Three identical spheres of mass m, are placed at the vertices of an equilateral triangle of length a. When released, they interact only through…

Three identical spheres of mass m , are placed at the vertices of an equilateral triangle of length $\displaystyle a$. When released, they interact only through gravitational force and collide after a time $\displaystyle \mathrm{T}=4$ seconds. If the sides of the triangle are increased to length $\displaystyle 2 a$ and also the masses of the spheres are made $\displaystyle 2$ m , then they will collide after $\displaystyle \_\_\_\_$ seconds.