Phoenix Business Daily

What are the units of moment of inertia using grams and centimeters?

Also, how do you find the moment of inertia of an object about the line x = c? I have to find it about the line x = -3/4. I only know how to find the moment of inertia about the x, y, or z axis.

Public Comments

1. Moment of inertia has dimension mass times length squared. So using grams and centimeters moment of inertia has the unit g·cm² For 2nd problem use parallel axis theorem. I states that if you change axis rotation to a parallel axis at distance R moment of inertia changes from J₀ to: J = J₀ + M·R² where M is the mass of the rotating object. Let Jx be the moment of inertia about x-axis. Then Moment of inertia about line x=-3/4 is J = Jx + M·(-3/4)² = Jx + M·9/16 Note: add the corresponding unit for length to -3/4 to get correct result.