If we use the Lorentz equation for the length contraction, and the Schwarzschild equation for the lightlike sphere, we can calculate the velocity for the object to form a black hole:
$ \Delta x^{'}=\Delta x\,\sqrt{1-\dfrac{v^2}{c^2}}\,\, $ --> Lorentz formula
$ r_{\text{s}}=\dfrac{2Gm}{c^2}\,\, $ --> Schwarzchild formula
$ 2r_{\text{s}}=\Delta x^{'}\,\, $ --> to a sphere
$ 2\left(\dfrac{2Gm}{c^2}\right)=\Delta x\,\sqrt{1-\dfrac{v^2}{c^2}} $
$ v=c\,\sqrt{1-\left(\dfrac{4Gm}{\Delta xc^2}\right)^2} $
Is this correct? Is this the speed that the object, in the spherical case, would have to attain to become a black hole?
Sorry for my English and little knowledge of physics, I am a freshman student in a university in Brazil.
