Questions tagged [physics]

A puzzle relating to physical equations or physical principles such as energy, entropy, and classical/quantum mechanics. General physics questions are off-topic here but can usually be asked at Physics Stack Exchange.

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5
votes
5answers
375 views

A Simple (High School Science) Question

Let's say you have a pot with some water in it (as shown). Then you take an empty glass and put it upside down (its mouth on the flat pot bottom) in the pot. What can happen with this experiment? Four ...
6
votes
1answer
260 views

A very familiar object

I'm sure you all have held a common retractable, spring-loaded pen at least once, and that many of you have tried to make it jump vertically by first pushing it downward against a table to load the ...
7
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2answers
522 views

Scientifically Themed Dingbat/Rebus Puzzles - Part 5

Previous ones here: part 1 part 2 part 3 part 4 To reiterate, the media is reasonably well known, so if something has barely any views on YouTube, for example, it's probably not the intended answer. ...
7
votes
3answers
434 views

Scientifically Themed Rebus/Dingbat Puzzles - Part 4

The same basic idea (I have a lot of these): science-styled expressions that represent some popular media. Previously, some guesses were for things I would say aren't that well known, so keep in mind ...
4
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3answers
338 views

Scientifically Themed Rebus/Dingbats - Part 3

The same idea as before: the "scientific" expressions represent some form of popular media. Enjoy. Part 1 Part 2
12
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2answers
752 views

Can anyone help poor Fblthp?

my name is Fblthp, and I am completely lost. I don't know the location of my home planet, and given the barriers in language and culture, I can't tell you its name in any meaningful manner either. The ...
6
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1answer
306 views

Scientifically Themed Rebus/Dingbat Puzzles - Part 2

below are more rebuses with "scientific" expressions that represent something in popular media. Part 1 here. One of the questions in Part 1 has a link to a question here.
8
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4answers
821 views

Scientifically Themed Rebus/Dingbat Puzzles

Below I have created a list of a few "scientific" expressions that represent some form of popular media, with the type stated. Hope you enjoy.
1
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2answers
115 views

Triangular pool and three swimmers [closed]

Given a triangular pool 100, 120, 140 yards and three swimmers which swims at rates of 3.5, 4.0, 4.5 yards per second - place them on the edges of the pool in such way that when they start swimming at ...
1
vote
0answers
114 views

How Do You Prove That This Puzzle Is Physically Solvable?

https://www.reddit.com/r/BeAmazed/comments/fyt7x9/it_seems_to_be_impossible_but_it_gets_done/?ref=share&ref_source=link The goal of the puzzle is to remove the wooden stick from the jar by ...
12
votes
0answers
414 views

Unused By Only Three

First, beg for the most positive among the stables. Now you can do the second, beg for the independent. Now you can do the third, beg for the overlappable. Now you can do the fourth, beg for the ...
11
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2answers
2k views

Two Cannons - A Beginner's Physics Puzzle

Standoff Let's say we have two cannons aimed directly at one another ( as my horrible attempt shown in the image ). The Angles The cannon on top is aiming down towards the one on bottom right, and ...
1
vote
0answers
86 views

Why does the boiler in Riven drain when the rubber hose is disconnected? [closed]

This question has spoilers for Riven, since it requires explaining one of the puzzles in the game in some detail. In the 1997 puzzle adventure game, Riven: The sequel to Myst, one prominent puzzle ...
5
votes
1answer
90 views

Three mini-crosswords with maths/physics theme

Three mini-crosswords are presented below. There is a maths/physics theme to these puzzles. I am sure that they will be solved quite quickly and hints will not be required, but if anyone gets really ...
11
votes
1answer
276 views

Clever Collision Counting

A mass of 1,000,000kg is sliding in from the right on a friction-free, level surface. It has a perfectly elastic collision (collision 1) with a stationary 1kg mass. To the left of the 1kg mass is a ...
4
votes
1answer
95 views

You can see me but you see through me

This is my second (easy) riddle: You can see me but you see through me. I can fill the room but I will vanish as soon as nobody creates me. I transport energy but I am not sure if I am made of ...
6
votes
7answers
4k views

If the second hand goes backwards, starting from 12:00, how long does it take to meet with the minute hand?

If the second hand of a clock goes backwards, starting from 12:00, how long does it take until it meets with the minute hand (which is going forwards)?
4
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1answer
198 views

Traffic lights in space

In a distant future, human beings are travelling between planets and even solar systems with ease. Their advanced technology allows them to drive their own space-cars, which have a cruising speed of ...
19
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6answers
4k views

The falling broom handle

As the reaction to my previous physics puzzle was somewhat mixed, I'll try again. I found this in an online physics book. You hold a broom as shown in the following picture: The head of the broom is ...
15
votes
3answers
2k views

A pencil in a beaker of water

You have a beaker containing 100ml of (slightly salty) water, standing on a digital scale. The scale has been calibrated to the beaker so that it shows only the weight of the water, which is exactly ...
-2
votes
1answer
96 views

Distance between two friends [closed]

Two friends are 200 meters apart in a concourse. They then both walk 100 meters each with their faces towards to each other. Yet after this 100 meter walk they are still 200 meters apart.
4
votes
0answers
116 views

Run to a point in a triangle in shortest time [closed]

This is a generalization of a puzzle that dealt with an equilateral triangle. Assume three runners with the following speeds - 4.5, 6.2, and 8.7 meters/sec. They are at the corners of a triangle with ...
3
votes
3answers
206 views

Two Identical Pistols Shot Simultaneously [closed]

Two identical pistols are shot at the same moment, one in Death Valley and the other the Schwarzwald Germany. Both of them are at targets 40 meters away. Which one hits its target earlier?
30
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8answers
4k views

Pulling the rope with one hand is as heavy as with two hands?

There is this box, having two holes, and the ropes going through each of them. I try to pull the left rope with my left hand... And it's heavy... Then I try to pull the right rope with my right ...
8
votes
2answers
575 views

How many times does the earth rotate per year?

Assuming there are exactly $365$ days per year. How many rotations about its axis does the earth make in one year?
38
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8answers
5k views

Who is our nearest planetary neighbor, on average?

Assume that the planets have circular orbits centered on the sun. Assume that the radius of the orbits is 0.39, 0.723, 1, and 1.524 for Mercury, Venus, Earth, and Mars. Assume also that there are no ...
4
votes
1answer
450 views

Is it Basic Physics?

Which number is next in the sequence? 1, 2, 3, 4, 5, 6, 7, 9, 10 ,11 ,12 ,13 ,14 ,15 ... Describe why and how your answer applies to the given problem.
1
vote
0answers
197 views

Is it possible to determine the original direction of water flow? [closed]

Take two beakers of water and use a spoon to stir water clockwise in one beaker and counterclockwise in the other beaker. Observe the beakers after a sufficiently long time when the water flow has ...
12
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2answers
321 views

Pucks in the arena

Two identical pucks of radius 10 cm are placed in a round arena of radius 1 m. They are positioned 50 cm away from the center of the arena on opposing sides. Assuming no energy losses during sliding ...
9
votes
4answers
521 views

Breaking Balance (Part C)

For a starting number of otherwise identical coins there are among them TWO IDENTICAL counterfeit coins which are either heavier or lighter than the rest. Using a three-pan balance (described in ...
2
votes
1answer
72 views

Breaking Balance (Part B)

If we assume the classic balance puzzle (Twelve balls and a scale) is phrased like this: You have 12 coins that are identical except for one counterfeit that is heavier or lighter. Can you use a ...
7
votes
5answers
353 views

Breaking Balance (Part A)

If we assume the classic balance puzzle (Twelve balls and a scale) is phrased like this: You have 12 coins that are identical except for one counterfeit that is heavier or lighter. Can you use a ...
9
votes
1answer
359 views

The Lazy Laser Physicist: Part 2

The Lazy Laser Physicist is quite shocked about what happened to his setup over night: Almost all of his mirrors were taken away, but some other things have been put on his table. Besides these there ...
15
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7answers
3k views

The Lazy Laser Physicist

You have a setup like in the image above. But it seems like detector A does some weird things. You should better check it with detector B. What is the minimum number of mirrors you have to move (...
10
votes
4answers
2k views

Where does the emperor sit and why the earplugs?

The Emperor is annoyed that the crowd routinely chant out of step at the Empire's largest circular amphitheatre. For example, they are supposed to shout phrases in unison such as "Hail to the Emperor, ...
14
votes
4answers
604 views

Balancing Balls

I have a disk with 6 equally spaced dents around the edge. The disk balances on the center point. I want to place marbles around the edge so that it stays balanced. There are four ways that this can ...
8
votes
7answers
1k views

Perpetual Motion Machine [closed]

An engineer tests a new generator by attaching it to a motor-powered cart. The generator operates such that the cart's batteries charge when the cart's wheels turn. Assume the following true ...
20
votes
7answers
2k views

Making a physicist

Materials: CV step-up transformer with coil ratio 1:5 Method: Apply the CV to the primary coil and spin it. Result: A physicist is output. Who? Hint 1: Hint 2:
5
votes
1answer
170 views

An Incorrect Summary of a Twenty-Two Day Tour

After a long but rewarding life in an office cubicle, Sally the office worker became Sally the retiree. Feeling unfulfilled, and with ancestors who had served admirably in the Navy, Sally the retiree ...
0
votes
1answer
251 views

Fuzzy's Fizzy Dilemma [closed]

Fuzzy the Fuzzball's friends was going to the Fuzzball Festival, and of course he went along. While there, he saw the most curious display. The booth was displaying brand new types of Fuzz. There was ...
11
votes
6answers
3k views

In which direction does the water flow?

There is a hard metallic pipe in your dark wine chamber. You hear the water flowing slowly in the pipe but you cannot understand in which direction that water flows since it is a closed system. ...
24
votes
15answers
12k views

Separate the milk!

You have a jug of milk and a jug of water. You must empty both jugs into a nine gallon barrel. You must be able to: Differentiate between the milk and the water Separate the milk from the water You ...
3
votes
2answers
261 views

Packing (cooking equipment) for Mars

Heading to Mars tomorrow, and I want to make sure I can still make my famous bean soup. Ordinarily I just cook it in a pot, but I remembered that beans are hard to cook at high altitudes, and Mars is ...
12
votes
5answers
801 views

More than equilibrium

Assume you have 2 identical metal cubes, the only difference being their temperatures $T_1 = 0 \, \text{°C}$, $T_2 = 100 \, \text{°C}$: The task is now to transfer as much heat as possible to the ...
-1
votes
2answers
265 views

Untwisting a long rope

Have you noticed that if you take your mouse and hang it from the end it will start to twist until it becomes untwisted? My puzzle is this: If you have a really long rope and not enough vertical ...
13
votes
10answers
2k views

Frequentists be damned! Design an evil coin to prove a point [closed]

The frequentists' definition of a "fair coin" is a coin that, tossed a million times, converges toward an equal number of heads and tails. But what is meant by converges? We might imagine a plot of ...
20
votes
4answers
2k views

Martin Gardner's “The Twiddled Bolts”

This is a puzzle of Martin Gardner, taken verbatim from My Best Mathematical and Logic Puzzles: Two identical bolts are placed together so their grooves intermesh. If you move the bolts around each ...
9
votes
2answers
452 views

A big logical mess

I found a drawing under a stack of books in my house. It looked like a logical circuit diagram, so I decided to make it. I assumed that I was allowed to put anything in the boxes with the question ...
3
votes
1answer
241 views

Figure out the ? in the figure below

Here is the link to the puzzle
-3
votes
1answer
218 views

Everyone is attracted to me! [closed]

Everyone in the world is attracted to me even though I'm the most abhorrent and repulsive creature to roam the earth. Though I am human, exploit no human weakness, and there are much more suitable ...