Moment of Inertia

Moment of inertia is related to the study of rotational movements of a body (usually, rigid). It is a part of physics and is very instrumental in studying and understanding applied physics topics. Moment of inertia can be defined as the friction or the forces that oppose the rotational movement of a body or an object and which is experienced by it during the rotation as it rotates around an axis. Related to the study of moment of inertia is the force of torque. So, to understand properly what moment of inertia is, all the other terms must be studied. 

Moment of Inertia

The moment of inertia is related to two major things- inertia and torque. Torque is a kind of force that makes an object rotate about an axis and is essentially the turning force that acts on an object or a body. Inertia is the universal tendency that is observed in almost every object in the universe where they exhibit a peculiar feature, first noticed and codified by Newton’s laws. 

Angular Momentum

While studying the topic of the moment of inertia, certain things have to be kept in mind:

• The axis involved in the rotation may or may not be fixed and may or may not be external
• Moment of inertia at any given point related to the axis is specified
• It is represented as (I).

The definition of the phenomena- a moment of inertia goes as follows- is essentially the result of multiplying the square distance (calculated from the point of the axis) and the individual mass of every possible particle contained within that object. Moment of inertia is very crucial to calculating the angular momentum (a characteristic of rotary inertia). The meaning of moment of inertia has been explained in the above passage and it simply means the resisting forces acting and impacting the rotation of a body that is moving or rotating. 

Inertia

To better understand rotary inertia (moment of inertia), inertia needs to be understood. To simply put, inertia is a type of resistance that is experienced on an object and that can change the velocity of the object. Inertia affects two things – direction and speed. Inertia has a lot of connection to gravity and its workings, force and motion as well as relativity. Rotary inertia is a quantity of inertia in physics that postulates that a body that is rigid and in rotation will continue to rotate throughout its duration with a constant rotational motion and there is no change recorded in the angular momentum. 

The formula of Moment of Inertia

Rotary inertia has the formula of I = L/w. Here, I stands for rotary inertia, L is the total angular momentum and w is angular velocity. When considering a pendulum, the formula changes to I = mr2. Here, m is pendulum mass r is the pivot point distance. 

Conclusion

Due to inertia, a body will remain in the state of inactivity or activity so long another external force does not cause any disruption or a change. The moment of inertia is related to two major things- inertia and torque. This means that a body will continue to move until something stops it or changes its action. Similarly, an object will not move and be fixed or rest until another force comes in to change that. So, while observing a moment of inertia, the concepts of inertia and torque are witnessed and they affect the object.