7.
设\(Ox\)、\(Oy\)是平面内相交成\(60^{\circ}\)角的两条数轴,\( \overrightarrow{e_{1}}\)、\( \overrightarrow{e_{2}}\)分别是与\(x\)轴、\(y\)轴正方向同向的单位向量,若\( \overrightarrow{OP}=x \overrightarrow{e_{1}}+y \overrightarrow{e_{2}}\),则把有序数对\((x,y)\)叫做向量\( \overrightarrow{OP}\)在坐标系\(xOy\)中的坐标,假设\( \overrightarrow{OP_{1}}=(2,3), \overrightarrow{OP_{2}}=(3,2)\),则\(| \overrightarrow{P_{1}P_{2}}|=\) ______ .