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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42
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5answers
3k views

What causes this pattern of sunlight reflected off a table leg?

My friend noticed an interference-like pattern around the table leg. However, we do know that interference patterns of sunlight produces rainbow colours. What seems to be happening here?
1
vote
5answers
19k views

Why does cold water weigh more than hot water in a fixed volume?

Take a bucket of hot water and the other bucket of cold water. Why does the bucket full of cold water weigh more than bucket full of hot water?
0
votes
1answer
27 views

Can vernier scale ratio be less than 1?

I came across a question (See Image) that states about two vernier scales The first vernier scale is the top-most figure in the image: It has 10 vernier scale division equal to 9 main scale division ...
1
vote
1answer
49 views

How to measure the mass and balance point of a human forearm?

I've been trying to find this out for about a month now. I'm usually met with humorous but not really helpful comments about chopping my own arm off. I'm preferably looking to do this on a budget ...
7
votes
1answer
642 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 ...
1
vote
2answers
52 views

Lamina Pendulum Experiment help

I've been tasked with researching ways to find the gravitational acceleration g and its uncertainty together with the moment of inertia and and the moment of inertia's uncertainty. I have figured out ...
1
vote
1answer
167 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?
6
votes
2answers
227 views

does a rocking kettle cause the water to boil more slowly?

When I boil water in the kettle on my electric stove, sometimes it rocks back and forth making an annoying sound at a frequency of about 6Hz. When that happens, I move the kettle slightly to make it ...
1
vote
1answer
239 views

Does the termination point(level) influence water flow from a pipe

I get water to my home from a nearby Tank A at a certain height above ground level. I have a 1" pipe through which I get this water to my home.. I leave this water into my well by connecting a 1" tube ...
0
votes
2answers
3k views

Potential energy from opposing magnets repelling each other with a gap of 1 mm

I have two powerful rare earth magnets, that are separated by a distance of 1 mm. I applied energy to bring them closer to each other, hence increasing the potential energy. Now, when one of the ...
10
votes
5answers
2k views

Milk or sugar first to maximize temperature of a hot cup of tea?

If there is a hot cup of tea and we were asked to add milk and sugar, which mixing order would make the hottest tea? I personally think that the order doesn't matter, since sugar wouldn't change the ...
0
votes
3answers
80 views

An experiment to show sound waves

My 6 year-old son asked me to explain the sound barrier. I think I'm ready to explain, but I wanted to know if I could add a little homemade experiment to show visually how soundwaves are generated. ...
0
votes
1answer
25 views

Why is this ice cloudy at the center and has a transparent layer?

This fell at my place during a hailstorm. I can not figure it out why it is like this.
1
vote
5answers
5k views

What happens when I place an ice cube into boiling water

My friend tried this experiment at home: She put an ice cube into boiling water. The water in the container stops boiling while the ice melts to water. My question: Why does the water stop boiling ...
0
votes
1answer
126 views

Why don't get I shocked in an electric shower if the resistance makes contact with water?

I've found this image that perfectly illustrates my shower. I've read somewhere that the resistance is insulated so even if it touches the water, it doesn't conduct. However, as you can see, the ...
0
votes
6answers
2k views

Why does the bathroom become hot after a bath?

I have noticed many times that whenever I enter into the bathroom just after someone else bathed the temperature inside it would be high. Is it that the body heat comes out when we pour a lot of ...
0
votes
2answers
41 views

Sound pitch of glass with water

I have a glass (made from glass) at room temperature. I poured very hot tea in it and started stirring. No extra tea is poured in the glass. When hitting the glass with the spoon, I noticed the ...
-1
votes
1answer
37 views

Why does this circuit work and the other doesn't? [closed]

if we connect the set up like this the bulb glows but if we connect the [right wire] to the [earth of the left] then the bulb [doesn't glow]. Why does that happen?
19
votes
3answers
4k views

How does paper make sound when it is torn?

We know that from our experience when we tear up a piece of paper, we can hear a characteristic sound. What is the underlying mechanism behind it? What do the dominant frequencies (edit: I don't mean ...
10
votes
5answers
11k views

Is coherent light required for interference in Young's double slit experiment?

In this Veritasium video, a home experiment is presented which appears to produce a very good double-slit interference pattern with normal sunlight. The experiment is an empty cardboard box with a ...
1
vote
0answers
39 views

Direct comparison of energy measurements for kids

I am planning a few physics & science sessions in the woods with 14 year-olds. The theme for one of the sessions is Energy, and my aim is to show them how gravity, solar radiation, wind (air ...
2
votes
0answers
33 views

Printing zone plate with laser printer

I tried to print my own zone plates on transparent plastic with laser printer with this generator. I prepared a lot of plates with different settings - focus from 4 to 60 cm, 3 wave lengths, etc. Yet ...
15
votes
3answers
8k views

Home experiments to measure the RPM of a pedestal fan without special equipment?

Is it possible to determine to an approximate degree, the revolutions per minute of a fan, for example a pedesal fan pictured below, without using some electronic/mechanical measuring device? One ...
5
votes
1answer
43 views

Ideas for extending Muon-Life-Time experiment?

Background: I'm teaching a lab experiment for measuring the Muon lifetime. The experiment is a big tube of scintillator attached to a PMT. The muon entering the scintillator generates a reading in the ...
2
votes
1answer
52 views

Which will dry faster? [closed]

Assume that you have a wet shirt that you have just washed. You squeeze of the surplus water that can be squeezed out. Method 1: 1)You iron the shirt for 5 minutes and then hang it out to dry out in ...
0
votes
2answers
21 views

Would a hybrid mixed medium balloon allow you to use less helium to lift equivalent weight?

Suppose you had two balloons, one inside the other (a inside b). Would filling balloon "a" with the 80% nitrogen/20% oxygen mix you find in the surrounding air at ground level, and then filling ...
1
vote
0answers
32 views

How to predict a flight distance? [closed]

I conducted an experiment by varying the stretch length of a rubber band (angle is always constant) which resulted in different flight distance. My teacher told me to find an equation/law to explain ...
0
votes
1answer
24 views

How to insulate static electricity

This is a follow up question to Extending the reach of a crocodile clip for Kelvin Water Dropper experiment. We have resolved the issue, but now we have the following cable (in the image) that ...
4
votes
2answers
121 views

Is a DIY neutrino detector feasible?

How long does a neutrino detector filled with distilled water need to be to pick up neutrinos from one direction at about the level of a distant star within our galaxy? Would an off the shelf ...
1
vote
0answers
13 views

portable battery packs for decorative lights

I a set of home decorative lights that is powered by a portable 2 x D cell batteries. Can I replace the current pack with a new pack that takes AA batteries
0
votes
2answers
61 views

Is the video “How to Reveal Subatomic Particles at Home”'s explanation of its experiment misleading?

https://www.youtube.com/watch?v=wN_DMMQEhfQ The video asserts that along the path of an electron or muon, a trail of condensation will appear. But from what I understand, if an electron or muon (both ...
1
vote
2answers
63 views

Coefficient of friction and practical experience of sliding

The classical model of friction has a coefficient of friction depend only on the materials, but not area, and the force proportional to the normal force and coefficient of friction. So a given object ...
0
votes
1answer
102 views

Why we cannot hear ourselves or speak in water

I've tried several times to shout when I'm inside the pool but have failed to make any sound. Nor am I able to hear anyone talking outside. Why does this happen? The frequency does not change and ...
22
votes
11answers
3k views

Backyard experiments to falsify the Flat Earth theory [duplicate]

I recently became aware that the flat Earth theory still exists in the 21st century, and has colored the views of a friend of mine. Roughly speaking, the tenets are: The Earth is a flat disk, with ...
0
votes
1answer
46 views

resistance of wires

i have an upcoming open investigation at my school on wire resistance, in preparation for it i want to find out if duct tape would effect the multimeter's readings. i need to connect wire to a ...
0
votes
1answer
68 views

Will throwing oil on snow help it melt faster (significantly)? [closed]

The main thing that melts snow is the sun. Indeed, without the sun, the air itself would eventually turn to snow. The problem is, the sun melts snow inefficiently. The sun emits radiation (a lot of ...
-1
votes
1answer
325 views

How to prove R value for insulation?

I ran some tests on different types of insulation. I heated water, and placed it into an insulated box. The temperature was recorded every minute, for the water, as well as the air. The insulation ...
0
votes
1answer
579 views

How does temperature affect magnets?

How does an increase/decrease in temperature affect: Strength of the magnet Polarity Other changes? I have made some research and I have found that increasing the temperature turns ferromagnetic ...
1
vote
0answers
44 views

Rain experiment failed. Why?

I tried to make rain with a bottle and a balloon but it failed. The bottle was small, only a couple inches wide and the threaded part that I had the balloon on was less than an inch. In particular it ...
4
votes
2answers
64 views

How to design a simple experiment about force and motion for young kid?

I am planning to demonstrate experimental validation F = m*a - but to a 4th stand. student. By now he understands velocity and acceleration well enough. I want to design this experiment using ...
1
vote
2answers
77 views

What will hapeen if we remove air from a pipe [closed]

At first i did not know if this relate to engineering or physics but i think it mostly relate for physics so i posted here. My question is what would happen if we have a pipe set vertically and have ...
5
votes
1answer
54 views

Will the speed of the wind produced by a fan increase continously to infinity with the propeller spin speed?

Imagine a scenario: On a stand, an $RC$ plane motor is mounted on a stand. The motor has a $8x4$ prop attached to it. In the theoretical model, if the spin of the motor can be increased infinitely ...
4
votes
3answers
72 views

Raw data acquirable from amateur astrophotography

What raw data can I possibly acquire from an 8" Classical Dobsonian Telescope, and a DSLR? Could anything eye-opening to amateur astronomers be computed or calculated first-hand with such equipment? ...
1
vote
0answers
29 views

Is it possible to make a capacitor of required specifications using aluminium foil? [closed]

I wanted to make a FM radio transmitter but I was not able to get a capacitor with the exact rating of certain micro farad and pF. But I live in a poor country and I can not find them in the local ...
1
vote
1answer
46 views

Creating airflow in a mini greenhouse [closed]

How do I create the best airflow for a mini victorian style greenhouse, that has a total volume of 80148.75 cm3? I leave the lid on top, which is a triangular prism in structure, open about 2.54 cm. I ...
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: ...
5
votes
1answer
189 views

Why does a stream of water behave like this when aimed against a spoon or into a glass?

I noticed while doing everything except the dishes that water behaves quite strange. These two things might be two different phenomenon, but the water acts in a similar way in both cases. Spoon and ...
7
votes
2answers
524 views

Patterns in laminar flow of tap water

This is a simple experiment that anyone can do at home. Open your tap so that the water maintains a laminar flow, and the cross section of flow is considerably thin. Place your finger 3-4 cm below the ...
485
votes
19answers
183k 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 ...
3
votes
3answers
150 views

Why didn't the glass break?

In the figure below, a needle has been placed in each end of a broomstick, the tips of the needles resting on the edges of filled wine glasses. The experimenter strikes the broomstick a swift and ...