Revision
of the use of the** Perpendicular axes theorem**

The
perpendicular axes theorem states:

** I_{Z
}**is
the moment of inertia of the body about the Z axis

** I_{X
}**is
the moment of inertia of the body about the X axis

** I_{Y
}**is
the moment of inertia of the body about the Y axis

**A
worked example**

Find
the moment of inertia of a uniform square lamina, of side 2l and mass M,
about an axis through it’s centre of gravity perpendicular to it’s plane.

wsheet2.doc contains further examples for practice( mass) ( side divided)_{Y}=^{2}= ( M)(l)^{2}

( mass) ( side divided)I_{X}=^{2}= ( M)(l)^{2}

I_{o}= I_{X}+ I_{Y}

= ( M)(l)I_{o}^{2}+ ( M)(l)^{2}

= ( M)(l)I_{o }^{2}