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

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1answer
136 views

Htting the brakes with a pickup truck full of water

I am looking to settle a bet. My friend and I were discussing truck bed pools, which are pick-up trucks with their beds tarped and filled with water converting them into small temporary swimming ...
3
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0answers
111 views

Why the coil on high tension wires

Today I saw some high tension wires of which some (the middle two) had some large coils wound on top of them as in the image, every 50 meters or so, over a few hundred meters. Does anyone know what ...
2
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2answers
119 views

Why do old tube lights flicker?

When tube lights become considerable old, they start flickering; i.e when the tube lights are switched on, they don't glow immediately, but start flickering. After some time they glow. Sometimes they ...
2
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2answers
339 views

Why is tearing paper irreversible?

Consider a piece of paper. If I pull on it in the right way it tears into two pieces. However, if I push those two pieces together, they do not spontaneously form a single piece. What happens at the ...
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1answer
273 views

Turbulent and smooth flow of water from a tap

When water flows normally from a tap, we can say it is turbulent ( Pic 1 ). But when we attach a piece of cloth to the opening of tap, water flow becomes smooth ( Pic 2 ). We can say that by touching ...
37
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4answers
3k views

What causes this pattern of sunlight reflected off a table leg?

My friend noticed an interference-like pattern around the table leg. However, we do know that interference patterns of sunlight produces rainbow colours. What seems to be happening here?
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1answer
97 views

Why light rays gets scattered when it enters a translucent window pane?

Consider the light source is the light post, outside the window of my house (Pic 1). When the rays from the light post enters through the window pane which is translucent gets scattered and forms a ...
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3answers
207 views

Should these be called “weights” or “masses”? [closed]

Yeah, those circular metal disks. Weights or masses? I call them weights because when I attach them to a spring I'm interested in their weight, but it feels odd saying a "Pick up the 100g weight". ...
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0answers
59 views

Explaining this optical phenomenon

Sometimes when you blow/direct a ring of smoke at a glass window(you can see both your reflections if you stand in front of it as well as the outside) the ring,after some time seems to pass through ...
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2answers
102 views

Is the reason why water in a cup rises if a solid is placed within it the ideal gas law?

Let's say you have a cylinder with water that takes up volume V and has temperature T. When a solid mass is placed within the cylinder, the water momentarily takes up a smaller volume within the ...
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2answers
873 views

Why fast eye movement splits a white LED into the RGB components?

I have a "white" LED as the notification light on my phone. When I look at it straight it looks whitish, but when I move my eyes around (or shake my head) I suddenly see glimpses of red and green (and ...
2
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3answers
259 views

Opening tight bottles

Why do so many people recommend patting/hitting on the lid of bottles, or alternatively on the bottom, in order to open them when they are too tight? Is it even effective? And why would it work?
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1answer
64 views

Do bubbles splash downward?

When a solid ball drops into water, the kinetic energy of the ball pushes water upwards into what we call a splash: Does a similar effect occur when bubbles 'drop' upwards from the water into the ...
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7answers
3k views

How big are clouds? [closed]

How big are clouds? When I look up into the sky I have no frame of reference, so I don't know if they are 200 feet or 2 miles across. When I am in a plane looking out at a cloud, I try to use the wing ...
6
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2answers
529 views

How come a cork float to the side of a glass? [duplicate]

There's a not-so-recent video by a user named quirkology here, where he shows bets that usually work. From @2:19, he puts a wine bottle cap at the center of a glass ...
4
votes
3answers
1k views

Why is boiling not just a surface phenomenon?

The boiling point of a liquid is defined as The temperature at which the vapor pressure of the liquid is equal to the external atmospheric pressure. That being the case, why, in a pot of boiling ...
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2answers
1k views

Which travels further, a football or a soccer ball, when thrown?

I recently answered this question: Laminar Versus Turbulent Flow and it caused me to think of the following situation. Given that an (American) football weighs between Football 400 to 430 grams, and ...
6
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1answer
582 views

Height of Water 'Splashing'

Suppose from a height $H$, I throw a ball of mass $M$ and radius $R$ with initial velocity $u$ into a pool of depth $x$ having a liquid with density $\rho$ and coefficient of viscosity $\eta$. ...
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6answers
12k views

Why can we see through rain?

I am gazing through my office window into a heavy rain. I am thinking that raindrops are like small lenses that bend the light. Thus I am surprised, that I can clearly see other buildings through the ...
2
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1answer
151 views

Would the hot windows break? [closed]

I have a question that I was thinking about for a long time. I live in Kuwait and in the summer season the weather reach 50°C which is extremely hot specially inside a car. What if I was able to ...
33
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3answers
6k views

Push a Boeing 737 on ice: Did this guy have a chance? [closed]

In this video an airport worker (in blue) tries to prevent a Boeing 737 from sliding on ice in heavy winds: Did he even have a chance? On one side of the argument, the airplane is sliding due to ...
3
votes
2answers
185 views

Why speaker beeps when a cellphone is kept near it?

Once I had kept my cellphone near a computer speaker. After some time, a call came over my phone. Strangely, the speaker started humming and beeping till I received it. Why did the speaker started ...
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0answers
92 views

Looking for equation that explains empiric data of tire pressure change due to load

I did some measurements on how tire pressure changes due to different loads in a car. There are still some open questions I can't seem to solve on my own, even though I could already use parts of ...
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0answers
76 views

why do things stick to surfaces when left for a really long time?

I tried to move a cardboard box off the top of a cabinet, which left it on for probably years, and it was insanely difficult to remove. I don't know why this happens, but it also seems that my feet ...
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1answer
163 views

I made a tin can phone using a plastic slinky and paper cups. Why didn't it work?

After watching some videos on Khan academy in regards to the information theory, I spent a few minutes creating a primitive "tin can phone." The materials of my phone are a plastic slinky and two ...
4
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1answer
142 views

Is the Sun dusting my electronics?

I recently noticed this odd dust formation on my gaming console's camera peripheral. The dust is significantly thicker on the right side, with the television in the background. On the left, with a ...
5
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0answers
301 views

Why chewing a battery increases its power? [closed]

I know almost nothing about physics. Last night my TV remote was not working. I chewed the batteries and woh! It still had power left. How does chewing a battery increases its power? I think it's a ...
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3answers
86 views

About energy… created, destroyed?:/

Consider a dam, in that first the hydraulic energy due to gravitational force gets converted into mechanical energy by using turbine. Then those mechanical energy is converted into electrical energy ...
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2answers
131 views

Time delays in live TV talk shows

Quite often I observed that whenever a caller participates in a live TV talk show, there is delay of time to respond a particular question asked by the compère of the program. This delay is due to the ...
2
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1answer
272 views

How does a tightrope walker return to equilibrium?

I do not understand how tightrope walkers return themselves to equilibrium. I am not concerned with the direction along the rope or wire where their base can be large, and they are able to move ...
4
votes
1answer
193 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 ...
2
votes
2answers
95 views

Should the weaker of two air conditions be switched off?

We have two airconditioning systems in the office. For the sake of this question, let us assume the following current conditions: AC1 (old) outputs air of 26°C AC2 (new) outputs air of 18°C Office ...
9
votes
1answer
346 views

Why does hitting a cold bag of water freeze?

About 24 hours ago, I bought a box of 30 pieces water ice. I put them in the freezing compartment and when I came from work I was expecting a nice chilling ice. But when I opened the freezer, I saw ...
5
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0answers
64 views

Cleaning a dirty jar [duplicate]

I would like to wash the inside of an almost empty cylindric jar on whose walls there are remains of a sticky substance such as peanut butter. I do this by filling it up with water and then shaking ...
4
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1answer
133 views

How can I measure the ability of sunglasses to block UV radiation?

The most important function of sunglasses is to protect the eye against UV radiation. When they don't adequately filter ultraviolet (UV) light, it may even be worse to wear them than not to, because ...
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0answers
65 views

How much sunlight would 'fit' through a fibre optic cable?

Say a parabolic mirror were used to focus the full sunlight spectrum into a single strand of optical fibre. Assuming ideal conditions (perfect reflecting surface, focal point smaller than diameter of ...
5
votes
2answers
151 views

Radioactive objects in a student's room [closed]

Contrary to common believe, radioactive materials are everywhere, including inside our bodies, our food, the air we breathe and so on. From Wiki (emphasis mine): The decay of a 14C atom inside ...
8
votes
1answer
2k views

How do candles and wicks work?

The wick of my tea candle was buried in wax. So I lit a piece of paper and stuck it in the wax. Now the wax is burning off the paper, as if that were the wick. The wax itself wouldn't light on ...
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0answers
34 views

Do electrons move easier depending on the way a TIG tungsten head is grinded?

I'm in a TIG welding course, and during the course we (inevitably) messed up a few (suicidal) tungsten heads by grazing/suicide dive into the molten puddle during operation. Standard procedure is to ...
3
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1answer
138 views

Is there any physics arguments behind NASA pen joke

I am just wondering are there any reasonable physics arguments behind difficulty making pen for no gravity conditions. My thoughts are that there are many ways to make it working as: Pressurized ...
6
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2answers
129 views

Why does glue stretch straighter than string?

So I have some bottles of lemonade and I peeled the labels off both of them, revealing the glue underneath. When these bottles were next to each other the glue stuck. I pulled them apart and it forms ...
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3answers
499 views

What is the physics of traffic speed limit? [closed]

In my highschool class the teacher said that the speed limit is designed to prevent drivers from crashing. Does anyone know how they are able to determine the speed limit?
7
votes
1answer
260 views

Is it possible to remove the last block from a the lowest layer of a Jenga tower?

A while back, my brother and I had a discussion about the possibility of removing the last block from the lowest layer of a Jenga tower with the layer immediately above it having only one block in it ...
3
votes
1answer
239 views

Possible to make full loop on a swing only by “pumping legs”?

Is it possible to make a full $360^{\circ}$ loop on the type of swing in a children's playground if I power the swing only by "pumping" my legs? i.e. nobody pushes me?
0
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1answer
88 views

Is it better to walk or run when there is rain? [duplicate]

When I was coming from school to my house, there was heavy rain. Then one of my friends said "Don't simply walk, run fast". Then the question came to my mind: how should I go so as to avoid wetting: ...
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votes
2answers
124 views

The physics of tripping on a stone [closed]

You know, you are walking or running at a certain velocity, your foot gets stuck on an obstacle and you end up flat-faced to the ground. What is the physics behind it? How does the linear motion ...
0
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0answers
61 views

Is there any quantum experiments or effects that you can do at home? [duplicate]

I have heard that you can do the double slit experiment, but is there any other experiments like particle entanglement or observer-induced state collapse?
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2answers
665 views

Will an object with a higher temperature lose its heat faster than a cooler, yet warm object

I'm after the math, which I don't understand yet and can't find elsewhere. The variables are: Two identical cups, A and B The same volume of fluid is contained in each cup, test fluid is water. ...
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2answers
244 views

Does frequently switching a compact fluorescent lamp on and off reduce its lifespan?

What's the physical reason that makes compact fluorescent lamps (CFLs) burn out earlier if we frequently switch them on and off? CFLs typically have a rated service life of 6,000–15,000 hours, ...
3
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1answer
270 views

Why do dead batteries bounce?

It seems like you can test if an Alkaline battery is empty by just dropping it on the floor. If it's empty, it will bounce and fall down. Why is that? Here is a video of it: