79So we can say that the com of the rod will fall in a straight line.
Now considering a circle about O.
So the center of the rod will fall through the line of the standing rod.
The point will be below L/2.
Now tilting the rod to an angle of 90-θ.
So the point P will be at a distance of OP from O and same from the bottom of the rod.
Considering similar triangles--
OP=z.
z/zcos θ=(L/2)/√(L2/4-4z2sin2θ)
On solving this we get z=L/4.