Linked Questions

-1
votes
1answer
99 views

Why can't a pyramid stay balanced on a vertex? [duplicate]

A pyramid, such as a tetrahedron/3-simplex, or any other isohedron, falls from some height and lands on a vertex. It will eventually end up with a face to the ground. Why can't it stay balanced on a ...
27
votes
5answers
5k views

How would I move if I grew by a factor of 3 in each physical dimension?

Suppose, for the sake of this thought experiment, I am structurally identical to an average human, with the only difference being that my body is scaled in all directions by factor of 3. This would ...
4
votes
6answers
2k views

What is the uncertainty principle?

I looked on Wikpedia for information on the uncertainty principle, but after reading it I still had no idea. I know it has something to do with how many things you can hold at some spot for some ...
10
votes
4answers
6k views

How long would it take for an upright rigid body to fall to the ground?

Let's suppose there is a straight rigid bar with height $h$ and center of mass at the middle of height $h/2$. Now if the bar is vertically upright from ground, how long will it take to fall on the ...
9
votes
5answers
3k views

A conical pendulum. A textbook claims one can start the circular motion in an unintuitive way

A textbook claims that if you hang a mass from a string that's attached to a rod (so that the string is parallel with the vertical axis) and you spin the rod fast enough, you can put the mass into ...
7
votes
1answer
2k views

Is it possible to remove the last block from a the lowest layer of a Jenga tower?

A while back, my brother and I had a discussion about the possibility of removing the last block from the lowest layer of a Jenga tower with the layer immediately above it having only one block in it ...
2
votes
3answers
671 views

Is a dice roll deterministic?

This should be understood as distinct from the question of is it possible to predict the outcome of a roll, which seems to be an issue related to intractability and observation? What I'm really ...
2
votes
5answers
780 views

Which way will the pencil fall?

Let's say you had a perfect pencil, with a point which was just that one point (see this question). The pencil's mass was perfectly distributed, and there are no flaws in the craftsmanship. Let's say ...
2
votes
2answers
584 views

How fast can you spin a proton or electron without breaking it?

If you spin a single nucleus containing multiple nucleons fast enough it will fly apart. Is there a speed limit to a spinning proton or electron assuming it's held at a fixed location with a strong ...
-2
votes
2answers
470 views

Uncertainty principle on a simple pendulum

During simple pendulum motion at different points it has specific energy.That is how we can precisely predict its velocity as well as its definite position. It seems to violate Heisenberg's ...
0
votes
1answer
430 views

Why is it effectively impossible to balance this rectangle block on a triangle block? (See photo)

I've always wondered why it's basically impossible to balance a rectangle block on top of a triangle one like this. This is my nine-year-old giving it a try. I have never in my life gotten it to ...
1
vote
1answer
428 views

Movement and Rotation of a Inverted-Pendulum-like Object with External Forces

I'm struggling to model the movement of a complex object based on an external force. Let's start with a simple example of what I'm looking for. We have a block $b$ of mass $M_b$, moving friction-...
1
vote
1answer
285 views

Quantum properties of objects with zero velocity

What would the Heisenberg uncertainty principle and De Broglie wavelength be for a baseball that is not moving (i.e has zero velocity)? Also, since macroscopic objects like baseballs have extremely ...
1
vote
1answer
84 views

Mass and Pendulum falling from Vertical [closed]

I need a little help completing a mechanics problem. If you have a pendulum put vertically up with a rigid rod and ball on top of the rod and you give the ball some initial velocity $v_x$ how would I ...
0
votes
2answers
78 views

Is it possible to let a flag ``stand frozen in time``?

It´s clear that a moving flag is a chaotic system. But is it nontheless possible, under certain conditions and a uniform wind velocity, to make the flag look frozen in time, i.e., flat without ...

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