# Physics

### Answers

The formula v(y)=g(t/2) is derived from the kinematic equation v = u + at, where v is the final velocity, u is the initial velocity, a is the acceleration due to gravity, and t is the time elapsed. By rearranging the equation, we get u = v - at, where u is the initial velocity. In a free-falling motion, the acceleration due to gravity (a) is constant, so if we know the final velocity (v) and the time elapsed (t), we can calculate the initial velocity (u). In this case, v = g(t/2), because the calculated initial velocity is half of the potential velocity (which is equal to the acceleration due to gravity).