(2) Firstly, calculate the area S of quadrilateral OABC: AB =14, OA=7, OC= 18, S = (AB+OC) * OA/2 = (14+7) *18/2.

Then find the areas of the two triangles ABQ and BCP: AQ=OA-OQ=7- 1*t=7-t, CP=2*t, S △ ABQ =1/2 * AB * AQ =1*.

Finally, find the area of the quadrilateral bqop = s-s △ abq-s △ bcp =189-(49-7t)-7t =140.

S 1=S△ABQ=49-7t, S2=S△BCP=7t, s 1 < S2, that is, 49-7t.

When s 1 < S2, find the range of t: 7/2.