Calculate Torque/Power for Rotating Tube & Rectangular Parallelepiped

[Rem Grwthy]

I want to calculate the torque of the construction or the needed Power (Watt) to rotate it. The construction is a tube and on top of tube is stuck a rectangular parallelepiped:

Tube:

inner diameter=d=92mm, outter diameter=D=102mm, lenght=L=3000mm, mass=12.34kg

Rectangular parallelepiped:

x=3000mm, y=5000mm, z= 50mm, mass=250kg

http://www.ffevents.gr/nikos/sxediopaint.jpg

...Please assume missing data if needed.....

 

[Cyrus]

You need to show an attempt of solving this problem on your own. You question is also wrong in the sense that the power to rotate something depends on the angular velocity, which is not given in your problem statement.

 

[Rem Grwthy]

ok forget about this... But can you calculate the moment of inertia for this construction??

 

[Cyrus]

You could do it as the summation of two composite bodies. Again, your question is posed wrong because the mass moment of inertia is about a specified axis. You can find the MMOI of the two bodies you have drawn in any standard engineering statics or dynamics book.