in classical mechanics, the moment of inertia (also known as mass moment of inertia) is usually represented by i, and the si unit is kg * m2. it can be said to be the inertia of an object for rotational motion. for a particle, i = mr^2, where m is its mass and r is the perpendicular distance between the particle and the axis of rotation. the role of rotational inertia in rotational dynamics is equivalent to the mass in linear dynamics, describing the relationship between several quantities such as angular momentum, angular velocity, torque and angular acceleration.

formula usage:

moment of inertia = m * d²

m = mass

d = vertical distance between the particle and the axis of rotation