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Physics · SYSTEMS OF PARTICLES AND ROTATIONAL MOTION
हिन्दीConsider the following statements regarding rotational motion of a rigid body about a fixed axis: (A) The angular velocity vector \( \boldsymbol{\omega} \) lies along the fixed axis of rotation. (B) The linear velocity \( \mathbf{v} \) of any particle is given by \( \mathbf{v} = \mathbf{r} \times \boldsymbol{\omega} \). (C) For a fixed axis, the angular acceleration \( \boldsymbol{\alpha} \) also lies along the axis of rotation. (D) A force whose line of action intersects the axis of rotation produces maximum torque. Which of the above statements are correct?
Correct answer · Option 2
(A) and (C) only
Explanation
For rotation about a fixed axis, \( \boldsymbol{\omega} \) and \( \boldsymbol{\alpha} \) lie along the axis, making (A) and (C) correct. Statement (B) is incorrect because \( \mathbf{v} = \boldsymbol{\omega} \times \mathbf{r} \), and (D) is incorrect because torque is zero when the line of action intersects the axis.
