Question

What are the types of moments of Inertia ?

Answer 1

Hint:Moment of inertia is the property of a rigid body by virtue of which it opposes change in its rotational motion. in more simple terms, it can be described as a quantity that decides the amount of torque needed for a specific angular acceleration in a rotational axis. Moment of Inertia is also known as the angular mass or rotational inertia.

Complete answer:
Moment of Inertia can be divided into three types:
Mass moment of inertia:It is defined as the resistance of an object due to its own mass, when the object is rotating. It can be understood as it measures the ability of the object to resist any change in the rotational speed about a specific axis. The mass of the moment of inertia is represented by “I” in calculations.

Area moment of inertia:It is defined as the resistance of an object due to a bend in the body. It can be understood as a property that is used to predict deflection, bending and stress in beams under some load. It is also represented by “I” in calculations.

Polar moment of inertia:It is defined as the resistance of an object to the torsion(twist). It is considered when the object is prone to twist while applying the torque i.e., rotating force. The greater the magnitude of the polar moment of inertia, the greater the torsional resistance of the object. It is also represented by “I” in calculations.

Note:You need to implement one of these types of moment of inertia on the question, depending upon what situation is given to you. All these types are independent of each other, while some can be common to an object in a given condition. MOI (Moment of Inertia) is always taken with respect to a specific axis of rotation. MOI plays the same role in rotational motion as mass plays in translational motion.