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

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1answer
102 views
+50

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 $\eta$. ...
32
votes
6answers
7k 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
votes
1answer
127 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 ...
32
votes
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
74 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 ...
1
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0answers
71 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 ...
0
votes
0answers
51 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 ...
0
votes
1answer
54 views

Cinema and TV pictures [closed]

Can you explain (a link will do) how pictures move on a TV screen? In a cinema projector a shutter interrupts the flow of light 48 times a second, does a similar trick work on a TV screen, does it ...
1
vote
1answer
67 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 ...
3
votes
1answer
61 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 ...
3
votes
0answers
41 views

Why does temperature affect the toxicity of aluminium? [closed]

They say that it is OK to cook (tomato sauce) in aluminium pans, but that it is not advisable to store food in them at room temperature or in the fridge/ freezer. Can someone explain the physics ...
5
votes
0answers
167 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 ...
0
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3answers
65 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 ...
1
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2answers
75 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
votes
1answer
85 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 ...
5
votes
1answer
64 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
88 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 ...
7
votes
1answer
181 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
votes
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
votes
1answer
64 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 ...
0
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0answers
61 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
133 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 ...
6
votes
1answer
760 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 ...
0
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0answers
27 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 ...
2
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0answers
84 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
votes
2answers
102 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
161 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
139 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
117 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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0answers
31 views

How much harder an aluminum bat will hit a ball as compared to a wooden bat?

I was thinking like what's the major difference between using aluminum bat and wooden bat means how much harder will an aluminum bat will hit a ball as compared to wooden bat ?
0
votes
1answer
65 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: ...
-3
votes
2answers
72 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
58 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?
0
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1answer
59 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. ...
1
vote
2answers
60 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
votes
1answer
214 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:
1
vote
4answers
220 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 ...
21
votes
1answer
1k views

Why does a match go out if you hold it so the flame is up?

I have noticed something which may have been noticed already: take a match, and light it, then hold it so that the flame is directly above your hand. The flame will eventually go out. My guess as to ...
8
votes
4answers
996 views

Two people are holding either end of a couch, is one person exerting more force than the other?

I was carrying a couch with my flatmate yesterday, and I started thinking about this. Often when carrying objects like this, one person will be taller and has thus lifted his end of the couch higher ...
0
votes
5answers
280 views

Explain why quantum behavior is not observed in daily life

People always ask: How come we don't see any "Wave" attached to a classical object such as a car? You always see the object in the same place without any uncertainty. I am sure there are answers, ...
5
votes
3answers
1k views

How much is if my internet provider says “we have increased your WiFi connection by 2 decibels”?

I understand the definition of decibel as a logarithmic unit for intensity of anything. I just cannot imagine its "actual size" when comes to the wireless connection. Can you provide something ...
0
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0answers
83 views

Why Does Moving a Cup of Coffee Up and Down whilst carrying it Make it less Likely to Spill?

Sometimes I have a Very Full Mug of Coffee and I am trying to carry it without it spilling. I noticed that if I moved the Mug up and down when carrying it, it seemed to settle the coffee and make it ...
5
votes
1answer
938 views

Why is the shadow of a wind turbine a bit slow at first then very quickly, etc. and not equivalent to the wings?

When I stand at a wind turbine and look at the shadow on the ground, the shadow is a bit slow at first then very quickly, etc. Very strange.
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0answers
77 views

Can a microwave oven induce an accumulation of static charge in food?

I often "touch test" microwaved food to see if it is heated up enough to my preference. In doing so, I sometimes notice the characteristic tingle of a static discharge between the food and my finger ...
1
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1answer
68 views

How do we “cancel out” the torque from running?

Running certainly causes a torque on our body, as we are propelled forward via our feet; why doesn't this torque cause our bodies to spin about their center of mass?
0
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0answers
67 views

Why do I hear a squeak in my pipes when my neighbour runs his water?

I just installed a new water-heater in my apartment. Now, I hear a distinct squeak from some rooms some times when I or some neighbour run the water. Could not hear this before, and the pipes are all ...
5
votes
1answer
69 views

Long, blurry reflections in wet road [duplicate]

When driving on a wet highway at night, any surface emitting or reflecting light will have a reflection right under it that is blurry and seems to stretch to infinity. This is not exactly what I am ...
1
vote
0answers
28 views

Twisted earphones-wires [duplicate]

Just the other day I kept aside my earphones after listening to music for a long time, only to find it get twisted, well and good! This happens every time. I feel it is a really strange phenomenon - ...
1
vote
1answer
115 views

Real life physics problem: Why is my desktop computer affected by my plasma ball?

Note: this is strictly a physics question, not meant to be an advertisement I was running my desktop with a plasma ball on the side. The desktop has a touch screen enabled. I started to notice that ...
1
vote
1answer
106 views

Why does a diver changes his body positions before and after diving?

Before a diver dives in a pool, he changes his body positions several times. When he is about to jump from board he extends his arms and legs but sometime after jumping he closes his body in a ...