
Answer:
 t = 2 v₀ / g
Explanation:
For this projectile launch exercise we use the displacement equations
    x = vox t
    y = y₀ + [tex]v_{oy}[/tex] t - ½ g t²
As it is launched horizontally the vertical velocity is zero and the point of origin of the coordinate system is here, so yâ‚€ is zero.
    x = v₀ t
    y = ½ g t²
They ask us for the time for which
    x = y
    vo t = ½ g t²
     t = 2 v₀ / g