening process. I suspect this is related to the shape and arrangement of the fibres, probably ...
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4answers
69 views

Why does my house seem to warm faster in summer than it cools in winter?

In summers when we switch off the air conditioner, the room seems to instantly get hot again. But in winter, when we switch off the heater the room seems to remain hot for some time. Why this ...