questions concerning measurements, experiments, and activities that demonstrate physics and are safe to do at home, require at most one tool or ingredient not readily available, and can be interpreted or analyzed on one sheet of paper with accessible math.

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6
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2answers
534 views

Is it cheaper to boil water on high gas heat or low gas heat?

Assume my time value is \$0. High gas heat adds more energy per second to the water but the pot may absorb the heat less efficiently, or maybe the shape of the flame is less good, or for other reasons ...
3
votes
2answers
385 views

Do I need to have an airtight container to siphon boiling water?

I'm attempting to siphon boiling water into another container for a school project. I have researched the physics of a siphon but I can't seem to make my boiling water siphon out of its initial pot. ...
4
votes
3answers
824 views

Room temperature and fan orientation [duplicate]

So I'm in a tiny dorm room and I normally point my fan blowing outside the window to cool my room off. I've been in some debates on blowing air out or in is more effective, so I'm hoping to get some ...
3
votes
1answer
669 views

Revealing Electric field lines through Grass seeds in mineral oil

In one of Walter Lewin's famous lectures, he takes a small container almost completely filled with mineral oil and grass seeds (I'll keep looking for the video to link to it). He connects two ...
-1
votes
1answer
729 views

How much pressure is needed to break an egg if applied from top and bottom?

Everybody knows that you can't break an egg with our fingers when pushing from top and bottom. I assume if we could squeeze hard enough the egg would break?
2
votes
0answers
209 views

How can I determine the type of magnet used in a DC motor?

I repair electrical motors in a workshop and sometimes I must repair permanent magnet DC motors and other motors that use permanent magnets. I need to specify type of permanent magnet (Ferrite or ...
8
votes
1answer
1k views

Can you tell just from its gravity whether the Moon is above or below you?

If you are on a place of Earth where the Moon is currently directly above or directly below you, you experience a slightly reduced gravitational acceleration because of Moon's gravity. This is what ...
9
votes
4answers
17k views

What happens when you heat vodka in a microwave?

Since ethanol has a lower dielectric constant than water would the water heat up and boil before the ethanol? Would the water transfer heat to the ethanol and, since ethanol has a lower boiling point, ...
4
votes
1answer
95 views

Can I find the frequency generated by tapping a battery on a coin?

According To How Stuff Works , if you tap a 9 volt battery on a coin it will transmit Radio waves. I was wondering, because I don't have a radio with me at the moment, Is there a way I could discover ...
2
votes
3answers
1k views

Apparent paradox in equation of continuity

Equation of continuity says us that if we insert some fluid in a tube, the same amount of fluid will come out from the other end. If we make a small hole in a hose pipe, water will come out with a ...
4
votes
2answers
346 views

Why is a washing machine unable to spin-dry a duvet?

Background story: I put my duvet (synthetic filling) into a washing machine, and the machine was unable to spin-dry it. My mom told me: "It's because it is full of air". I was not satisfied with the ...
5
votes
2answers
281 views

Why don't Microwave ovens use more energetic EM radiation?

Because in theory, visible light contains more energy than the microwaves actually used to cook your food. 1) Does it have to do with resonance frequency of the $H_2O$ molecule? 2) How can ...
0
votes
1answer
341 views

Charging using a CRT TV set

I was doing an experiment with my CRT TV where I put aluminum foil on the screen wire it to a can and open the TV and a ring between 2 can will swing if I ground the other can. http://scitoys.com/...
3
votes
0answers
159 views

Thermal imaging camera [closed]

I'm making a tea bag experiment (Make a hollow cylindrical tube from light paper e.g. from an empty tea bag. When the top end of the cylinder is lit, it takes off.) I need to know how hot air is ...
2
votes
2answers
3k views

Liquid with freezing point above 0 Celsius that could be use at ice rinks

Please help me with an answer to my dilemma: Is there a liquid that could be used to fill an ice rink (non-explosive, non-poisonous, etc), and have the freezing point above 0 Celsius?
6
votes
1answer
991 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 ...
10
votes
3answers
14k views

Rough, easy DIY method of measuring magnetic field strength

How to easily, using standard DIY equipment measure the strength of magnetic field generated by a permanent magnet? Narrowing down the "loose language" of the above: strength of magnetic field: ...
1
vote
1answer
174 views

Metal rod between a capacitor

In my experiment, I am filling liquid crystal between two glass plates. Nn AC voltage is applied on them. The thickness of the liquid crystal cell is around $200 \mu m$. One glass plate is with +V and ...
3
votes
2answers
487 views

Most sophisticated experiment you could perform in your garage? [closed]

What are some of the most elegant/complex/sophisticated physics experiments one could perform in his garage, if he has enough spare time and technical/theoretical know-how, but a relatively limited ...
5
votes
1answer
6k views

If 1 screw can support 120 lbs, how much weight can 25 screws support?

While this is mainly about my personal home improvement project, I figure this would be a good opportunity for some of you to apply your physics skills to a real-world situation. My situation is this:...
4
votes
1answer
679 views

Home-made Shock diamond

Is there any way of creating a "home-made" effect of shock diamond phenomenon that I could take a picture of? If so, How could I make one?
3
votes
3answers
1k views

How to measure force of impact inside container?

I am in 7th grade and for my science fair project, I need a way to measure the force on a dropped object when it hits the ground. What I am trying to determine is which packing materials provide the ...
23
votes
1answer
8k views

Energy in bolognese reduction - lid on or off?

Generally, to let my bolognese thicken, I leave the lid off in order to "let water vapor escape." I am however distracted from enjoying the taste because I'm having doubts that my physical reasoning ...
1
vote
2answers
3k views

Inductance - Sign convention problem…

My problem is with a circuit containing a resistor of suitable resistance $R$ and a solenoid. At time $t<0$, there was a battery that created a current in the circuit and at $t=0$, the battery is ...
16
votes
4answers
7k views

Tried to do the double slit experiment, failed. Why?

I tried, and failed, to do the double-slit experiment. I thought I had a good experiment setup, but obviously I was wrong. Can anyone offer some insight in what I might have done wrong? Most of ...
3
votes
1answer
1k views

Does a microwave resonantly excite the rotational levels when cooking?

Wikipedia states there is no resonance absorption, but says at the same time that the molecules are oscillating like dipoles, which is kind of the same if you are exciting the rotational levels ? The ...
47
votes
4answers
88k views

Why do grapes in a microwave oven produce plasma?

Some of you may know this experience (Grape + Microwave oven = Plasma video link): take a grape that you almost split in two parts, letting just a tiny piece of skin making a link between each half-...
5
votes
1answer
2k views

Are coffee's properties different enough from water's to cause increased spillage while walking?

I recently found this article, which describes how... It just so happens that the human stride has almost exactly the right frequency to drive the natural oscillations of coffee, when the fluid is ...
6
votes
2answers
247 views

Handling halogen lamps

When consulting manuals, electricians, online sources, etc., they always instruct you to handle halogen light bulbs with gloves. The "explanation" that usually accompanies this statement is that oils ...
0
votes
2answers
813 views

Hanging a Hammock

I have a hammock that I want to hang using a tree on one end and a wooden post set in a bucket of cement on the other end. How would I determine how heavy the cement needs to be so that it would ...
0
votes
1answer
157 views

Find the real height of an object by eyes

I wonder if I can get the height of an object (tree or a building) with the knowledge of: The distance between me and the object? The apparent height of that object?
2
votes
2answers
603 views

Demonstrate magnets adhere to conservation of energy pursuant to the laws of thermodynamics

I am looking for a way to demonstrate that magnets adhere to the laws of thermodynamics, in particular the requirement that energy in a closed system be conserved. To adhere to the requirement that ...
28
votes
2answers
999 views

Why does laser light not affect glowing materials?

I have this childrens rubber ball which glows in the dark after it's exposed to light. I "charge" it with a flash light then play with my dogs at night. I thought to try a very intense green laser, ...
19
votes
2answers
2k views

Why does the note played by a flute not change in this case when the air column is interrupted?

I play the flute as a hobby, and I've noticed that when playing middle D or E flat, one can interrupt the air column by releasing a certain key (which is near the middle of the air column), and yet ...
3
votes
4answers
327 views

List of Physical Toys [closed]

There should be a list of toys considered "physical", which demonstrate or make you think over certain physical principles/phenomena. And of course which could just amaze. Related question at MSE is "...
9
votes
6answers
5k views

Simple Experiment to Demonstrate Special Relativity

I am trying to think of a good experiment that can be done for under $250 or so that would demonstrate some aspect of Special Relativity. Ideally this will be done in a few years with my kids when ...
0
votes
1answer
61 views

Does water in the drain follow the distance-squared rule of force?

When I shower I notice that the soapy water spinning around the drain often takes the form of a spinning galaxy, complete with spiral arms. Does this indicate that the water's speed around the drain ...
7
votes
3answers
281 views

What's the most efficient strategy to shake a bottle to create a global flow?

Consider a bottle of orange juice with pieces of the fruit gathered at the bottom of the bottle. You need to shake the bottle to evenly distribute the pieces in the bottle. The first part of the ...
1
vote
3answers
314 views

Quantum experiments in the pre-industrial era

Could an 18th century or earlier scientist have come across phenomena which require quantum theories to explain them, given the apparatus available at the time? I'll choose 1805 as the cut-off date, ...
3
votes
3answers
279 views

What are some creative illustrations of the nature of dissipative forces?

I'm teaching a conceptual introduction to physics for American 13-15 year old students this summer. One of the main ideas I want to hit on is the relationship between energy conservation, equilibrium,...
3
votes
1answer
625 views

Enhance a home build spectrometer

I would like to build a home made spectrometer like it's describing here: http://coolcosmos.ipac.caltech.edu/cosmic_games/spectra/makeGrating.htm How can I improve this spectrometer? A prism from an ...
0
votes
1answer
403 views

What could I test for in a guillotine? [closed]

I'm doing a school assignment project and I need to investigate something of my choice. I was thinking of doing something about how the height and angle the blade of a guillotine is dropped from ...
4
votes
3answers
5k views

Solar Eclipse Viewing

I know it is not safe when viewing a solar eclipse to look directly at the sun. I know you can purchase solar eclipse glasses online but how do you make your own solar eclipse glasses that are safe to ...
3
votes
2answers
2k views

Conservation of angular momentum in helicopter

I have a small RC-controlled toy helicopter with removable tail rotor. Suppose I remove the tail rotor, hold the tail with my hand, start the rotor until it moves with constant angular velocity and ...
2
votes
0answers
703 views

Why does a coin falls faster when it's flipping as well?

From my experiments with measuring how fast a coin falls, I have consistently measured a faster falling rate for a coin that flips as it falls. As an example, a coin dropping on its edge from height ...
3
votes
1answer
3k views

Why is the lid of the cookware kept on induction cooker not hot?

Induction cookware cooks food by inducing an electro magnetic field in the ferro-magnetic cookware. Since iron offers a lot of resistance to the current, the current is converted into heat in the ...
1
vote
1answer
550 views

Per unit area, is there more heat transfer through the open top of a mug or the side walls?

I had a mug of hot coffee cool too rapidly for my liking the other day, which made me wonder what was the greater contributor to heat loss for a typical open-top ceramic mug: the open top, the walls, ...
21
votes
3answers
5k views

Why does the sound pitch increase on every consecutive tick at the bottom of a filled cup of coffee?

Since I don't know the proper physical terms for this, I describe it in everyday English. The following has kept me wondering for quite some time and so far I haven't found a reasonable explanation. ...
8
votes
4answers
1k views

Astronomy Experiments for Amateurs

Are there any resources online for astronomy experiments that I can perform myself? I am looking if anyone knows any measurements to take while looking for various objects during the evening ...
1
vote
1answer
709 views

Are there good home experiments to get a feel for the behavior of yield-stress liquids?

What common household liquids / foodstuffs show Herschel-Bulkley fluid behavior? I assume tomato soup to be one, since when sloshing it around lightly on a spoon the visible surface moves as one (as ...