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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2
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0answers
163 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 ...
6
votes
1answer
456 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
9k 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
81 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
976 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 ...
3
votes
0answers
169 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 ...
4
votes
2answers
199 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
180 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. ...
3
votes
0answers
117 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
1k 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?
5
votes
1answer
610 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 ...
6
votes
4answers
7k 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
169 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
368 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
3k 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 ...
3
votes
1answer
344 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
876 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 ...
22
votes
1answer
3k 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 ...
0
votes
2answers
1k 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 ...
13
votes
4answers
4k 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
571 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 ...
20
votes
3answers
31k 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 ...
5
votes
1answer
923 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
143 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
456 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
131 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
483 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 ...
23
votes
2answers
720 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
1k 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
282 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
3k 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
57 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
218 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
266 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
240 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, ...
3
votes
1answer
446 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
225 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 ...
3
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
1k 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
523 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
2k 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
360 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, ...
19
votes
3answers
3k 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. ...
7
votes
4answers
926 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
410 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 ...
1
vote
1answer
668 views

Heat absorbed by a room

How can one calculate the amount of heat absorbed inside a room in a single day using the temperature readings of the day? If the temperature has to be reduced from 30C to 20C how much heat should be ...
2
votes
2answers
4k views

Microwaves vs Gas or Electric Coil heating of a water boiler in a typical household

Wouldn't it be more energy efficient and or safe to use microwaves to heat our home's water boiler instead of using dangerous gas or hot electric coils that could catch other things on fire? I'm kinda ...
0
votes
2answers
129 views

static shock=thermocouple?

I used to live in Boston. Near my complex, there was an apartment complex with lots of our friends. Anyways, that place had faulty heating most of the time; mainly in the corridors. They were pretty ...
1
vote
0answers
97 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?
5
votes
5answers
8k views

Why does hot oil explode when pouring water on it?

I am puzzled to know, What is the reason of hot oil make sound and explode when we pouring water on it?