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.
8
votes
3answers
666 views
Is it possible to reproduce Double-slit experiment by myself at home?
I want to reproduce this experiment by myself. What I need for this. What parameters of slits and laser/another light source it needs? Is it possible to make DIY-detector?
11
votes
6answers
1k 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 ...
1
vote
0answers
24 views
Easy to do experiments that clearly show outstanding properties of graphene
By chance we received for free some monolayer graphene sheets (20 cm x 20 cm) and mixed coper-graphene wires at our University. I would like to prepare some very easy to do experiments for the ...
0
votes
0answers
24 views
What are some novel physics demonstrations that can be done cheaply? [closed]
I have a physics demonstration assignment for high school, and I was wondering if you had any ideas for demonstrations that could be done on a tight budget?
4
votes
1answer
82 views
Physics of every-day life: rotating bag of tea
Whilst studying for my physics courses, I like to drink tea. Today, I noticed that if you pull a bag of tea out of a hot cup of water, it gradually starts to rotate, picking up speed as time ...
1
vote
0answers
77 views
Easy question about magnetism?
I have to build a simple electric motor by attaching a magnet to a battery, extending the terminals of the battery (with stiff wires so they could act as supports), and placing a coil of wire on top ...
2
votes
1answer
56 views
Is it viable or possible to make your own transistor?
Just wondering if it is possible/viable to construct your own transistor, not small like todays, but the same scale as the one created at Bell Labs.
5
votes
3answers
1k 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: ...
-8
votes
0answers
42 views
not all items fall at the same rate some items have outside facters gain speed in which they “fall” [closed]
I was reading one of the post this morning and found it fasanating with all the formulas that were being poured out about items will falling at the same rate given the same hight that they were droped ...
5
votes
3answers
221 views
How can I determine the coefficient $k$ in $ \dfrac{dT}{dt} = -k(T - 100 \mathrm{^\circ C}) $?
I recently spend some time on cooking and I'm curious about the time evolution of the temperature of the water. I did some experiment and the temperature is of the form
$$ T = 100 \mathrm{^\circ C} + ...
1
vote
0answers
52 views
Calculate how hot PLA will become
I am trying to attach the shaft of a brass heating tip to a PLA component. My problem is that the tip will have to reach a temperature of about 200°C and the PLA can only handle a temperature of about ...
160
votes
19answers
55k views
Cooling a cup of coffee with help of a spoon
During the breakfast with my colleagues, a question popped into my head:
What is the fastest method to cool a cup of coffee, if your only available instrument is a spoon?
A qualitative answer would ...
22
votes
6answers
2k views
How do whisky stones keep your drink cold?
From a discussion in the DMZ (security stack exchange's chat room - a place where food and drink are important topics) we began to question the difference between how ice and whisky stones work to ...
2
votes
1answer
49 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 ...
2
votes
0answers
54 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 ...
0
votes
0answers
93 views
Keep my salad cold in the microwave [migrated]
Okay. I have a plate with chicken and salad. I want to heat the chicken, but keep my salad cold.
I'm looking for a list of food-safe materials that can keep food from heating in microwave.
6
votes
2answers
123 views
Must a vertical sundial face exactly South?
I am a sundial. I'm prepared to bet
Your watch can't tell when the sun will set
I once heard Frank King talk about sundials in particular this very cool one, which measures Babylonian hours ...
3
votes
1answer
105 views
Michelson–Morley @ Home
The Michelson-Morley experiment seems to have taken many years, resources and a nervous breakdown to complete.
Is it possible to recreate a variation of this experiment at home for say, under $1000, ...
2
votes
3answers
672 views
How to make a small tokamak?
$\require{mhchem}$I made a fusor once, like the easy science project: deuterium-deuterium ones, but they're really inefficient. I was wondering if it would be possible to make a small tokamak; not one ...
3
votes
2answers
4k views
How do you magnetize an object?
How can I go about magnetizing something? Specifically, a whole bunch of BB's. I want to try this so that I could make a cheaper version of the Bucky Balls product. Even if I can't replicate Bucky ...
1
vote
1answer
64 views
A good theoretical approximation for a magnetically damped pendulum
In a laboratory course we had to perform an experiment with a pendulum (just an iron weight on a wire) and play around for some time with its wire's length and so on.
This was quite boring and we ...
3
votes
1answer
81 views
How to create visible reflections in shallow water?
Assumption: The only lights I have are candle, table lamp, and sunlight.
What would I need to create visible reflection of an object in the shallow water contained in a 5 liter bucket? Is it even ...
8
votes
3answers
527 views
How hot is the water in the pot?
Question: How hot is the water in the pot? More precisely speaking, how can I get a temperature of the water as a function of time a priori?
Background & My attempt: Recently I started spend ...
4
votes
3answers
1k 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?
5
votes
1answer
91 views
Whistling on bottle tops
It is well known that if you blow horizontally on a bottle top it creates a sound. Pouring water to the bottle changes the pitch.
I have been doing experiments on the relation between the sound's ...
2
votes
3answers
434 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 ...
1
vote
1answer
69 views
Why do CD's shatter in a microwave?
Why have I heard that eggs and CD's and DVD's explode when microwaved?
1
vote
1answer
90 views
Demonstrating Quantum effects with home experiments using green diode laser [closed]
I would like to preform home experiments to demonstrate quantum effects to my kids. I need a list of experiments on Laser photons that could be easily conducted at home to demonstrate quantum ...
-1
votes
1answer
80 views
Funny classroom experiments [closed]
I'd like to perform some weekly classroom experiments to keep my students interested and curious about everyday physics. Those experiments have to be quite easy to set up and not too easy to ...
17
votes
3answers
5k views
Why does the water rise?
It's a very popular experiment (eg), from elementary school : put a burning candle on a dish filled with water, cover the candle with an inverted glass: after a little while, the candle flame goes ...
0
votes
0answers
74 views
Superconductors for sale? [closed]
Does anyone know where I can purchase superconductors for a school presentation? I don't need a whole kit, just the disk itself. Thanks.
0
votes
1answer
162 views
Experiment to measure initial speed of high speed tennis ball?
I want to devise a way to measure the initial speed of a tennis ball fired from a tennis ball cannon, but without using any speed-measuring devices. Just plan distance-measuring and physics formulas.
...
1
vote
5answers
544 views
Parallel circuits - Overall resistance decreases with additional resistor
Let's say that there is a parallel circuit with two identical resistors in parallel with each other. If a third resistor, identical to the other two, is added in parallel with the first two, the ...
9
votes
7answers
3k views
Why is a 1mW laser dangerous?
In our Physics lab we have a 1 milliwatt (0.001W) helium neon laser. Despite the low power, we were cautioned not to even look at reflections of the beam as it could cause permanent eye damage - why ...
5
votes
1answer
134 views
Practical method to weigh human limbs with common household items?
What methods could be used to determine (or estimate within a reasonable margin of error) the mass of a living human's limbs, short of cutting them off? And more interestingly, how can this be done ...
16
votes
3answers
1k 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.
...
1
vote
3answers
90 views
How to design an experiment that shows that a rectangular pulse can be expressed as a series of infinite sinusoids?
Is it possible to design a physical experiment that shows that a time limited signal, such as a rectangular pulse is composed of infinite continuous sine/cosine waves?
1
vote
1answer
147 views
Force exerted on a cone
This is probably a pretty elemental question, but I can't figure out what the concept is called or how to calculate it. Say you have a solid cone shaped piece of ice, you hold it in your hand and ...
5
votes
2answers
113 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
96 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
2answers
115 views
Room temperature and fan orientation
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 ...
4
votes
4answers
396 views
How would you design an experiment to grok optical phenomena?
I've been toying with the idea of making a 3D scanner that uses an IR distance sensor to find position vectors of an object in space and then translates that into a 3D computer model.
One of the ...
3
votes
1answer
162 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 ...
8
votes
4answers
748 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, ...
15
votes
2answers
404 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 ...
0
votes
0answers
201 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
1answer
99 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 ...
4
votes
1answer
72 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 ...
3
votes
0answers
90 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 ...
3
votes
2answers
83 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 ...
