Question

Explain the concept of moment of inertia

Answer 1

The moment of inertia is the resistance to change in rotational motion analogous to the mass for linear motion. If you think about the definition of energy = 1/2mv^2, using w is angular velocity we want to define I so that 1/2 Iw^2 is also the energy. But v=rw so mv^2=mr^2w^2 so if we define a variable I=mr^2, then we have the desired result, the energy of an object rotating at a angular velocity w will be 1/2 Iw^2. You can do calculations with out using I but it is more tedious

Answer 2

Say you are driving down the road and you hit the break and you feel your body move forward towards the wheel. As we all know it is actualy a backwards force and your body is just trying to stay in the same position. Basicaly the moment of inertia corresponds to newtons law "A object at rest will stay at rest or a object in motion will stay in motion unless a outside force interfere`s" The moment of intertia is when the outside force interferes and the body in question wants to stay in its original place.