Applies to questions related to common objects and frequently experienced effects. Typically, these questions require explaining how the laws of physics are applied to a common situation, how objects work, etc.
2
votes
1answer
128 views
Do plastic shoes electrically insulate people from the ground?
I've read on the Internet that wearing plastic shoes doesn't allow electric charges we collect from our environment (PC, TV, appliances) to be earthed.
Is this reasoning correct?
0
votes
2answers
97 views
Stealing heat, or not?
Say I hook a 1KW steam engine to the steam heat in my apartment, and generate 1KW of electricity (the engine is 1KW mechanical, not 1KW thermal) from it, so I don't have to pay ConEd.
That means I ...
4
votes
0answers
122 views
Why does the milk frother on my coffee machine make so much noise?
I have a Sunbeam home espresso machine with a steam wand. The steam roars out straight from the end of the wand. When it's first placed in the cold milk it really screams! Once the milk has a bit of a ...
13
votes
1answer
245 views
Why is boiling water the second time more quiet than boiling it the first time?
First of all: This is a different question than Why is boiling water loud, then quiet?, although the answers might be similar.
When I wake up, I boil some water for a cup of tea. It happens quite ...
5
votes
0answers
179 views
Where to place a fan in order to cool a room the fastest [closed]
Imagine I have room that is very hot and it is colder outside. I want to cool it down using a fan.
Scenario 1
There is only one door. I have one fan.
Where should I put it and which way should it ...
1
vote
1answer
89 views
What are the optimal conditions to fuel your car?
I was filling my car earlier today, and noticed a sticker posted on the pump.
This pump dispenses fuel at a volumetric amount measured in standard gallons (231 cubic inches). It does not adjust ...
0
votes
0answers
79 views
How can I measure the calories consumed in daily activity? [closed]
From a nice question here:
How are the calories in food calculated?
I can roughly understand how people provide the data of calories in certain food.
However, I am still confused about 2 things.
1) ...
3
votes
1answer
107 views
How would one calculate the amount of water contained in a cloud?
So I was looking out the sky one day and I wondered how I would go about calculating how much water was contained in a cloud. I figured the following simple outline
1) We need to roughly know how big ...
2
votes
4answers
145 views
Is a flawless trick die possible?
Trick dice have been used in gambling and magic shows. These are dice that, when rolled, will land with a preferred number facing upwards. This makes the result of rolling the dice non-random.
I was ...
1
vote
4answers
308 views
Physics of a burning log of firewood
According to my knowledge, heat is nothing but the result of the vibrations of atoms and molecules. I guess this mean that in heating up a gas or liquid, we are increasing the rate at which the ...
0
votes
2answers
282 views
Center of gravity of vehicle and vehicle performance
I am interested to know how does CG of vehicle plays role in the Fuel economy and the vehicle performance. Does CG of vehicle has anything to do while accelerating of your vehicle. I am a student, ...
6
votes
4answers
335 views
What happens when we cut objects?
What is the role of the molecular bonds in the process of cutting something? What the one of the Pauli exclusion principle, responsible for the "hardness" of matter?
Moreover, is all the energy ...
6
votes
1answer
124 views
What is the angle at which water is splashed when a vehicle tyre rides in water on the road?
I would like to know the following:
What is the angle at which water gets splashed when I ride my vehicle through a water on the road?
How does angle of water varies with speed?
What is the relation ...
1
vote
1answer
328 views
What exactly is a Fluorescent lamp?
A fluorescent tube (home-based) works on the principle of discharge of electricity through gases, as far as I can tell (I don't know much about cathode rays or gas discharge)
What happens inside the ...
0
votes
1answer
146 views
Do arXiv links last for the forseeable future? [closed]
If I give someone an arXiv link, say http://arxiv.org/abs/0707.0118 , will this link last for the foreseeable future?
4
votes
2answers
337 views
Why does the higher of two medical IV bags empties first?
I'm a nurse, so my physics background is about that of a lay person. Please explain on that level. Ordinarily an Intravenous (IV) fluid bag is one liter. An IV piggyback is usually 2500ml. usually the ...
3
votes
1answer
116 views
Why do beverages taste different based on how cold they are? [closed]
Why does temperature effect the taste of beverages?
Specifically, how does the temperature for example mask certain tastes ie filtered vs unfiltered water taste very similar at colder temp and Is ...
0
votes
1answer
142 views
Why does the water-pressure of my shower fall if I hold the shower head high?
I live in a very old house - build 1902 - in the 4th floor in the city of Karlsruhe (Germany). I have a shower and the gas-heater for the water is in it:
If I hold the shower head over some height ...
3
votes
2answers
260 views
Why are coke bottles that much fizzier if you shake them?
We've all been there: you drop your bottle of soda at some point and when you try to open it, it bursts into foam.
My question is, then: why does shaking a carbonated drink make the dissolved gas ...
0
votes
2answers
275 views
Is there a physical reason steel balls are not suitable to play billiards with?
Steel is an elastic matter and is often used when demonstrating elastic collisions. We also make springs from it.
Due to these properties and for its relative low price, it seems obvious to me to ...
0
votes
0answers
69 views
How and where is the information which constitutes memories stored in our brain? [closed]
I am wondering if the information was stored as in computers, with a sort of condensators system, but this would imply a certain discretization, and seems to be too restrictive.
Therefore, how the ...
2
votes
2answers
380 views
A wobbly pan on an induction cooker, is it less effective?
According to the Wikipedia, one of the limitations of the induction cooker is that the bottom surface of the pot should be flat.
Accordingly, I commented on a question on Seasoned Advise, but I'd ...
1
vote
1answer
133 views
Physics of Fireworks
This evening I saw the 4th July classic Fireworks in San Diego, and I was wondering about the most physical picture of what was happening. Does anyone have a good way to explain the detailed physical ...
19
votes
3answers
552 views
Why wet is dark?
When something gets wet, it usually appears darker. This can be observed with soil, sand, cloth, paper, concrete, bricks ...
What is the reason for this? How does water soaking into the material ...
9
votes
1answer
780 views
Why does paper become transparent when smeared with oil but not (so much) with water?
When I smear oil onto a scrap of paper and rub it in, the paper becomes quite transparent; but when I attempt the same with water it doesn't as much. Why?
7
votes
2answers
217 views
Why is paper more frangible when it is wet?
My four-year-old daughter asked me why paper tends to fall apart when wet, and I wasn't sure. I speculated that the water lubricates the paper fibers so that they can untangle and separate more ...
4
votes
2answers
211 views
How can one feel cold without touching it?
Let me explain.
My shower is inconsistant in how hot it gets. Whenever I turn on the shower, I always put my hand really close to the water, but not touching it, so I can feel the heat radiate from ...
1
vote
1answer
295 views
What forces act on a person sitting in a chair with wheels when they push off another stationary object
What is slowing me down when I push off my desk?
What are the "Major" contributors? and
Does how hard I push with one hand (or with two hands) make a
significant difference?
4
votes
3answers
3k views
Why can't helicopters reach mount everest?
Is there a reason why people can't just take the helicopter to mount Everest? Why is it that helicopters can't reach that high?
0
votes
1answer
160 views
Physical Explanation of Being Able to “Think” [closed]
This may look like a philosophical question, but I'm looking for physical explanations (if there's any), that's is why I'm asking it here.
What is the ability of thinking? We are all creatures ...
0
votes
1answer
78 views
heat of a laptop when placed on a table, when placed on a pile of books and when placed on a bed [closed]
I heard somewhere that it is dangerous to place a laptop on a bed. The reason given was that placing the laptop on the bed blocks (assume that the laptop does not have sideway fans - it only has air ...
5
votes
1answer
184 views
What is the roaring in a roaring fire?
I was just starting a barbecue fire by blowing on the smouldering coals when I realised I had no idea what the sound was actually caused by. I can make the sound by blowing at almost any flame I can ...
1
vote
1answer
119 views
Is energy “destroyed” when walking?
Conservation of energy states energy can't be destroyed, but isn't energy used up when walking in a straight line? If your not walking up a slope, kinetic energy isn't converted to gravitational ...
0
votes
1answer
111 views
Is a low-current electrical arc harmful to humans?
I've heard that electrical flux non-destructive particle testing machines are considered safe because they use less than 2 amps. I have seen an arc created between two objects do considerable damage, ...
2
votes
2answers
163 views
Is it possible to have a self-balancing system?
I am trying to create a machine that moves on two points (Wheels or legs). Because of the extremely difficult nature of perfectly balancing the parts, I am wondering is there any way to create a ...
4
votes
1answer
670 views
Why does it spark when I push a plug in the electrical socket?
When I slowly push a plug into the electrical socket I can often see sparks. Can anybody explain why? Can this be possibly harmful for the devices I plug in?
5
votes
1answer
963 views
Why is boiling water loud, then quiet?
Water in my electric kettle makes the most noise sixty to ninety seconds before the water comes to a full boil. I have been fooled many times by the noisy kettle, only to discover that the water was ...
3
votes
1answer
166 views
Boiling when I plunge my french press?
Occasionally when I make coffee in my french press I experience something odd. It happens pretty infrequently but certainly enough to be curious about. I have the grounds ready in the carafe. The ...
3
votes
1answer
140 views
A practical deceleration question
My friend is a U.S. Army paratrooper. Today, through an unfortunate series of events, he was jerked out of a C-17 traveling at 160 knots by his reserve parachute. First-hand accounts describe it as he ...
2
votes
1answer
115 views
Work Done to click a mouse?
Is there any good research done to find out the work done in clicking a mouse button.
any link to that would be greatly appreciated.
P.S.
i am not too sure whether this question belongs here or ...
2
votes
2answers
115 views
Knots and strengh of a rope
I read a few times that a knot can reduce the strenght of a rope, but I can't understand why this happens. Can someone explain me what happens to a rope tied with a generic knot and stretched? Is ...
3
votes
1answer
118 views
Why does the bubbling of a soda bottle pulsate?
If I take a bottle of carbonated water and open the cap slightly to allow the gas to escape, there will be a sudden rush of bubbles foaming to the top of the liquid for a few seconds, then a partial ...
3
votes
4answers
553 views
Why would it be true that people with longer legs walk faster than ones with shorter legs?
When a person walks, the only force acting on him is the force of friction between him and the ground (neglecting air resistance and all). The magnitude of acceleration due to this force is ...
4
votes
2answers
234 views
Why do books have dog ears?
I googled the question and found no explanation. It seems that dog ears are inevitable (for paperbacks, notably) even if you've always been careful. From my experience, they are about equally likely ...
2
votes
1answer
2k views
How much is 1 electron-volt (eV)?
I am interested in knowing how much is one eV of energy. Everywhere I found are the technical definitions. Can anybody please tell me how much is this much energy. I need something which I can feel. I ...
4
votes
1answer
137 views
Why do rain waves form and what is their connection to the texture of the surface they're on?
When it rains and water flows down an inclined street, ripples may form that are carried along with the current. Here's a picture with an example of what I'm talking about
I'd like to know what the ...
1
vote
0answers
72 views
Is putting a charged balloon up to a neutral wall polarization AND temporary induction, or just polarization?
Is putting a balloon that is charged up against a wall and having it stick polarization AND charging by temporary induction, or just polarization?
9
votes
8answers
2k views
Why do ice cubes come out easier from top trays?
This is my "hey, I've noticed that too!" question for the week. If you stack two plastic ice cube trays with water in them in a freezer, the resulting ice cubes in the top tray will usually come out ...
2
votes
2answers
533 views
Please recommend a good book about physics for young child (elementary school aged)
I'm looking for a book that would be appropriate for an advanced elementary school aged kids (say, 6-11 YO) describing the basics of physics (or sciences in general) in entertaining way.
The ...
3
votes
0answers
95 views
Can you safely draw sparks from the nose of an electrified boy?
From Purcell's Electricity and Magnetism
A spectacular conclusion of one of the popular exhibitions of the time
was likely to be the electrification of a boy suspended by many silk
threads ...
