the moments of inertia of frequently occurring shapes (such as a uniform rod, a uniform or a hollow cylinder, a uniform or a hollow sphere) are well known and readily available from any mechanics text, including your textbook. however, one must take into account that an object has not one but an infinite number of moments of inertia. one of the distinctions between the moment of inertia and mass (the latter being the measure of tranlsational inertia) is that the moment of inertia of a body depends on the axis of rotation. the moments of inertia that you can find in the textbooks are usually calculated with respect to an axis passing through the center of mass of the object. however, in many problems the axis of rotation does not pass through the center of mass. does that mean that one has to go through the lengthy process of finding the moment of inertia from scra