what is moment of inertia????The "second moment of area" is more commonly known as the "moment of inertia" and is a resistance to turning about an axis, just as inertia is resistance to movement.

The moment of inertia for a small particle is given by the mass of the particle multiplied by the square of the distance of the particle from the axis.

The moment of inertia for a large body is given by summing the moments of inertia for all particles of the body

 

since the mass m1 and m2 are at a smaller distance from the axis ...the guy feels easy to rotate

well in the second diagram mass m1 and m2 are at a farther distance and so it requires more force to rotate and is difficult to rotate....

oh now i got the idea ..moment of inertia depends on diatance and mass

formula:MR ^2