Does the Moment of Inertia Change When a Gyroscope is Lifted?

AI Thread Summary
The discussion centers on an experiment measuring the precession and nutation of a gyroscope, where the moment of inertia was calculated using a specific formula. Initial measurements taken with the gyroscope shaft horizontal aligned well with theoretical predictions. However, when the angle of inclination was changed, the results deviated from the expected outcomes, raising questions about the moment of inertia. The participant speculates that lifting the disc may cause the moment of inertia about the x-axis to change due to the shifting positions of mass relative to the pivot. This leads to the inquiry of whether the moment of inertia decreases when the disc is lifted.
Daniiel
Messages
119
Reaction score
0
Hey

I just finished an experiment in my physics lab where we examined the precession and nutation of a gyroscope.

The gyroscope was built with a shaft which had a pivot in the middle, on one end of the shaft the large spinning disc was placed and on the left side of the shaft counterweights were placed.

Torque was applied on the side of the large spinning disc, firstly the shaft was kept horizontal and several measurements were made (the angular precession frequency and the angular frequency of the spinning disc) then a relationship was developed and compared to a formula we were provided. This formula was wpr = T/(Ix wx)
Where T is torque r x F, Wpr the precession frequency, Wx the spin frequency and Ix the moment of inertia about the x-axis which was 0.5MR2 where M is the mass of the disc, R is it's radius.

Our results fit well this the equation provided and everything seemed correct.

We then examined the effect of changing the angle of inclination, so took the measurements again with the disc raised at various angles. The results obtained were not consistent with the forumla provided.

My question is, does the moment of inertia about the x-axis change when the disc is lifted, and if so does it decrease?

I would think it does change since at the horizontal everything is at its furthest apart positions, then when the disc is lifted above the horizontal everything moves closer towards the axis of the pivot, kind of hard to explain that sorry.

Here's a terribly drawn picture of the apparatus:
http://img198.imageshack.us/img198/4884/gyroscope.jpg


But yea, thanks in advanced,

Daniel
 
Last edited by a moderator:
Physics news on Phys.org
I'm sure you took into account that rxF is not a constant?
 
Yea we did,

Do you think its correct to think that Ix changes?
 
Thread 'Collision of a bullet on a rod-string system: query'
In this question, I have a question. I am NOT trying to solve it, but it is just a conceptual question. Consider the point on the rod, which connects the string and the rod. My question: just before and after the collision, is ANGULAR momentum CONSERVED about this point? Lets call the point which connects the string and rod as P. Why am I asking this? : it is clear from the scenario that the point of concern, which connects the string and the rod, moves in a circular path due to the string...
Thread 'A cylinder connected to a hanged mass'
Let's declare that for the cylinder, mass = M = 10 kg Radius = R = 4 m For the wall and the floor, Friction coeff = ##\mu## = 0.5 For the hanging mass, mass = m = 11 kg First, we divide the force according to their respective plane (x and y thing, correct me if I'm wrong) and according to which, cylinder or the hanging mass, they're working on. Force on the hanging mass $$mg - T = ma$$ Force(Cylinder) on y $$N_f + f_w - Mg = 0$$ Force(Cylinder) on x $$T + f_f - N_w = Ma$$ There's also...
Back
Top