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

learn more… | top users | synonyms

0
votes
3answers
63 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 ...
13
votes
1answer
5k views

How do they measure the rotational speed of cricket balls?

The 2013 Ashes series (a cricket thing between England and Australia) are underway as of today and it seems they have a new (to me) gimmick. It appears that they are now able to measure almost ...
5
votes
1answer
59 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 ...
3
votes
1answer
56 views

Stagnant Air Deep Inside Vintage Mines

This is really a question more about mining ventilation than true "physics." I occasionally explore a southwest desert mine, but am aware of the hazards - typically passing over half a dozen vintage ...
3
votes
1answer
106 views

What ring weave disposition should be the most resistant against stabbing and/or how to determine it

In a website that I am studying so I can build a Chain Mail, I have found a page featuring a lot of different Ring Weaves to build them. I want to determine which one is the best to provide ...
2
votes
1answer
56 views

Is, in terms of sound, pouring water in a bottle the analogous of blowing into it?

When we pour some liquid in a closed container, for instance a jar or a bottle, we usually hear two (acoustical) noises: one is the classical turbulent (I guess white) noise, that in my view is ...
2
votes
1answer
70 views

The Egg Smashing Tournament

My cousins and I have a annual egg breaking tournament. First, each of us gets a hard boiled egg. Then, in a bracket tournament style, a pair of us face off in an egg breaking round: one person holds ...
2
votes
1answer
139 views

Understanding equation for force acting on stones skipping over water

I think I have a decent conceptual understanding of the forces at work when stones are skipped over water. My question pertains to this equation, $$ F = C_L\rho U^2S\sin({\alpha + \beta}) $$ which ...
2
votes
1answer
124 views

Why do some objects tend to change their axis of rotation while rotating?

This question struck me a few minutes back, I was at a table with a pear. It was more narrow than round.I proceeded to rotate this pear in one swift movement. It rotated for a few seconds, and ...
2
votes
1answer
87 views

Researching an automobile accident.Wondering if someone can help me as I never studied physics

I am trying do some independent research on a recent auto collision where the information released doesn't seem plausible based on the pictures that I have seen of the accidents aftermath. A ...
2
votes
1answer
122 views

Does a cooler, submerged in water, keep beer colder, longer?

Looking around the web, I see some submerged bucket-like things, without insulation, and some floating coolers, where the actual cooler is not submerged. Given that your water temperature is lower ...
0
votes
1answer
55 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. ...
0
votes
1answer
270 views

What is the fastest way to heat my car?

During the winter months I often have to drive in a cold car and I want to warm up as fast as possible. What is the best setting to put the air on in order to warm up the entire cabin in the least ...
-1
votes
1answer
402 views

How does the magnetic field get induced in car's tire?

I was amazed to see how my car's tire started attracting the nuts and bolts, how in the world did it induce the magnetic field? Never heard of such phenomena!!!
10
votes
0answers
248 views

Suntan: UV absorption vs daytime

I guess that these questions were being asked by many people on the Northern Hemisphere during this summer (and other summers) and someone may give a nice, coherent answer. The general question is how ...
6
votes
0answers
151 views

Why can I turn light red or blue by holding my finger up to it?

This is a difficult phenomenon to explain. Imagine you have an opaque object partially covering a very bright light source, for example, an object held up against the sky. The left hand diagram is ...
3
votes
0answers
51 views

3D movie optics mathematics

I get the idea that we use two polarized light sources and a parallax rendered film such that the objects seem to resemble true parallax in our eyes once it passes through the polarized glasses, but ...
3
votes
0answers
132 views

Why (and how) do foods stick to a pan?

We all (sooner or later) have noticed that foods relatively high in protein (especially those low in fat) are very prone to sticking to a pan, or in general to any non-specially-coated metal surface. ...
2
votes
0answers
80 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 ...
2
votes
0answers
41 views

Model of scattering in wet things

You know that clothes and some surfaces become darker when wet (covered in an earlier question: why wet is dark?), because of the disordered reflections or of the refractive index of water or ...
2
votes
0answers
66 views

Train construction-need of suspension

Suspension generally used to make ride comfortable. But rail tracks are smooth and even; intution says trains no need suspension. But they have it. Why do railway wagon/coach require suspension when ...
2
votes
0answers
71 views

Seashell occurrance

Sometimes, sea shells accumulate on the sea shore, but sometimes they will instead be dragged back out to sea. What are the main physical factors that determine which of these things will happen?
1
vote
0answers
67 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 ...
1
vote
0answers
74 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
vote
0answers
38 views

Is there any advantage to using simple syrup over just dissolving sugar and waiting a minute?

When making coffee, I want to sweeten it with sugar. Many coffee shops offer simple syrup which is essentially just a solution of water saturated with sugar. Obviously, this has the advantage that ...
1
vote
0answers
45 views

How different sizes of water bubbles behaves in space

I watched a YouTube video of Chris Hadfield talking about different preventive measure for spills in space station. He is using water to demonstrate spills in space station. At 0.24sec the initially ...
1
vote
0answers
247 views

Definition of spatial and temporal coherence in QM?

It is often said that lasers are spatially and temporally coherent. Is there a simple definition of spatial and temporal coherence in the language of quantum mechanics? More specifically, can these be ...
1
vote
0answers
44 views

How do we get a wave pulse and wave packet/train?

Ok, If a disturbance is localized to a small part of the space for a certain time we get a wave pulse and if the source is active for time greater than to complete a single pulse we get a wave ...
1
vote
0answers
141 views

Milk-First School

I have always been struck by the huge amount of different arguments about the issue: When you make a cup of tea, the milk should be poured first or added to the cup after the tea? Wikipedia, ...
1
vote
0answers
72 views

How do whitening toothbrushes work?

Certain "whitening" toothbrushes are sold and I was wondering about the mechanisms behind the tooth whitening process. I suspect this is related to the shape and arrangement of the fibres, probably ...
1
vote
0answers
121 views

Can I detect/measure strength of a FM radio wave using a Electro magnetic field meter?

I understand that an alternating current produces an Electro magnetic field . The strength of this magnetic field can be measured by measuring devices. What I wanted to understand is Are the FM ...
1
vote
0answers
95 views

Rotation motion like the number 8

I'm a college student majoring in culinology and I'm trying to find out the reason or method of the number 8 motion. Responses doesn't have to be in culinology examples, but that would be a great help ...
1
vote
0answers
319 views

Why is my ballpoint pen spatially temperamental?

I'm trying to write with a ball-point ink pen on a plastic[1] sandwich bag. When I try to write on some parts of the bag, no ink transfers to the bag: I can continue trying for quite a while in vain. ...
1
vote
0answers
113 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?
0
votes
0answers
42 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
0answers
60 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 ...
0
votes
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 ...
0
votes
0answers
29 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
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 ...
0
votes
0answers
64 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 ...
0
votes
0answers
78 views

Cloud chamber with normal ice

Is it possible to build a cloud chamber by using normal ice instead of the usual dry ice? The temperature for dry ice is about 200$K$ while it is about 270$K$ for normal ice.
0
votes
0answers
46 views

How can we describe or model the spread of ice during the freezing of the surface of a still lake?

Premise: I live in a place where it is unquestionably wintertime in every aspect of the phrase. I was driving down the street and I drove by a lake. There was a recent and sudden temperature drop ...
0
votes
0answers
55 views

Magnetic field of magnetic screwdriver?

I wanted to know what is the typical strength of the magnetic field generated by the tip of a magnetic screwdriver, but couldn't find it anywhere on the manufacturers' webpages. So I was wondering, ...
0
votes
0answers
49 views

Using Optic Lens to Simulate Distance

I have an actual scenario, where I have to align a particular electronic optical device to two objects in the distance (2-3 km away), forming a right angle at the point where the optical device is. ...
0
votes
0answers
63 views

What creates black streams in fountain-type fireworks?

For the New Year celebration of 2014, my nephews set off a series of fountain-type fireworks (as shown below). When one looks carefully into the shower of light, one notices that a fair number of ...