Questions tagged [gyroscopes]
A spinning wheel or disc in which the axis of rotation is free to assume any orientation by itself. When rotating, the orientation of this axis is unaffected by tilting or rotation of the mounting, according to the conservation of angular momentum. These devices are used for measuring or maintaining orientation and angular velocity.
32
questions
16
votes
7
answers
28k
views
What determines the direction of precession of a gyroscope?
I understand how torque mathematically causes a change to the direction of angular momentum, thus precessing the gyroscope.
However, the direction, either clockwise or counterclockwise, of this ...
- 161
31
votes
7
answers
18k
views
Why don't spinning tops fall over?
One topic which was covered in university, but which I never understood, is how a spinning top "magically" resists the force of gravity. The conservation of energy explanations make sense, but I don't ...
- 2,694
13
votes
9
answers
23k
views
How do you explain spinning tops to a nine year old?
Why don't spinning tops fall over? (The young scientist version)
My nine year old son asked me this very question when playing with his "Battle Strikers" set. Having studied Physics myself, I am very ...
- 177
7
votes
1
answer
1k
views
Without using rotational mechanics, why does a gyroscope precess the direction it does?
When a top is spun, it will precess in some direction, either clockwise or counterclockwise. It's possible to find out which way using $\boldsymbol{\tau} = d\mathbf{L}/dt$ and $\boldsymbol{\tau} = \...
- 98.7k
5
votes
2
answers
2k
views
What gives energy for precessional motion of gyroscope?
Let us suppose we have an ideal friction-less gyroscope and it is suddenly given an angular momentum, and left as in the figure. It will start precessional motion.
Since there is no friction, the ...
- 3,010
3
votes
1
answer
513
views
The tennis racket theorem with degenerate eigenvalues $I_1, I_2 , I_3$: Are the rotations around the principal axes stable?
If a rigid body has a symmetry such that two of the principal moments of inertia are equals, i.e. $$I_1=I_2> I_3 \qquad{\rm or}\qquad I_1>I_2=I_3.$$
Are the rotations around the principal axes ...
- 452
2
votes
1
answer
386
views
Reasoning behind predicting a gyroscopes motion
Lets say we have a gyroscope that has a flywheel spinning with constant angular velocity. The gyroscope is held in place in a position where the massless metal rod connecting to the flywheel is ...
- 300
21
votes
5
answers
6k
views
Why does a spinning top get back upright when knocked?
I have observed that, a spinning top, when toppled by knocking it with finger, becomes almost upright again (with negligible precessional motion), instead of undergoing precession while being heavily ...
- 3,010
4
votes
2
answers
13k
views
What causes precession or nutation in a spinning object?
What causes precession in a spinning object?
What causes nutation in a spinning object?
What causes a top, gyroscope, and the earth to wobble?
Just because it's a simple question, I'm not expecting ...
- 321
4
votes
1
answer
2k
views
Gyroscope's motion explained by internal forces
I'm having a hard time trying to figure out the inner mechanisms behind a gyroscope's precession and nutation. To be very specific, I want to consider gyroscopes like this one:
(source: wordpress.com)...
- 604
3
votes
3
answers
630
views
Are gyroscopes the only way to maintain the orientation?
Gyroscope is quite popular, one can even find it in iphone etc. But, is such
Gyroscope the only way? are there any other ways to build machine that to measure or maintain the orientation?
- 405
1
vote
2
answers
3k
views
How attitude indicator (gyro horizon) adjusts to the Earth's curvature?
Image a plane is flying from North to South and is crossing equator. How gyro horizon would maintain correct pitch angle? (Or East-West?)
I assume that pitch angle is correct at takeoff, so the ...
- 13
1
vote
2
answers
2k
views
Describing a motion of gyroscope with gimbal
Can you tell be how to set the equations to describe the motion of this machine
in movie "Contact":
https://www.youtube.com/watch?v=TSaO9VGjLXc
This is gyroscope with gimbal, am I right?
- 19
0
votes
4
answers
926
views
Is it possible to understand the Gyroscope Effect Intuitively?
A stationary wheel, with its axis tied only at one end, falls down, but a rotating wheel, with its axis tied only at one end, doesn't fall down. The explanation given everywhere is by the ...
- 2,043
33
votes
3
answers
4k
views
How do we stabilise satellites so precisely?
Look at the Hubble Ultra Deep Field photo. The stars in it are on the order of 1 arcsecond across. To an order of magnitude, this is $10^{-6}$ radians in a $10\text m$ telescope which was held steady ...
- 4,798
9
votes
2
answers
1k
views
What's the deal with the gyroscope?
In this article ("The problem with physics", Tony Rothman, ABC science) the author says in the 5$^\textrm{th}$ paragraph:
For example, one needs only first-semester equations to describe reasonably ...
- 2,141
8
votes
1
answer
1k
views
Defy gravity torques with gyroscopes?
Context
On the following drawing, a platform is hung from the ceiling not exactly from its centre of gravity. Because of this it can't sustain an arbitrary orientation for long; I want to increase ...
- 745
4
votes
1
answer
1k
views
The moment of inertia of a spinning gyroscope assembly
Moment of Inertia (MOI) is typically used to describe a rigid body, so I don't know how well I can express my question in those terms. However, it seems like the best framework for getting at my issue....
- 165
4
votes
1
answer
3k
views
Minimum speed needed for a gyroscope to precess
I was reading about gyroscopes and their precession. Based on the text, the angular speed of precession is: $\omega_{precession}=\dfrac{\tau}{L}$ But intuitively, if the wheel of the gyroscope is ...
4
votes
1
answer
522
views
SLR camera gyroscopic stabilization - limited by rotation of the earth?
In this photography stackexchange answer it is stated that the limits of performance of gyroscopic stabilization of an Olympus handheld camera is related to the rotation of the earth. I'm further ...
- 6,638
4
votes
2
answers
2k
views
Gyroscopic Force/Torque of a Constrained Wheel
Description
I have a wheel spinning away from me in the vertical plane. The angular momentum is pointing to the left. The axis of rotation is horizontal, and it is supported on either side by a ...
- 53
4
votes
1
answer
14k
views
Gyroscope in an airplane following the curve of the Earth
This video from a high-profile skepticism channel perports to debunk a flat-Earth nut. But, Greg’s explaination of why the artificial horizon instrument on an aircraft works properly seems to me to be ...
- 5,167
3
votes
1
answer
555
views
Confusion about what happens when the rotating axis of a gyroscope is rotated
In A.P. French's Newtonian Mechanics, pages $684$ and $685$ , the author said the following about gyroscopes,
If a gyroscope, mounted in its gimbal rings, is set spinning about a horizontal axis, ...
- 1,202
3
votes
5
answers
15k
views
Direction of torque precession of a spinning wheel
Consider a spinning wheel, which is held up by one end of it's axis like this:
To explain why the change of angular momentum is directed as shown in the figure above, one usually says that there is ...
- 1,111
2
votes
2
answers
703
views
Gyroscope precession
I have a system diagrammed and explained in the image below.
Experimentally I believe the wheel will rotate around the pivot point where the cable is attached in a counter-clock motion if observed ...
- 1,209
1
vote
0
answers
923
views
How do bikes stay upright? [duplicate]
Possible Duplicate:
Why doesn't the bike fall if going with a high speed?
How does a bike stay upright? I know there are various theories involving castor effects, and gyroscopic motion but ...
- 530
1
vote
1
answer
887
views
If gyroscopes are used as resistance devices, where does energy put in go?
If two gyroscopes were to be started with parallel angular momentums, linked by a rotating tube (one perpendicular to the axle), then a second pair added that is the exact reverse such that it has ...
- 123
1
vote
1
answer
119
views
Derivation of precession rate of a wheel gyroscope [closed]
I searched on the web and all I could find is the precession rate of a spinning top. But what I want is the derivation of the precession rate of a wheel hanging from a rope, as shown below:
which is ...
- 410
1
vote
0
answers
1k
views
Direction change of gyroscopic precession with change in moment of inertia
In the classic bicycle wheel gyroscopic precession, using the right hand coordinate system of xyz and right hand rule of rotation,
Such as
X axis is in the longitudinal direction (spin axis)
z axis ...
- 11
0
votes
0
answers
69
views
Is there a naturally occurring siderostat (fixed orientation, absolutely nonrotating object as if locked to the distant galaxies or the universe)?
Often, a telescope is attached to an equatorial mount with a motor that counteracts the earth's rotation so that the telescope has no net rotation. It may be designed to counteract the known rotation ...
0
votes
1
answer
911
views
Which force acts as centripetal force on gyroscope?
I think I have understood gyroscope in terms of angular momentum and how the torque of gravitational force moves it the way it does.
Also I understand the direction in which it would move:
What ...
0
votes
1
answer
367
views
Purely mechanical description of how gravity causes a gyroscope to precess
I know the vector equation that relates torque to moment of inertia and angular momentum. What I want to know is what physical mechanisms actually occur to keep the gyroscope from falling. Where is ...
user31580