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Questions tagged [everyday-life]

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

3
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1answer
67 views

Where do the air bubbles inside the pool come from?

Here's a pic of my legs in the pool water. There are tiny air bubbles on them. I thought this is the result of air coming out of my leg, but I learnt that this is not the case. Also, there seem to be ...
0
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1answer
39 views

When we burn a wood it burns with flame although it do not contain any gaseous substance [duplicate]

In books it is given that flame is only produced when gaseous substance burn but when dry wood is burnt it also burn with flame.why.
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2answers
53 views

Why do popcorns sizzle after popping?

Why do popcorns make a sizzling sound after popping? At first I thought it might be due to moisture, but according to this, that is not the case, as the water present in the corn has already ...
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1answer
46 views

Phase change in oceans

When ice cube melts in water the level of water doesn't change but when glaciers melts in oceans sea water level increases why?
18
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4answers
2k views

Why does a car's steering wheel get lighter with increasing speed [closed]

I've noticed it is difficult to turn the wheels of a car when the car is stationary, especially cars without power steering, which is why the power steering was invented. However, I've noticed it ...
0
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1answer
48 views

Why does the flame of a gas stove not spread backwards?

On lighting a gas stove the flame is active only above the burner. However, the gas input from beneath the burner and all the way to the pipeline contains gas fuel. Why doesn't it all ignite up ? I am ...
3
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2answers
116 views

Why does a person carry more weight when sitting down?

Today, while shopping for a chair at a shopping mall, I saw this poster regarding the amount of weight a person is carrying when doing various activities. When standing upright, one carries 100% of ...
4
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2answers
120 views

What opposes a smooth motion of a rubber eraser on a glass surface?

A metal block smoothly moves on a glass surface. But a rubber eraser doesn't move very smoothly on a glass surface. In each of the cases, the surfaces are smooth at the macroscopic scale. If the ...
9
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2answers
2k views

Why does a metal block make a shrill sound but not a wooden block upon hammering?

When hammered, a metal block makes a shrill sound but not a wooden block of identical shape. Is it that the wooden block vibrates with lesser frequency than the metal block? If so, why is that? Also ...
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2answers
79 views

What causes my “kitchen witch” to move? [closed]

Not a physics person but curious about something going on and hoping someone can explain. I have a kitchen witch hanging from my kitchen ceiling on some fishing line and it’s constantly swaying and ...
1
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1answer
44 views

Why are there these other “harmonics” (violin-specific terminology) in violins?

I've often read explanations of how standing waves form on the string of a violin and their harmonics but there is another phenomenon I've never seen explained: When you play certain notes, musicians ...
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0answers
30 views

Are sounds louder at night, in the winter? [duplicate]

Surface temperatures of -40C and +40C are not unheard of in habitable areas on Earth. That's a variation of over 30% in density (for a given barometric pressure). Does that mean that for the same ...
66
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4answers
11k views

Why don't you get burned by the wood benches in a sauna?

When you go to the sauna you may sit in a room with 90°C+. If it is a "commercial" sauna it will be on for the whole day. How does it come that when you sit on the wood you don't get burned? I ...
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1answer
39 views

How can I avoid electrostatic discharge?

I recently started an internship in an office with a rugged floor everywhere. After a few days, I started receiving electrostatic discharge all the time after I walked a little bit around the floor (...
3
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3answers
76 views

Why is blowing so different than sucking? [duplicate]

Why is it so easy to blow out a candle from a significant distance, but nearly impossible to suck enough air to do the same? Even without focusing the airflow through a nozzle or something, this ...
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4answers
110 views

Can we cool a room by opening the door of a refrigerator? [duplicate]

The room cools for a moment but then it becomes warmer.. Why?
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2answers
147 views

Should I walk or run to my towel when naked and wet? [closed]

This morning when I got out of the shower, I realised I had left my towel in the bedroom. Naked and wet I ran as fast as I could to get the towel. On my way back I didn't run, but rather walked, and ...
0
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1answer
41 views

“Plushness” of a simple mechanical damper?

What heuristics generally define the "plushness" of a mechanical damping or braking system? For example, if a person or some mass is to collide with a fixed wall or the ground (e.g., after a vertical ...
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4answers
61 views

Bicycle Fuel equivalent on l/100km

Is there a way I can calculate the equivalent how much a Human powered bicycle consumes in the equivalent l/100 Km of Diesel fuel? And also can I calculate the same for Gasoline fuel? And for ...
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1answer
98 views

Why school buses are not painted in red? [closed]

I came to know recently about why the road signals such as dead end signal or something like these have red paint because this colour's dispersion is very least among other rainbow colours. But my ...
1
vote
1answer
42 views

Why do headlights through a window move around a room?

As I lay in bed this evening a few cars have passed by and my blinds are down. As they come down the street, you can see a sliver of light on the wall on the side of the room that is in the direction ...
0
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1answer
50 views

Why do color of things fade and where it goes? [duplicate]

Suddenly this question comes to mind when i saw a sticky-label faded, when compared to comparatively new one. So question here is does it simply fades away like physical particles or is there anything ...
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0answers
26 views

How does changing the moment of inertia of an object being swung by a human affect the kinetic energy?

If a human swings a baseball bat with moment of inertia $I$ at velocity $\omega$, as hard as he/she can the swing has a given kinetic energy. If you increase $I$, then the human will not be able to ...
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3answers
71 views

How are these utensils microwave-safe? [closed]

These types of utensils are starting to become popular nowadays. I checked their product description which says that its outer surface ( i.e. the red part) is microwave-safe plastic while the inner ...
17
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6answers
404 views

Can you jump higher if you run? If so, why? (High jumping)

I have often wondered why high jumpers can jump higher if you run. The way I see it is that you only build up horizontal speed, and since you're running on a plane, I cannot see how this speed can be ...
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1answer
24 views

Pouring liquid out of a bottle smoothly

Can one calculate the vacuum pressure created inside a bottle when pouring liquid from it? Glass bottle 38mm diameter orifice
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2answers
97 views

Which one is better to boil water, using high heat or less heat?

Consider that I have a water boiling kettle as below. Assume that it is made of metal, not plastic (but plastic probably also will do). Assuming I can adjust the power it uses to boil the water with ...
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3answers
102 views

If I leave a glass of water out, why do only the surface molecules vaporize?

If I leave a glass of water out on the counter, some of the water turns into vapor. I've read that this is because the water molecules crash into each other like billiard balls and eventually some of ...
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1answer
40 views

Can you polarise a lens by rubbing it with your finger?

Here's a phenomenon that you all might have come across . I took two photos on my phone, keeping it in landscape mode. I noticed that the light rays get polarised, or rather "smudged" when I rubbed ...
2
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3answers
73 views

Basic question about electric shock

When we are negatively charged, and we touch a doorknob for example, why does the shock happen (i.e. the flow of charge)? I understand that the electrons want to flow to positive charges, and I know ...
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0answers
30 views

If we're wearing a metal watch, do we get an electric shock on our wrist when we're charged and touch a conductor?

As the charge would flow to/from the watch, assuming I'm insulated from the ground with rubber soles, or standing on glass.
11
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3answers
1k views

Are rainbows three dimensional? If so, what determines their depth? [duplicate]

I am wondering whether rainbows are three dimensional, and if so, what determine their depth? How to calculate the depth of a rainbow, given its radius? From what I understand, all rainbows are ...
-5
votes
1answer
62 views

When we burn a match stick it did not go at $c$ speed, why?

When we burn a match stick then mass is converting into energy then according to the relativity match stick particles should go at speed of light but it did not happen why
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1answer
35 views

Why can I hear the treble sounds through a speaker, such as on my phone, better than I can with headphones?

I'm not sure if this is related to my hearing loss, or if anyone else has noticed it, but I find it easier to hear higher frequency sounds coming out of a speaker that I hold up against my ear versus ...
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0answers
15 views

How to calculate the drag force of a cyclist and the drag coefficient?

I have a creative math assignment which my class was tasked to do. Thus I decided to create my work on physics, more specifically aerodynamics. I want to create a function which calculates Drag with ...
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2answers
46 views

How does thermodynamics affect our lives? [closed]

How does the second law of thermodynamics affect our lives? Could we live without the second law of thermodynamics? What is the whole purpose of thermodynamics affecting our lives? I know this is a ...
0
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0answers
33 views

Derivation of friction in interleaved phonebooks

Trying to understand the simple model in https://arxiv.org/abs/1508.03290, describing the friction between the pages of two interleaved phonebooks. Specifically I don't see how to get Eq. 1. Here's ...
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1answer
65 views

How does sharpening a pencil make it darker?

Why does a sharp pencil write better than a blunt one? Note that the force applied on each case is identical.
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1answer
20 views

Affect of temperature on carbonation loss

When opening a bottle of soda (any carbonated drink) some of the 'fizz' rushes out. When you replace the cap, CO2 from the soda migrates to fill the empty space in the bottle and eventually an ...
3
votes
1answer
72 views

How fast can we walk? [closed]

It has been a common observation that as and when we accelerate ourselves, there comes a point after which we cannot stay on the ground completely. I wanted to know whether we can find such a maximum ...
3
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1answer
69 views

While flying over Rome we noticed that during sunset, there was a green color between the red and blue of the sunset sky. What causes it?

The picture has only been trimmed and not edited. The green is visible when the red or orange tapers off into the blue. Is this different from what causes the green flash? We were flying from Rome.
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0answers
16 views

Stopping overflow of boiling milk [duplicate]

We all know that milk overflows from the container when boiled. The reason is air trapped under the skin of the milk, can't escape and hence, pushes the skin upwards until it overflows. My mother ...
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0answers
15 views

Adiabatic Expansion of Air blown from mouth [duplicate]

Why is the air blown from our mouth of different temperature as the size of the opening of mouth changes?
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1answer
60 views

Will a room heat quicker with a fan blowing on a hot surface? Why?

I got into an argument with someone who thinks that blowing air across a fireplace will make the room heat more slowly, but based upon the principles computer heat sinks use to get heat away the room ...
0
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2answers
82 views

Why are car brakes positioned at the center of vehicle?

In lots of cars, it is possible to see the location of the brake pads through the wheels. Indeed in the majority of cases it seems the brake pads are always located towards the center of the car, i.e....
12
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2answers
486 views

Why does a green stoplight interfere with FM radio reception (more than yellow)? [closed]

While listening to an FM radio station (frequencies between 88 and 108 MHz) in my car, I've noticed that as I pull up to a red light, there's an increase in the amount of noise. It's very noticeable ...
3
votes
3answers
116 views

Strange behavior of water flow

So recently when I was in a toilet, I noticed a strange behavior of the water that flowed down a nearly vertical pipe of my friend house. Instead of flowing straight down on the nearly vertical pipe, ...
81
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4answers
6k views

Why doesn't water actually perfectly wet glass?

According to many high school textbook sources, water perfectly wets glass. That is, the adhesion between water and glass is so strong that it is energetically favorable for a drop of water on glass ...
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2answers
684 views

Why do bubbles initially stick to the side or the bottom of a glass while boiling?

When boiling water, I've noticed that bubbles will appear to grow at the bottom of the glass for a period of time and then rise. I've read that bubbles form from nucleation centers but I don't know ...
66
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3answers
6k views

Why does a lot of water vapour come suddenly after the heat source of boiling water is removed? [duplicate]

I have noticed this several times. When I am boiling water, a few seconds before its boiling point, vapours are formed as usual. But if I turn the gas off before boiling, the moment it turns off, I ...