Parallel axis theorem ( at mass moment of inertia)


Parallel axis theorem ( Huygens –Steiner theorem) , can be used to determine the mass moment of inertia or the second moment of area of a rigid body about any axis, given the body’s moment of inertia about a parallel axis through the object’s centre of mass and the perpendicular distance between the axes. The parallel axis theorem states that if a body is made to rotate instead about a new axis which is parallel to the first axis and displaced from it by a distance “r”, then the moment of inertia with respect to the new axis is related to the moment of inertia that the body has if axis of rotation is passing through the body’s center of mass.

Related formulas


IMoment of inertia ( parallel axis) (kg*m2)
IcmMoment of inertia (axis at the centre of mass) (kg*m2)
mMass of the body (kg)
rPerpendicular distance between the two axes (m)