Question

can someone please explain how to get the formula v=gt

Answer 1

Am I understanding this is the velocity given gravitational acceleration, g?
There are a few ways you would come about this formula. One way is simply by experiments and data. You would obtain a linear relationship between v and t with a constant of proportionality equal to your value for g.

You might also obtain it from Calculus knowing that acceleration is constant and initial velocity is 0. a = g, then take the antiderivative for velocity: v = gt + C. If we called initial velocity 0, then this reduces to v = gt.