A tag for questions about the mechanical interactions of rotating objects, including torque and angular momentum.
0
votes
0answers
527 views
Rolling on an inclined plane [closed]
Let us consider a sphere. let it be released from rest from the topmost point of an inclined plane. Now let it come to a rolling motion, after a time x seconds. We can say that at time t= x seconds ...
2
votes
1answer
391 views
Lean angle of a turning bicycle
I'm asked to derive a relationship for the leaning angle of a bicycle with the following specs:
Center of gravity for bike and rider is a distance $L$ above the ground when vertical, and the total ...
6
votes
1answer
305 views
Spin-up time for fluid in an open cylinder with no endwalls?
I'm interested in how quickly (if at all) the fluid in an open cylinder would reach solid-body rotation if the cylinder is suspended vertically in an unbounded fluid.
I've found plenty of work that ...
11
votes
5answers
589 views
Why does the weighing balance restore when tilted and released
I'm talking about a Weighing Balance shown in the figure:
Press & Hold on onside of the horizontal beam and then release it. It makes some oscillations and comes back to equilibrium like shown ...
5
votes
3answers
399 views
confused about ball rolling and rotational energy
I was solving a practice test problem and it was just a conservation of energy problem
where a spherical ball is falls from a height h to the ground such that
$$mgh = \frac{1}{2}mv^2 + ...
2
votes
1answer
222 views
How to know the time a disc takes to stop from rotating and the numbers of revolutions
Assuming I rotate a disk, I want to know how long it takes to completely stop, and the number of revolutions it made since I removed my fingers off the disk.
Lets say a DVD I rotate with my fingers. ...
1
vote
0answers
160 views
Any interesting physics theroies/equations to be used in a video game? [closed]
I am designing a little game based on Newtons Graviational Law.
Are there any theories that I can use to create games?
thanks
3
votes
4answers
300 views
N particles, will there be any rotation after a period of time or everything will collapse
This is in context of classical Newtonian physics.
Consider a system of n different point mass particles. Initially all are spread around on one plane. No particle possess any velocity to begin with. ...
1
vote
1answer
133 views
Is it theoretically possible for the orientation angle of a projectile to remain exactly equal to the orientation of velocity?
This question is sparked by my answer to this question: Is this simulation following real physics?
After examining the math, I don't see how it is theoretically possible for the situation simulated ...
1
vote
1answer
217 views
Is this simulation following real physics?
I am trying to simulate a game in Box2D(Physics engine). The game that I am trying to simulate is very simple and can be found here: http://www.makaimedia.com/#/speartoss
What I want to know is that, ...
3
votes
4answers
791 views
Outcomes of earth slowing down spinning on its own axis
What are the possible outcomes if earth slows down spinning on its own
axis?
To be specific:
Can the decrease in the internal centrifugal (or centripetal) force due to slowing down earth's spin:
...
3
votes
2answers
256 views
Astronaut on a rotating asteroid
This might sound like the silliest question ever, but can someone shed some light on what is actually happening in the following situation:
There is an asteroid in outer space what is rotating with ...
0
votes
2answers
1k views
What are the ideal centers of mass and rotation for a steadicam?
For those who don't know what a steadicam is, I'll explain it in two points to give a basic idea. If you know what a steadicam is, skip to point 3.
1) A steadicam is a stabilizing mount for a motion ...
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votes
5answers
256 views
Does the rotational speed of a planet consistently become faster and faster given that there are no conflicting events? [closed]
Does the rotational speed of a planet consistently become faster and faster given that there are no conflicting events?
7
votes
2answers
2k views
Why does Venus rotate the opposite direction as other planets?
Given: Law of Conservation of Angular Momentum.
Reverse spinning with dense atmosphere (92 times > Earth & CO2 dominant sulphur based).
Surface same degree of aging all over.
Theoretical large ...
1
vote
1answer
200 views
Top spun up with string under tension problem [duplicate]
Possible Duplicate:
Homework about spinning top
I have a top with an unknown mass. It has a moment of inertia of 4.00 * 10^-7 kgm^2
a string is wrapped around the top and pulls it so that ...
2
votes
3answers
470 views
How long for a frictionless top to fall over?
We've previously discussed why it is that spinning tops do not fall over, see: Why don't spinning tops fall over?
However, as the highest rated answer notes, the angular momentum of the spinning top ...
7
votes
6answers
952 views
What determines which frames are inertial frames?
I understand that you can (in principle) measure whether "free particles" (no forces) experience accelerations in order to tell whether a frame is inertial. But fundamentally, what determines which ...
4
votes
4answers
3k views
Why does a ballerina speed up when she pulls in her arms?
My friend thinks it's because she has less air resistance but I'm not sure.
1
vote
1answer
598 views
Relation of angular speed of a rigid body to Euler's Angles
My Question was like this and i have realised few things and still have some doubts
I have a book in which a paragraph goes like this
Now, $\dot\phi$, $\dot \theta$,
$\dot\psi$ are respectively ...
3
votes
2answers
560 views
Question about moment of inertia and velocity
First off, I swear this is not homework. I'm doing some practice problems because I got an exam coming up. I'm stuck on this one:
I figured I would use energy conservation for this problem. So since ...
