The 11.5 kg slender rod pivoted about point O is pressed against a spring at point A, in which the spring (k = 375 kN/m) is compressed by 27 mm, as shown in Figure Q2(b). At this instance, the rod is...

The 11.5 kg slender rod pivoted about point O is pressed against a spring at point A, in which the spring (k = 375 kN/m) is compressed by 27 mm, as shown in Figure Q2(b). At this instance, the rod is at horizontal position and is stationary. If the rod is released from this position,

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   (i)  By using the principle of conservation of energy, explain with calculations on how changing the mass of the rod would influence the downward reaction of the pivot when the rod passes through a vertical position.