Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

Questions tagged [everyday-life]

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

0
votes
1answer
61 views

How has the Earth's air pressure varied over geological time scales?

It is estimated that the Earth is losing about $5 \times 10^7 kg$ per year. Most of it due to hydrogen loss. I suppose this has an impact on the pressure of the atmosphere in general. Thus, I am ...
0
votes
0answers
17 views

Aerodynamics of a bed sheet

Given the mass of a bed sheet and its area, is there any way of determining the probability of it landing "perfectly" when it is jerked up on the bed (by jerk i mean when you are making your bed and ...
0
votes
0answers
25 views

What is the lift coefficient of human body?

Assuming we can change angle of attack by changing our hands orientation what is the maximum aerodynamic lift coefficient of human body?
1
vote
2answers
67 views

Increase in temperature after an unexpected rain during summer

Why we feel an increase in temperature of atmosphere than usual after an unexpected rain during summer? Usually the raining should have to reduce the temperature of atmosphere.
0
votes
1answer
22 views

Fastest way heat water (or some other liquid or material)

If I want to heat lets say, 1 liter of water - would it be faster if I heat half a liter, and then another half a liter? or slower? my guess is that its not equal (lets assume that the time it takes ...
0
votes
2answers
69 views

Why are fridge doors magnetic?

Why do fridge magnets stick to fridges? What purpose does a magnet have in a fridge? Why do the magnets stick so well to the fridge doors but not so well to keys or nails?
6
votes
2answers
52 views

Gravity “sorting” and French Press coffee

I have read about the Earth's sorting of different-sized grains of sand and such. Larger particles are supposed to fall through water faster. I've seen it demonstrated before and have full faith. But ...
4
votes
1answer
106 views

I was wondering if the mass of an object can be measured by the effect it has on a body of water if it was dropped from a certain height? [duplicate]

The question: Height of Water 'Splashing' asks about the height of the splash when an object is dropped into water, but there are other parameters that can depend on the mass and velocity of ...
-1
votes
3answers
78 views

Life physics: falling objects

I've started wondering for a while WHY we experience so much damage when we hit a ground after a free fall? What forces are responsible for that? After some thinking I concluded that it has to do ...
2
votes
3answers
87 views

Why cars have transmission gears? [on hold]

Cars need transmission to efficiently vary the speed of the wheels and this due to the fact that the internal combustion engines have a very limited torque band. What I don't understand is why ...
3
votes
1answer
70 views

Grooves on water tank

Why are there grooves on almost every water tank? Just typing water tank in Google images would reveal what I am talking about. And here is a sample picture! I think it would mostly be regarding ...
2
votes
1answer
43 views

What physics describe the way a waiter/ waitress is balancing his/her serving tray?

A waitress in order to balance his/her tray is continuously moving this tray up and down. Similarly if you want to balance a pencil by its tip on your hand, you move your hand up and down. Does ...
-1
votes
1answer
52 views

How two cars are getting at the same point of the road (obstacle, cyclist, another car parked on a small part of the road) in the same time? [closed]

You have an ordinary road, two ways. You are driving on the right part of the road and you see a person walking on the same part 400m away, you have to slow down or to accelerate because from the ...
7
votes
1answer
324 views

How do car rear-view mirrors work? [closed]

I wonder, how does a car rear-view mirror work? When there is a car behind me with high-beam, all I do is flip a tong at the bottom of the mirror to relax the lights! Are there two mirrors in it, ...
3
votes
1answer
52 views

Why do the black balls floating on top of the water surface form lattice strctures?

The phenomenon I'm asking about can be seen in this veritusium video. The balls were just dumped in randomly, and they are buffeted by wind and currents, so how do they settle into clean lattice-like ...
0
votes
1answer
73 views

Why do we have to switch off mobile phones during flight in airplanes? [closed]

During take offs the flight attendant makes sure that mobile phones are switched off (or maybe turned in airplane mode), why is that necessary? (I suspect that there is something to do with physics ...
0
votes
0answers
22 views

Dynamics Circular Motion

For circular motion to occur a centripetal force is required, in the case of a bicycle when turning; the where does the centripetal force come from since the force of friction is not great enough and ...
0
votes
1answer
51 views

Can we generate electricity by using rotation of wheel of a bicycle? [closed]

Can we generate electricity by using rotation of wheel of a bicycle ?
0
votes
0answers
29 views

Why symmetry leads to stability?

In the whole course of physics I observed a very common thing present around us which is symmetry. Symmetry leads to stability everywhere. For example:-Pauli's Exclusion principle tends to make the ...
1
vote
0answers
86 views

Why does a corner slow a car down?

Lets say we have a car, with power being given to maintain it at 100 km/h and about to negotiate a slight bend. As the car turns the corner, there is no change to the accelerator pedal, and no braking....
1
vote
2answers
56 views

Which force is responsible for attraction of very finely ground non sticky material around the nib of pen?

Consider some very ground pieces of a non sticky solid material and put it on a piece of paper but be careful that these pieces must be very finely ground (somewhat powdery material but should not be ...
2
votes
4answers
840 views

Why we can't write in air? [closed]

Why we always require a surface to write something? Why we can't write in air? I think that it is due to friction but I am not sure about it. Edit As per helpful comments and responses, I think ...
5
votes
2answers
179 views

What's causes the 'backspin' while sliding a pencil along a table? [duplicate]

I've always thought it was weird that pencils act like this: if one pulls their finger along the side of a pencil until it touches the surface below, the pencil is launched in the opposite direction ...
10
votes
3answers
1k views

Does tea made with boiling water cool faster than tea made with boiled (but still hot) water?

I always make tea with boiling water - not water that is almost boiling, not water that has boiled and stopped boiling a few seconds earlier - in my opinion, for the best tea flavour the water must be ...
2
votes
1answer
54 views

Why is the rudder of a ship shaped like a wing?

I don't understand why lift gives an advantage, it could be working the same even if it was just flat.
6
votes
1answer
110 views

Oscillation of Chocolate bar on soda [closed]

Why does a piece of chocolate bar oscillate in soda (i.e. floats then after a while sinks and vice versa)? What parameters does the period of oscillation rely on? Is there a specific formula that ...
2
votes
0answers
19 views

vibration and movement of electric appliance

So, what I am thinking about here is a cooking mixer placed into a bowl which is turned on and left moving on its own. The bowl is such that it does not topple nor the mixer falls out of it. Once the ...
1
vote
0answers
40 views

About the color [closed]

When I am reading my book keeping my head steady, everything is fine. But when I bend towards the right or left of the book, or the phone screen, things become darker (it happens more in phone screens)...
1
vote
0answers
37 views

Ordered arrangement of clouds [migrated]

I happened to take a photograph of a region of clouds ,and it seems to have a rather ordered arrangement ,if one looks towards the left of the image. Would there be a physical explanation for this or ...
6
votes
2answers
81 views

What causes the color difference of lightning flashes?

Some flashes of lightning are seen in a blue shade while some have a yellowish/orange appearance .What is the possible cause of colour difference?
27
votes
4answers
3k views

What causes the direction of lightning flashes?

During a lightning strike, the flashes appear as cloud to ground or cloud to cloud. Why is this the only manner of propagation? Why do the flashes not go upwards from the clouds into the sky?
2
votes
1answer
60 views

My hairs on my hand stand straight whenever I move my hand to TV screen and feel vibration and sound on TV screen

Whenver I try to reach my hands near the screen of my TV . My hairs on my hands get straight and more importantly I can hear and feel a sound and kinda vibration . Please mention if this sound ...
0
votes
2answers
44 views

Exact mode of evaporation

I am having a doubt regarding what is the exact mechanism of cooling during evaporation. At one place it is said that as surface water molecules evaporate it takes heat from surroundings and hence ...
175
votes
8answers
13k views

Why do we bend a book to keep it straight?

I noticed that I have been bending my book all along, when I was reading it with one hand. This also works for plane flexible sheets of any material. Illustration using an A4 sheet Without bending ...
4
votes
0answers
48 views

Apple shape with no gravity [closed]

Would the shape of an apple change if it grew with no gravity? I would expect it having a slightly narrower and deeper dent where the stem is attached but I cannot quite figure out how to estimate ...
4
votes
3answers
81 views

Condensed water inside a bottle

So, I noticed that in a closed plastic bottle (say only less than half full) little droplets of water were condensed on one side of the internal surface. That was the side exposed to sun rays. Why ...
2
votes
1answer
54 views

Do electrons in a flash of lightning oscillate between Earth and the clouds (or between clouds)?

In this video, around 2:24, one can see a flash of lightning that keeps the same form for a little time span. Does this mean that it takes a while before the discharge is complete (which I can't ...
0
votes
0answers
28 views

Does the temperature of a rapidly moving macroscopic object higher than its stationary state? [duplicate]

I learned that the average kinetic energy has $$ E_k = \frac{3}{2}\ kT. $$ But if heat is in essence molecular motion, then is a rapidly moving ball different with a still one?
2
votes
0answers
97 views

What are some common counterintuitive classical physics phenomena that you can think of? [closed]

Some ordinary and everyday physics phenomena are counterintuitive when first encountered. Examples: demo of moment of inertia of cylinders rolling down an inclined plane by prof Walter Lewin: https://...
-4
votes
2answers
97 views

Why do people not have gravitational attraction? [closed]

Gravitational theory says every thing that has mass attract each other. So why don't people attract each other and overlap
14
votes
1answer
599 views

Does soap repel water?

Yesterday when I was taking my bath, I scratched my soap bar a bit and threw that bit on the shower floor. There was a little amount of water on the floor where that soap bit fell. To my surprise, I ...
0
votes
0answers
45 views

Replace warm air with cold air

In summers i.e. now, my room has hot uncomfortable air in night,but outside air is cold 4-5 degrees Celsius colder than inside, my room has windows parallel to wind flow, so though wind flows in night ...
0
votes
1answer
85 views

Why microwave oven makes dried bread soft?

This is an old age trick: if you have some bread that became dried and you put it in the microwave few tens of seconds (10 to 30 for top results) you get a nice soft and warm loaf as if it just came ...
0
votes
2answers
57 views

Where in microwave ovens things warm faster?

I want my mug to boil as soon as possible and I prefer not to throw energy away. Where in microwave ovens things warm faster?
4
votes
1answer
93 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
votes
1answer
45 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.
0
votes
2answers
75 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 ...
0
votes
1answer
55 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?
19
votes
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
votes
1answer
59 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 ...