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.

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6
votes
3answers
149 views

Can we detect whether food has previously been heated in a microwave oven?

An acquaintance told me that she refuses to eat microwaved food because she read that the microwave changes the molecules of the food somehow. Her statement is vague and her sources are dubious but I ...
3
votes
2answers
60 views

Squinting at light sources

I am sure it's just your eyelashes creating a filtering effects, but if you look a a bright(ish) light source such as a lightbulb while squinting, if looks like you are seeing straight light rays ...
11
votes
1answer
2k 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 ...
3
votes
1answer
99 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
85 views

Where is the basketball event horizon?

I'm watching a lot of basketball this month. A common event is the ball going part way into the hoop and then coming out again. Announcers sometimes claim that the ball was "halfway through" when it ...
-1
votes
1answer
92 views

Heat preserving performance of container relative to content

This question has been addressed in the case of a thermos bottle: Performance of a thermos bottle relative to contents I am asking the question again without the hypothesis that it is a thermos ...
-2
votes
1answer
110 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!!!
6
votes
0answers
60 views

Branching lemon drop “smoke rings”

This might be hard to ask, but here goes nothing. I recently poured a cup of water into a black coffee cup. There was a light source--not very bright--above the cup. Anyways, I was squeezing a ...
5
votes
0answers
131 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 ...
5
votes
0answers
370 views

Why is it hard to breathe when cycling against the wind?

Sometimes when I bicycle against hard wind, I find it difficult to breathe. Others I have discussed it with have also noticed this effect. A possible related phenomenon that I heard from an ...
3
votes
0answers
108 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 ...
2
votes
0answers
36 views

Is it possible that a battery goes flat faster in a cold environment?

I own an old iPod Classic with original lithium-ion polymer battery and I use it primarily while running. Recently I discovered that when a temperature outside is low, usually below 5 C degrees, the ...
2
votes
0answers
63 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
27 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
41 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
55 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 ...
1
vote
0answers
213 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
90 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
17 views

How do you calculate the air and water pressure inside the bell siphon during and after the vacuum is formed?

I am interested in the math/physics behind the simple bell siphon. In this YouTube video, the presenter says that the space in the top of the bell becomes a vacuum when the water flow eventually fills ...
0
votes
0answers
33 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 ...
0
votes
0answers
83 views

Working of a vertical axis wind turbine

Conventional horizontal axis wind turbines use lift force generated in the blades to turn a turbine. But what is the mechanics of vertical axis wind turbine? What would be the free body diagram of ...
0
votes
0answers
67 views

When to dump water from a water cooler

If space in your cooler is not an issue and you're not concerned about other issues associated with water collecting in your cooler, under what conditions should you dump water from your cooler if ...
0
votes
0answers
2k views

How to determine size of a Heat Exchanger?

I am designing a Tube heat-exchanger, similar to this: My process requires water (at room temperature, 18C ~ 22C) that is being pumped out of a small tank (300 Liters) to be heated in a ...