- #1
lilphy
- 28
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Homework Statement
hello,
i want to calculate the inertia tensor of the combination of a point mass and a sphere in the object's frame, the center of mass is at the origin. The point mass remains at the surface of the phere
The sphere is uniform, radius r and mass M, and the point mass has mass aM.
My sphere is centered at the origin χ
Homework Equations
The Attempt at a Solution
The inertia tensor of a sphere of radius R and mass M is known
I did all the work of finding the distance to the center of mass of the system to the origin, the inertia tensor of the sphere about the center of mass of the system sphere-particle.
Now i have to find the tensor of inertia of the point mass about the centre of the sphere, I found this formula :
Iij=dm(δij r2-rirj)
So I got these values for Iij:
I11=I22=I33= aMR2
And all the other values are = to -aMR2
Is this correct ?
Thanks