# Thread: Volume, center of a mass and moment of inertia of a reqular square pyramid

1. ## Volume, center of a mass and moment of inertia of a reqular square pyramid

Hi,

In this problem I have a regular square pyramid (base length a , height b) and it's spun about its axis symmetry of z.

How do I find it's Volume?

And center of mass?

How about the moment of intertia of the pyramid?

Ps. Now in right forum I think

Thank you for your help as I've been stuck with this for while.

2. If its spun (like a top) along the z-axis, then it just makes a cone with similar height, but with circular base of radius [tex] \frac{a\sqrt{2}}{2}[tex]; see if you can derive that on your own.

Do you know how to find the volume of a solid in 3-dimension? If not I would review that, as the other two question follow from it.

3. Originally Posted by ANDS!
If its spun (like a top) along the z-axis, then it just makes a cone with similar height, but with circular base of radius [tex] \frac{a\sqrt{2}}{2}[tex]; see if you can derive that on your own.

Do you know how to find the volume of a solid in 3-dimension? If not I would review that, as the other two question follow from it.
Thanks. I'm not sure if I know how to find the volume. I know that need to divide it to sub-bodies.