A uniform \( \operatorname{rod} A B \) hinged about a fixed point \( P \) is initially vertical....

A uniform \( \operatorname{rod} A B \) hinged about a fixed point \( P \) is initially vertical. A rod is released from vertical position. When rod is in horizontal position.
The acceleration of the centre of mass of the rod is
(1) \( -\frac{6 g}{7} \hat{i}-\frac{3 g}{7} \hat{j} \)
(2) \( -\frac{12 g}{7} \hat{i}-\frac{6 g}{7} \hat{j} \)
(3) \( -\frac{3 g}{7} \hat{i}-\frac{9 g}{7} \hat{j} \)
(4) \( -\frac{9 g}{7} \hat{i}-\frac{3 g}{7} \hat{j} \)