Initially, the plates of a parallel plate capacitor shown in figure are A and B containing charges $+2\mu C$ and $-2\mu C$ respectively. Negatively charged plate B is connected to a spring of spring constant $5000N/m$ at one end and the other end of the spring is connected to a rigid support. Now the plate A is fixed and the system is released from rest. The maximum elongation produced in the spring is $\frac{\alpha \times {10}^{-12}}{{\in }_0}m$. The area of the plates is $2c{m}^2$, the medium between the plates is air and electric permittivity of air is ${\in }_0$ (in SI). Then find the value of $\alpha$.