There isn't really any such thing as regular yoga. I do know that in the US, many people associate yoga with hatha yoga, which usually means that the focus is on the building blocks of poses and on stretching-type poses.
Inertia is resistance to change. You hate looking at people's feet and yet you stay in your job as a shoe salesman year after year.
Inertial mass is a measure of an object's inertia: its resistance to changing its state of motion when a force is applied. An object with small inertial mass changes its motion more readily, and an object with large inertial mass does so less readily.