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The moment of inertia of a particle of mass m kept at point (a, b) on the x-y plane about the x-axis is

The moment of inertia of a particle of mass m kept at point (a, b) on the x-y plane about the x-axis is Correct Answer mb<sup>2</sup>

CONCEPT:

Moment of inertia:

  • Moment of inertia of a rigid body about a fixed axis is defined as the sum of the product of the masses of the particles constituting the body and the square of their respective distances from the axis of the rotation.
  • The moment of inertia of a particle  is


⇒ I = mr2

Where r = the perpendicular distance of the particle from the rotational axis.

  • Moment of inertia of a body made up of a number of particles (discrete distribution)


⇒ I = m1r12 + m2r22 + m3r32 + m4r42 + -------

EXPLANATION:

Given: mass of the particle = m, distance from x-axis = b.

  • The moment of inertia for the particle of mass m from an axis at a distance b is,


⇒ I = mb2

  • Therefore option 3 is correct.

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