Cao = 30, o is in h,

Then OH= 1/2OA=2,

Analytical formula of linear AC: Y=√3/3X+4√3/3,

The analytical formula of the straight line MN passing through O parallel to AC is: Y=√3/3X,

The intersection of MN and parabola, solving the equation;

Y=√3/3X，

Y=√3/3(X^2+3X-4)

It is obtained that: x =- 1 √ 5, and CQ=OC=4√3/3, ∴ Q (0 0,8 √ 3/3) is on the positive semi-axis of the Y axis.

Analytical formula of straight line parallel to AC on Q: Y=√3/3X+8√3/3,

Simultaneous equation:

Y=√3/3X+8√3/3，

Y=√3/3(X^2+3X-4)

X =- 1 √ 13

∴ p: the abscissa of-1√ 5 or-1 √ 13.