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0 votes
2 answers
115 views

When to apply $I_c \underline{\omega} = \underline{M_c}$?

I was solving an exercise the other day, about a rolling cylinder on an inclined plane. Initially the cylinder slides, but then it begins to roll and the problem wanted to know the velocity of the ...
Matteo Menghini's user avatar
2 votes
1 answer
1k views

Angular velocity across different reference frames

In classical mechanics: Logically, it appears to me that if I draw a mark on a ball and let it roll, the amount of time that will pass before the mark reaches the same position (in terms of angles: ...
Shay's user avatar
  • 183
2 votes
1 answer
330 views

Understanding Euler's Rotation equation for rigid bodies (Frames Of Reference)

$$ \tau_b=I_n\dot\omega_b+\omega_b\times I_b\omega_b $$ Now in the above is Euler's famous rigid body rotation equation, in the body frame of reference ..... this does not make sense to me. How can a ...
Mubarak Salley's user avatar
3 votes
1 answer
1k views

Why is total kinetic energy always equal to the sum of rotational and translational kinetic energies?

My derivation is as follows. The total KE, $T_r$ for a rigid object purely rotating about an axis with angular velocity $\bf{ω}$ and with the $i$th particle rotating with velocity $ \textbf{v}_{(rot)...
user avatar
0 votes
1 answer
332 views

Lagrangian of a Heavy Symmetrical Top - Inertial or Non-inertial Frame?

I'm having some confusion with the analysis of a symmetrical top (specifically, a heavy top, but this is not very important for the question). Following Landau and Lifshitz's Mechanics, on page 110 ...
confused's user avatar
3 votes
1 answer
137 views

These components of the angular velocity are given in what reference frame?

When we have a rigid body, the rigidity constraint allows us to write the trajectory $\mathbf{r}_i$ of the $i$-th particle as $$\mathbf{r}_i(t) = R(t)\mathbf{b}_i + \mathbf{w}(t),$$ where we are ...
Gold's user avatar
  • 36.4k
3 votes
0 answers
130 views

Gauge formalism in rigid body mechanics

When doing calculations in rigid body mechanics, it is necessary to choose an origin to calculate torques and angular momenta. However, the underlying dynamics does not depend upon the choice of that ...
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