moment of inertia is a resistance force we know when we get

moment of inertia is a resistance force, we know when we get result from I-mr^2 with units Kgm^2 so what does it mean realy? suppose i calculated moment of inertia of a cube object from X axis is 215 kgm^2 so what does it mean of answer. is it giving the force required to give one complete rotation about X axis. is kgm^2 will be consider as kg force only, m^2 is for nothing? i m confused on this topic . please clear me anyone?

Solution

Moment of Inertia is simply the resistance to torque/moment of applied to a body. As you know from newtons law of motion F = m * a   where m is the resistance or inertia to acceleration . A higher value of m means a lower value of acceleration same is the analogy for moment of inertia.

Torque and angular acceleration are related as T = I * alpha where I is the moment of inertia , think of it like the inertia or resitance for the body to rotate on the application of the torque/moment same as the case with mass m.

Higher value of I means that the body will rotate much more slowly where a torque is applied to it. Moment of inertia is defined as mass * distance from axis^2 which implies that a higher the mass of the body higher will be its moment of inertia , greater be the distance from the axis higher will be the moment of inertia.