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Question
A uniform square plate has a small piece Q of an irregular shape removed and glued to the centre of the plate leaving a hole behind (Figure). The moment of inertia about the z-axis is then ______.
Options
increased
decreased
the same
changed in unpredicted manner
Solution
A uniform square plate has a small piece Q of an irregular shape removed and glued to the centre of the plate leaving a hole behind (Figure). The moment of inertia about the z-axis is then decreased.
Explanation:
In the given diagrams, when the small piece Q is removed and glued to the centre of the plate, the mass comes closer to the z-axis, hence, the moment of inertia decreases.
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