Is My Approach to Solving the Inertia Tensor of a Rotating Cone Correct?

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SUMMARY

The discussion centers on calculating the inertia tensor and angular momentum for a uniform right circular cone rolling without slipping, as described in Goldstein's Classical Mechanics. The user successfully derived the inertia tensor for the cone positioned with its apex at the origin and aligned the axes according to the cone's surface. The angular velocity vector was expressed in terms of its components, leading to the formulation of angular momentum and kinetic energy equations. The user seeks validation of their approach and calculations, indicating a thorough understanding of the problem.

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  • Basic principles of rolling motion and non-slip conditions
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Saxonphone
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Homework Statement


From Goldstein's Classical Mechanics (Chapter 5 - Exercice 17 - Third Edition)
A uniform right circular cone of height h, half angle A, and density B rolls on its side without slipping on a uniform horizontal plane in such a manner that it returns to its original position in a time t. Find expressions for the kinetic energy and the components of the angular momentum of the cone.

The Attempt at a Solution



Well, first of all, I found the inertia tensor for a cone with the z axis along the axis of symmetry of the cone and the origin at his apex, then I made it "rotate" (90-A) degrees to put the x-axis in the line of the cone's surface that is always in contact with the plane (a drawing would be good I know, but...)

The tensor is diagonal and what i found was
a.jpg


As the angular velocity w( vector) always lies in that line, so one can say w (vector) = w(cosA k - sinA i) where w is the modulus of the vector and i and k the unit vectors of x and z.
w can be found with the data provided and is given by
b.jpg


Knowing all this, all I have to do is put what I got in L (vector)= I (tensor) w (vector) and T=1/2 I w^2.

The book got no anwers, so, anything wrong with what i did?
 
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I realize this is an old thread, but I'm working on this problem and am in a similar place as Saxonphone was. Does this look correct, so far?
 

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