The tag has no wiki summary.

learn more… | top users | synonyms

1
vote
1answer
50 views

Does precession of a rigid body change instantaneously?

I read some explanations of precession; this side for example summarizes briefly almost all what I have understood so far. But one thing bothers me: Following all this formulas, the precession ...
1
vote
0answers
16 views

When will be a suspended (not at the center of the mass) symmetric rotating gyroscope in stable or instable position?

The original question is what is in the title. I'm not sure about the answer so here is my solution, please correct me If I am wrong: It is known for a gyroscope what is in a homogenous gravity field ...
24
votes
3answers
2k 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 ...
0
votes
2answers
41 views

Do comets spin? Why do satellites/space station not spin?

Do comets spin? Why don't satellites or space-station spin? If spin is fundamental thing, then it should be found in all (moving) objects.
0
votes
2answers
256 views

How, exactly, does a reaction wheel work?

Reaction wheels, mounted on spacecrafts and satellites, are used for precision attitude control. It is not clear to me how they can do this, though. My best guess is that when a motor accelerates a ...
0
votes
1answer
379 views

How to calculate speed and distance from gyro, orientation and acceleration data?

In iOS 8 SDK, there's an API that gives you a distance covered by user over a period of time. I wonder how is Apple calculating distance, as it seems to work without GPS help. And since I have the ...
0
votes
0answers
69 views

Calculations to Determine Force Required for Gyroscopic Stabalization

I am currently undertaking a project involving gyroscopes, the aim of which is to stabilize a large object. I have read that gyroscopes work because of conservation of angular momentum, and if you ...
0
votes
0answers
15 views

Spinning top don't fall and stationary one can't stay upright [duplicate]

Why a spinning top do not fall but a stationary one falls. What kind of law is governing it.
1
vote
0answers
29 views

Most general gyroscope motion [duplicate]

In Kleppner & Kolenkow's Introduction to Mechanics (Amazon link), the general gyroscope motion including nutation was derived using the approximation condition $\Omega T \ll 1$ where $\Omega$ is ...
1
vote
1answer
35 views

Gyroscope motion: Why is $\vec{\Omega}$ vertical?

Since I can't sketch here I am referring to: Feynmanlectures-Gyroscope Assume that you have got a gyroscope (as in Figure 20-3 in the link) that pivoted and can turn around any axis. Let $\vec{L}$ be ...
18
votes
6answers
9k views

Can a car steer on a frictionless surface?

Do the front tires of a car act like gyroscopes, such that a car could steer on a frictionless surface?
0
votes
0answers
40 views

Is it possible to reverse gravital direction of center of a mass by gyroscopic movements?

I am sorry that I don't know exact terms to define my question in physics. I watched a few videos that showed moving objects by its own like cubli (gyroscopic moving parts by means of mini motors and ...
0
votes
1answer
42 views

Counter-rotating flywheels for “flying saucers”

In 1974, while living in a farmhouse next to the Johns Hopkins Applied Physics Laboratory in Laurel, MD, I became obsessed [to the total consternation and perturbation of my wife, of that time, and my ...
1
vote
3answers
59 views

Why do we add the spin angular velocity and orbital anglar velocity when asked to calculate total angular velocity of Gyroscope?

Normally when we talk of angular velocity we mean how the angle of a vector changes with time with respect to an origin.Thus the oribital angular velocity of gyroscope makes sense to me.However I find ...
1
vote
0answers
33 views

Noise of a fiber optic gyro

I have not much experience with noise handling or calculations, furthermore in my researches couldn't find a similar problem, so here is my attempt: Having a fiber optic gyro that is rated with a ...
1
vote
0answers
80 views

Which force is necessary for providing centripetal force to a rotating gyroscope?

When a gyroscope is precessing around an axis due to a certain applied torque, if we look at the center of mass , it is going around in circular motion. So there must be some force which provides the ...
3
votes
3answers
96 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?
1
vote
1answer
294 views

How to use accelaration data of moving object to calculate distance?

I read couple of similar question on this forum and few blogs on web, though I am still confused,I am determined to calculate object displacement using accelerometer data. So, I tried using ...
0
votes
0answers
45 views

The Linear acceleration in Gyroscope

I am trying to understand theory behind the Gyroscope. I found this article that explains things in much detail. But I am unable to understand how that perpendicular acceleration components (a1, a2) ...
-1
votes
2answers
116 views

The charm of the gyroscope [closed]

I am fascinated by the gyroscope, like everyboy who was so lucky as to get such a toy as a kid. But probably also grown-ups are not immune to its charm. I am not asking for a theoretical explanation. ...
4
votes
1answer
114 views

What does a MEMS gyro measure during off-axis rotations?

I've been working with MEMS gyroscopes in hobbyist projects for years—but it's recently come to my attention that I don't have any principled understanding of what rotation rate measurements ...
0
votes
0answers
30 views

Calculating the force of a gyroscope attached to an armature

I stumbled across an illustration of a simple legged armature stabilized using a gyroscope, and I'm attempting to understand the math behind it. I've simplified the model to this diagram: Given ...
1
vote
0answers
151 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 ...
8
votes
1answer
658 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 ...
0
votes
1answer
357 views

Model the gyroscopic effect for 3axes stabilisation

Context I am trying to stabilise a platform on a guimbal using 3 axes gyroscopes. I have made tons of research (same problem for weeks even months now) without being able to properly model the 3 ...
7
votes
1answer
89 views

Why does the heaviest point on a spinning ball tend to become the topmost pole? [duplicate]

I have a mostly hollow, small clear plastic ball. Inside the ball is a weight stuck to the edge but the weight is smaller than the ball so the ball will always come to rest with the weight at the ...
3
votes
2answers
243 views

Why does pitch in a helicopter take effect 90 degrees later?

In a helicopter if you want to give it a forward pitch, you change the angle of the blades when it is in this position ---- So the two blades experience unequal lift and because o gyroscopic ...
1
vote
2answers
374 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?
0
votes
1answer
380 views

Torque and angular acceleration with bicycle wheel

This might be a simple problem for many of you. However, please help me understand it too. I have been looking trough a lot of materials online, and I still have the following questions, that would ...
2
votes
0answers
49 views

What is the longest distance over which echolocation is effective?

Some animals, most notably bats, use echolocation in order to navigate and detect the location and size of objects and prey. This usually takes place over short distances. What are the theoretical ...
9
votes
1answer
548 views

What makes a wrist-energized gyroscope rotate faster?

I'm considering a wrist-energized gyroscope, shown below (after my daughter let it fall and it broke open). That one was sold as Roller Ball, but variants are known as Powerball, DynaBee, Dynaball, ...
4
votes
1answer
197 views

Understanding gyroscopes

Considering the typical situation of a rotating bicycle wheel held by one end of its axle by a rope tied to the ceiling: gravity torque is the time derivative of the angular momentum, and in this case ...
1
vote
0answers
72 views

Bottom magnetic levitation

There are many decorative devices, that keep a small metal sphere levitating in air by attracting it to a top electromagnetic coil while monitoring their height by optical sensors. There is also the ...
0
votes
1answer
152 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 ...
0
votes
1answer
97 views

Why does precession only occur at high angular speeds?

I'm trying to understand precession for a gyroscope or top. I do understand why precession occurs using the vectors for the weight force and torque and angular momentum. But what I don't understand ...
-2
votes
1answer
61 views

Can we define angular momentum for the wheel under motion?

According to the definition of angular momentum: Angular momentum, moment of momentum, or rotational momentum is a vector quantity that represents the product of a body's rotational inertia and ...
1
vote
0answers
60 views

Movement of a gyroscope with non-fixed axis

Assume one has a gyroscope rotating around an axis with both ends leaning on a dedicated semiplane as shown on the picture below. There is no friction either between the rotor and the axis or between ...
5
votes
2answers
246 views

Will a wheel rolling down a hill ever fall over?

Say I have a detached bicycle wheel and I roll it down an infinite, flat, asphalt inclined plane, in air (ie there will be a terminal velocity). When, if ever, will the wheel fall over? I've been ...
0
votes
1answer
1k views

how to determine direction of gyroscopic couple on car?

How can I determine the direction of the force acting due to gyroscopic couple on a car's wheels when it is taking a turn to it's left side?
4
votes
2answers
472 views

Why do gyroscopes not maintain their stability as seen in this video

What exactly causes gyroscopes to oscillate as seen in this video. http://www.youtube.com/watch?v=gdAmEEAiJWo Even when my toy gyroscope spins on Earth, I get oscillations. Is this a result of ...
1
vote
1answer
323 views

Physics of the point of contact for a spinning top

I understand how spinning tops don't tip over, cf. e.g. this and this Phys.SE questions. What I'm more interested is in identifying the factors that determine the direction the spinning top moves to? ...
3
votes
2answers
3k 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 ...
1
vote
1answer
116 views

Gyroscope bombardment

Let's say I have a spinning steel ball that I have somehow managed to be completely free in all axes of movement. If I fire a BB at it with enough force on a north-south (to the ball) angle, what will ...
5
votes
4answers
7k 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 ...
3
votes
1answer
808 views

what happens when I roll a gyroscope along its axis of spin

Say: I have a gyroscope that is spinning in the xy plane along the z axis. I then roll its spinning axis by some angle theta Now I know the gyroscope will resist my attempting to change its axis ...
2
votes
0answers
440 views

propeller flying physics for the layman

I'm starting a (quad?)copter build, and i can find plenty of knowledge about stabilizing the craft and things related to gyroscopy. but there's absolutely zero information on things that help me ...
0
votes
1answer
393 views

Space Rocket Lift Efficiency and the Gyroscope?

I'm no physicist apart from basic 3d web animation, I'm just curious and please feel free to correct my misuse of terms or inadequate speculations. I've been reading a lot on gyroscopes and ...
2
votes
1answer
614 views

Double gyroscope: Can a spinning pencil tumble on only one axis?

Picture an object such as item 7 on this page .. http://en.wikipedia.org/wiki/List_of_moment_of_inertia_tensors Call that the x axis and z is in to the distance. See diagram below. We are in deep ...
2
votes
1answer
317 views

Will a precessing spinning wheel fall down if there is no friction at all?

If there where no friction at all, would a spinning wheel held up by one end of the axis spin precess forever without falling down? I just asked another question about the same problem: Direction ...
1
vote
3answers
4k 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 ...